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12-29-2023, 12:26 PM
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Normal Hammer block contact? Model 36
Is it normal to observe some contact marks from the hammer on the back of hammer block?
This is a c.1975 Model 36
I opened it up after having failures to fire (light primer strikes) in double action.
Internals were dirty (see photo), but also looked like the hammer had just kissed the top edge of the hammer block.
Arrows on photo indicated location of marks on block and approximate matching location on hammer.
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12-29-2023, 12:44 PM
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Negative, no it's not normal...
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12-29-2023, 02:38 PM
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If this persists after the thorough cleaning of the internals, you can crown the top edges of the "flag" at the top of the hammer block, and remove a small amount of material from the top of the flag. (note: The illustration is a K series hammer and hammer block, but the modification is the same)
The edge of the cutaway on the hammer, just beneath the hammer nose is not clearing the top of the hammer block as the hammer goes fully into battery.
If the hammer block cavity (hole) at the bottom that fits over the pin in the rebound slide is badly worn, you can always just replace the hammer block with a new OEM one.
Be sure not to cycle the action under pressure from the hammer spring while the sideplate is off. This can result in damage or breakage to the hammer stud, rebound stud or trigger stud.
[url=https://flic.kr/p/2og5ceq]
Carter
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Last edited by armorer951; 12-29-2023 at 03:28 PM.
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12-29-2023, 03:26 PM
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Thank you. Yesterday there was at least one misfire every cylinder when fired double action. So range firing should be a pretty good check. Previous two sessions there were no misfires.
Everything but the extractor and ratchet was removed and cleaned with Kerosene, then mineral spirits. A very little bit of arkansaw stone on rough edges and burrs. Cleaned again and drop of Remoil on bearing and rubbing surfaces.
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12-29-2023, 04:06 PM
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Not to get too far off the trail here, but just a reminder in terms of the many possible causes of misfires in DA..... "staging" the trigger in double action can cause what's called "hammer hits rebound". This "incomplete" rearward travel of the trigger in DA (staging) can result in the rebound seat on the hammer striking the hammer seat on the top of the rebound slide, causing the hammer to not go fully into battery, and cause misfires.
Just another thing to check for.....a little bit of "wink" (space) between those surfaces when the trigger is fully rearward and the hammer comes fully down.
Carter
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Last edited by armorer951; 12-29-2023 at 04:08 PM.
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12-29-2023, 08:58 PM
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Just for S&G's, make sure the hammer is not rubbing up against the frame or side-plate.
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12-29-2023, 10:36 PM
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Funny you mention that. There was evidence of rubbing on the side plate. I lightly went over the plate with a translucent stone and also broke the sharpness of the edge. The hammer I did not touch.
Observations as to whether that amount of contact could be a significant contributor are welcome.
Last edited by Matt_X; 12-29-2023 at 10:45 PM.
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12-30-2023, 10:39 AM
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Quote:
Originally Posted by Matt_X
Funny you mention that. There was evidence of rubbing on the side plate. I lightly went over the plate with a translucent stone and also broke the sharpness of the edge. The hammer I did not touch.
Observations as to whether that amount of contact could be a significant contributor are welcome.
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Once in a while a shim needs to be added. That rubbing looks to me like it is more than just the hammer block safety! I'd also check to make sure that the hammer is sitting all the way down on the stud. Dirt or debris could be raising it slightly and causing it to sit just a wee bit proud, causing rubbing.
Last edited by chief38; 12-30-2023 at 10:45 AM.
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12-30-2023, 11:32 AM
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If you really want to know if it is the hammer block(which I doubt) simply remove it and fire a few cylinders full.
I am with chief38 in believing your hammer is dragging. Those marks on the side plate and hammer show that.
Armorer951 gave some good thoughts and I will add that you should check for endshake.
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12-30-2023, 01:28 PM
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The only change I can think of between the first two times at the range and the third is additional accumulation and movement of dirt and grit.
That doesn't mean that underlying factors (such as hammer block contact, hammer rub, or rebound contact) aren't at the root of the issue.
I can certainly try adding shim to the sideplate side if there is enough side play.
There's about .004" endshake based on the cylinder gap measurement pushing forward and back; .008 to .004"
headspace is .067"
Shim sources for J-frame shims? triggershims dot com or mcmaster-carr?
Last edited by Matt_X; 12-30-2023 at 01:50 PM.
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12-30-2023, 03:13 PM
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Triggershims.com.
Steelslaver has pointed out a great way of determining if the hammer block is the culprit or not.....just remove it for a test fire session.
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12-30-2023, 05:50 PM
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Quote:
Originally Posted by armorer951
Triggershims.com.
Steelslaver has pointed out a great way of determining if the hammer block is the culprit or not.....just remove it for a test fire session.
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Normally I would agree, but in this case the hammer and side-plate are so marked up (been going on for some time), you would need to coat them with Dykem machinists dye first. If no Dykem is on hand, then a good old magic marker would work. Then yes, that is a good suggestion. Removed with alcohol afterwards of course. Dykem comes off easily as it is made to.
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12-30-2023, 08:05 PM
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That's a great idea. I have dykem and magic markers.
I can feel play in the hammer, so a shim may be a good idea anyway.
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12-31-2023, 11:01 AM
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Matt X,
Don't know exactly what the grease or grit is on your original photo, but it should not be reapplied after solving the issue here. Only a [U]light[/U] lubrication on the pivot and sliding points - that's it! Excess oil and or grease does little to help and lots to hurt because it attracts unburned powder. lint, debris, etc.
I can also tell you that the rearward most mark on the back of the hammer can not be from the hammer block safety because it can not touch it - too far rearward. Must be from side-plate.
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01-07-2024, 02:37 PM
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Who knows what lubes were on the mechanism when I bought it.
Triggershims was a good source. I like that they mark the thickness on the shim.
A few trials for rubbing and binding resulted in two .002 shims on the right side of the hammer. Also a .002 cylinder bearing shim.
While it was apart, here is a little better photo of peening I saw on the hammer block.
I think its good. It will be at least another week before I can get to the range.
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02-03-2024, 01:45 PM
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I got to the range and not solved.
As I failed to think out the 'what if' I didn't examine carefully the primers and document at the time. Likewise forgot to bring a screwdriver so I could trial without the hammer block.
However as far as the spent brass goes, there was one that clearly had a light strike. (photo shows a mix of single action and double action fired brass)
There is a little roughness in the hammer block channel, but I would think that a) movement is dictated by the pin on the rebound slide, and b) round slide in double action is in the same position single action.
Next post will be looking at the 'wink' between the rebound slide and the hammer's rebound.
Last edited by Matt_X; 02-03-2024 at 01:47 PM.
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02-03-2024, 02:00 PM
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There does seem to be a little space between the hammer and the rebound, although less so when releasing double action.
I'll let the photos do the talking here.
First one is with the trigger held at the point where the hammer releases.
Second is with the trigger all the way back.
Third is contact on with the trigger returning and the rebound slide moving forward.
This problem only showed up after its third trip to the range.
Only after the failures to fire did I open the sideplate. So whatever changed is probably subtle
Last edited by Matt_X; 02-03-2024 at 02:08 PM.
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02-03-2024, 09:21 PM
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When there is abnormal contact between the rebound slide and the rebound seat on the hammer when the hammer drops in double action, you can usually "hear" the difference in the sound of the hammer impact when it goes into battery.
When the parts are fit correctly, the hammer makes a very clear and loud "click" when it completes it's forward rotation and strikes the frame cutout. When the hammer seat on the rebound slide is a bit too far forward, the sound of the hammer impact is not sharp and distinct.....more like a dull thud.
In this scenario, misfires or "light" primer strikes can often be due to an incomplete follow through on the trigger by the shooter either because of improper trigger technique, or perhaps because of an attempt at "staging" the trigger rearward, instead of pulling it though completely.
If you determine the front of the hammer seat on the rebound is literally "in the way" at the completion of a clean and complete DA trigger pull, you can remove material from the front face of the seat to accommodate the hammer and make a bit more room here. The shape of the seat should remain the same. Another alternative would be to substitute a different rebound slide with a slightly shorter dimension at the front of the hammer seat interface.
Under no circumstances should material be removed from the top of the hammer seat on the rebound slide, as this is a critical part of the primary safety in the revolver.
Carter
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Last edited by armorer951; 02-03-2024 at 10:31 PM.
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02-04-2024, 12:55 PM
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@armorer951 Thank you. All the dry firing had been with dummy cartridges or spent brass. Trying the action both SA and DA the hammer is hitting the frame first. I can't say that was the situation before, but it clears up where that stands now. Now being after I touched up the angle on the front hammer seat so it is even all the way across.
Also, after better shaping the bevels at the hammer block top (again to be even and square all the way across) I coated the them with red Dykem. The red is all still there, so I think that's OK now.
Firing pin protrusion is around .044 or .045" (comparing with feeler gages). Khunhausen writes that he has measured .039 to .045" so I think thats OK. (He also suggests .055 to .062 max should be good, but I infer that is if one is replacing the nose)
Head space is about .063"
Finally, put Dykem on the back of the spent brass with the lightests primer indents ran them through in double action. All look to have decent strike marks now.
I think the next step is to go back the range.
Last edited by Matt_X; 02-04-2024 at 01:00 PM.
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02-11-2024, 07:51 PM
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This afternoon was the least successful range session since I bought this revolver. There were 2 out of five light strikes in single action, and consistant light strikes in double action.
I find this interesting in one respect, whatever is failing is getting worse. Not many mechanical things get worse that quickly.
To recap range sessions and work on gun:
1. 25 shots SA, 35 shots DA. Worked perfect.
Changed from Target stocks to Magna Stocks with grip filler
2. 30 SA, 30 DA. Worked fine
No changes. Just regular cleaning of chambers and bore.
3. 20 SA, 30 DA. Some failures to fire double action
Remove sideplate, clean, and try to identify causes.
Started this thread 29 Dec 2023
4. 10 SA, 10 DA. About 6 out of 10 Failure to fire double action. Second strike in single action generally fired.
Further work discussed above.
5. 5 SA with two out 5 light strikes, 5 Double Action all light strikes. (see photo)
Last edited by Matt_X; 02-11-2024 at 07:55 PM.
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02-11-2024, 08:30 PM
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You might check:
to see that the yoke is free of any end shake when it's in the gun and the yoke screw is installed.
Take a look at the hammer nose bushing and the condition of the frame cavity where the hammer enters the frame when going into battery. (use a magnifier) Also ck the hammer nose and rivet condition and movement.
Make sure the hammer is moving freely, and entering the frame cutout centered up with the hole in the hammer nose bushing. Could the added shim on the hammer stud be causing issues?
I would also shoot it without the hammer block, to make sure that particular part is eliminated from consideration in terms of the cause of the intermittent light strikes. I believe you already confirmed the protrusion of the hammer nose is adequate, and the rear gauge appears to be in spec.
Just some additional things to look at.
Carter
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Last edited by armorer951; 02-11-2024 at 08:31 PM.
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02-11-2024, 09:57 PM
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Is this with factory ammo?
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02-11-2024, 11:32 PM
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Quote:
Originally Posted by ms
Is this with factory ammo?
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Yes. First was a box of Ammo Inc 158 grn MJ, after that mostly Fiocchi 158 gn FMJ. Also ran some Browning 130 gr., Rem 158 gr LRN, Hornady 110 gr FTX to compare POI.
Point of Aim was target center.
The 110 FTX grouped low.
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02-11-2024, 11:58 PM
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Carter,
Thanks. My answers and questions interspersed.
to see that the yoke is free of any end shake when it's in the gun and the yoke screw is installed.
Yoke has no play at all.
Take a look at the hammer nose bushing and the condition of the frame cavity where the hammer enters the frame when going into battery. (use a magnifier) Also ck the hammer nose and rivet condition and movement.
The hammer nose looks OK to me, but I have not any experience here. I only have a 1942 Victory to compare with and Kuhnhausen.
Make sure the hammer is moving freely, and entering the frame cutout centered up with the hole in the hammer nose bushing.
I gently lowered the hammer observing from the back and from the cylinder side. The nose first contacts above the hole and then seamlessly rotates on contact and the nose slides through fairly centered.
Looking into the frame cavity we can see the hammer contact has favored the left side.
Could the added shim on the hammer stud be causing issues?
I think the answer is yes. One of the shims has deformed. That probably indicates too much pressure.
I would also shoot it without the hammer block, to make sure that particular part is eliminated from consideration in terms of the cause of the intermittent light strikes. I believe you already confirmed the protrusion of the hammer nose is adequate, and the rear gauge appears to be in spec.
That seems like a good plan. Process of elimination. I'm also going to remove one or both of the .002" shims. The range is a cross town so its also an excercise in patience.
Visually the hammer spring looks great. No kinks or divets or any signs of damaged coils. I assume its factory.
Last edited by Matt_X; 02-12-2024 at 12:07 AM.
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02-12-2024, 12:40 AM
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I've never been inside a J frame so I'm viewing this as a detective/mechanic....
Looking at the wear patterns on the hammer in post #7 (right side top, left side bottom rear of the stud boss) and the left side impact in post 24 makes me wonder if the hammer stud is bent slightly down and to the rear, causing the hammer to sit at just a bit of an angle. Have you been cycling the action a lot with the springs in and the sideplate off?
It could also be that the stud is straight and the mounting hole in the hammer is worn out of round. Does the hammer fit tightly onto the stud? Or does it wallow around a bit?
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02-12-2024, 11:20 AM
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Quote:
Originally Posted by Shotguncoach
I've never been inside a J frame so I'm viewing this as a detective/mechanic....
Looking at the wear patterns on the hammer in post #7 (right side top, left side bottom rear of the stud boss) and the left side impact in post 24 makes me wonder if the hammer stud is bent slightly down and to the rear, causing the hammer to sit at just a bit of an angle. Have you been cycling the action a lot with the springs in and the sideplate off?
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The accumulated dirt inside was sufficient clue for me to conclude the sideplate had not been previously removed. And even if so, not regularly opened and cleaned by the previous owner.
I have never cycled with the side plate off and the hammer spring installed.
Quote:
It could also be that the stud is straight and the mounting hole in the hammer is worn out of round. Does the hammer fit tightly onto the stud? Or does it wallow around a bit?
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There isn't much if any room for play with the hammer stud to its sideplate support. There is some play between the hammer stud and the bore in the hammer itself. Enough that when there is no spring installed there is hammer can be slightly wiggled side to side. I doubt the hammer wears because it is hardened. Stud wear is possible but I *think* the stud in question has not seen a lot use. I *think* the play is typical but someone with experience will have to answer that.
My understanding is the sideplay is limited by the bosses of the stud supports. When installing the hammer shims, the play is taken up until there is no movement and then remove .001 to .002" of the shimming.
The contact on the side of the hammer shown in the earlier photos is certainly in part due to the allowable play in the hammer, and in part due to the rough finished (unfinished) surfaces inside the frame and sideplate.
As far as hammer contact inside the hammer recess of the frame - I can't answer. Hopefully Carter or some others with experience will have some insight there. However note that the wear through the bluing is cumulative from the life of the gun. I didn't think to go over that location with a marker or Dykem.
Last edited by Matt_X; 02-12-2024 at 11:26 AM.
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02-12-2024, 02:48 PM
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Just to add to all the great info already offered,
the factory J frame mainspring should have 26 coils.
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02-23-2024, 09:14 PM
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Some improvement at the range.
Out of 70 rounds double action without the hammer block, there were 7 failures to fire on the first strike.
With the hammer block installed, there was one failure to fire out of 30 rounds double action. Five of those were Browning cartridges (winchester brass) and may have softer primers.
So the hammer block is not delaying the hammer now, if it ever was.
The chamber was not the same from one misfire to the next.
With the sideplate off at the range, there appeared to still be some contact of the hammer with the frame and sideplate. Will get a better look tonight.
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02-23-2024, 11:43 PM
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And a little deeper look confirms marker has been rubbed off.
Although the bluing inside the frame where the hammer goes is there.
A thought came to me while thinking about pressure from the spring possibly pushing the hammer toward the sides. Is something not centered or squared?
How about the hammer spring's strut?
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02-23-2024, 11:52 PM
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Please excuse my poor memory, but have you already confirmed that the hammer spring is an OEM mainspring? (closed and flat ground at each end)
Can you check to confirm there is no impact (touching) of any part of the bottom of the hammer to the top of the rebound slide when the the hammer goes fully into battery? That impact could be intermittent. The stirrup of the trigger can put quite a bit of upward tension on the rebound, if the stirrup is not straight. In this case the stirrup can push on the front of the rebound at an odd angle....sometimes even a slight upward angle, which could cause the rebound to be in the way as the hammer comes down.
Can you measure the overall height of the rebound slide, from the bottom, to the top of the hammer seat?
Also, I'm wondering if you mark the sides of the hammer and dry fire with the sideplate on, where the scuffs are. If the hammer is scuffed, what if you mark it and then dryfire without cinching down the sideplate.... leave the back two screws backed out a full turn. Does the hammer still get scuffed in this scenario?
Thanks
Carter
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Last edited by armorer951; 02-24-2024 at 12:52 AM.
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02-24-2024, 09:12 AM
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Carter,
I appreciate the questions. It can be hard to keep track of other people's projects especially when days or weeks go by between posts.
Hammer Spring: Seems to be ground flat, 26 coils, but I'll remove it from the strut this morning to check it.
Hammer Spring Strut: See the photo in my previous post? It sure looks bent. Perhaps a clue someone was in there before me and leaned or pried on it??
Could that be pushing the hammer to one side?
Hammer to Rebound Slide Contact
The photos from before are about as well as I can see.
It looks to me like the trigger stirrup is pushing the rebound slightly downward. When I remove the rebound slide we can take a look for side bending.
Hammer side scuffing
Interesting experiment you suggest. Will try that this morning too.
When I removed the sideplate to instal the hammer block the yoke and center screws were not tight. So the last 30 shots were fired with tight screws as well as the hammer block.
Last edited by Matt_X; 02-24-2024 at 09:14 AM.
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02-24-2024, 11:03 AM
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Main Spring Dimensions:
I count 27 1/2 full coils. Photo below so others can check my counting. For calculating spring rate, active coils are based on total coils less end coils. But if someone has a factory spring they can check for total coils and if the end finish matches, that would be really helpful.
Free Length = 1.730", Coil Outer Dia. = 0.205", Wir eDia. = 0.033"
Measurements are with a cheap dial caliper so plus minus .001"
Hammer Spring Strut:
a. Bent in middle.
b. Yoke is rounded over with a bevel on the side which is bent inward. Could it be so soft that it is wear? Or someone's filing?
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02-24-2024, 11:18 AM
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The bent strut is not helping anything. It needs to be flattened out. It is part of the problem, but no telling what percentage. Possibly a low percent.
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02-24-2024, 11:25 AM
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Fair enough. Thank you.
It was softer than I expected. Its flat now and the corners light stoned.
On Jack's First there are both flat struts (Stirrups) and round ones. Presumably the flat versions are were made later for cost savings?
He also has a photo of factory springs. Some are in the white and others in the black. The top shiny one is 26 coils by my count, and the blued one at the bottom is 27 + coils. Its free length seems to be a fraction longer than the one I removed.
Smith & Wesson old model J frame 1957-1988 >> Jack First Inc. - Page 3
Last edited by Matt_X; 02-24-2024 at 01:22 PM.
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02-24-2024, 01:34 PM
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Quote:
Originally Posted by armorer951
The stirrup of the trigger can put quite a bit of upward tension on the rebound, if the stirrup is not straight. In this case the stirrup can push on the front of the rebound at an odd angle
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There's a little bit of side play but nothing that looks bent.
Quote:
Originally Posted by armorer951
Can you measure the overall height of the rebound slide, from the bottom, to the top of the hammer seat?
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0.281"
Hammer stud diameter = 0.122"
Last edited by Matt_X; 02-24-2024 at 02:02 PM.
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02-24-2024, 02:08 PM
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The overall height of the rebound looks a bit high, but not out of spec. The ones I have here are .278".
Is the peening still happening to the hammer block flag? The photo in post 15 looks as if the corner of the hammer cutout just below the hammer nose is striking the flag as the hammer drops. That shiny artifact shouldn't be there.
Perhaps you could try substituting a different hammer block?
Carter
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Last edited by armorer951; 02-24-2024 at 02:11 PM.
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02-24-2024, 04:31 PM
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Minor but maybe helpful changes upon reassembly.
Main Spring was assembled to strut with the paperclip on the opposite side of the chamfer. My reasoning is this chamfer allows clearence for the rod's yoke to be assembled into back of the hammer without bending.
A little more honing to remove edge burrs on the sideplate.
All of the scuff areas were cleaned and coated with red dykem. (red because the blue went bad).
Revolver was assembled. Sideplate screws were backed out 1 turn each. Stocks were installed without retaining screw. About 30 double action dry fires (with spent cartridges installed).
No scuffing of the Dykem observed except maybe a little on the right and top of the firing pin nose.
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02-24-2024, 05:03 PM
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Reassembled with the sideplate screws tight.
Again no scuffing observed after 25 trigger pulls except at firing pin nose and a little on the hammer block chamfer.
Since the higher percentage of failures to fire occured without the hammer block installed, if that's a contributor to the problem its a more minor one.
It seems to me straigtening and inserting the main spring strut the other way has helped.
I think its still possible the rebound needs a little more chamfer. Maybe before touching that it might be worth experimenting with a .003 hammer shim instead of the .002" although .004 was certainly too thick.
Last edited by Matt_X; 02-24-2024 at 05:04 PM.
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02-24-2024, 05:06 PM
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The continued inconsistency here, both in SA and DA sounds to me like the rear edge of the rebound seat on the hammer is hitting the front edge of the hammer seat on the rebound as the trigger is pulled fully back, and hammer attempts to go fully into battery. The images are excellent, but this my gut feeling, if there is such a thing.
Of course, as always, this is very hard to diagnose without hands on.
I can send you some new components if you would like to try switching some parts out one at a time.
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Last edited by armorer951; 02-24-2024 at 05:07 PM.
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02-24-2024, 06:23 PM
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Quote:
Originally Posted by armorer951
The continued inconsistency here, both in SA and DA sounds to me like the rear edge of the rebound seat on the hammer is hitting the front edge of the hammer seat on the rebound as the trigger is pulled fully back, and hammer attempts to go fully into battery. The images are excellent, but this my gut feeling, if there is such a thing.
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I can see what you are saying when I observe the relationship pulling trigger very slowly to thet point of releasing the hammer.
If it makes a difference, the only time single action failed was with two 0.002" hammer shims (.004" total) on the right side. This last session I shot one full cylinder single action, plus cleared a failure to fire using single action. So I think single action back to working.
Quote:
Originally Posted by armorer951
Of course, as always, this is very hard to diagnose without hands on.
I can send you some new components if you would like to try switching some parts out one at a time.
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That sounds like a good idea and I appreciat the offer.
Would it make sense for me try a little more work on the rebound's chamfer first?
Last edited by Matt_X; 02-24-2024 at 06:26 PM.
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02-24-2024, 06:25 PM
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I wouldn't worry about .001 of hammer shim. Just run with the .002. It will be fine.
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02-24-2024, 07:04 PM
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Sure. Moving the front edge of that hammer seat back a bit more may just solve the problem. I can't think of anything else that would cause these kinds of inconsistent primer strikes. The integrity of the hammer nose and the hammer nose bushing have been confirmed. There's really nothing else in the pathway of the hammer at this point.
Carter
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02-25-2024, 05:07 PM
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Took that leading corner of the rebound back a bit yesterday evening.
This morning I thought it would not hurt ot further investigate the hammer nose and the shims. Since there still is a little contact favoring the right side of the hammer and hammer nose, why not.
Hammer freedom was compared with the main spring removed.
Swapping to the .003" hammer shim revealed a little bit of friction as the hammer completes its forward motion. Hardly noticible but not worth the risk.
Hammer nose has freedom of movement in the full forward (firing) position. But there was a little roughnous depending on if it touched a little to the left side.
So (a) very lightly stoned the nose circumfrance on the left to radiuse the corners and smooth the ridges.
(b) filed the rough contact visible on the left side of the frame cavity. Probably could do more there.
The action sounded snappy with snap caps, but that's fooled me before. I ran a piece of aluminum foil behind the dummy cartidges and the punchs look OK (but don't know if that proves anything). I'll report back when I get to a range and test it for real.
Last edited by Matt_X; 02-25-2024 at 05:12 PM.
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03-06-2024, 04:20 PM
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Not quite there yet.
First three cylinders fired without a hitch which was an improvment.
Fourth cylinder had the first failure on first strike double action.
It fire on second strike, also double action.
The misfire was after a slow trigger pull - not quite two stage but close enough I thought it could be a contributor.
But then there was a failure to fire every 5 to 10 rounds after that. Grand total of 4 failures to fire on the first pull out of 40 with Fiocchi, and 1 failure to fire on the first strike with 15 or so Precision One 125 gr FMJ. Used up the rest of both boxes with a Victory with no hitches.
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03-06-2024, 05:17 PM
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Have you ever checked to see how far the hammer nose sticks out of the recoil shield with the hammer all the way down? It should be around .050, about the thickness of a dime. Variations in rim thickness, primer seating depth, endshake, etc, can become a problem if there is not enough protrusion.
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03-06-2024, 05:34 PM
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Quote:
Originally Posted by Protocall_Design
Have you ever checked to see how far the hammer nose sticks out of the recoil shield with the hammer all the way down? It should be around .050, about the thickness of a dime. Variations in rim thickness, primer seating depth, endshake, etc, can become a problem if there is not enough protrusion.
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Yes. Firing pin protrusion is around .044 or .045" (comparing with feeler gages). Khunhausen wrote that he has measured .039 to .048" so it seems one is close to factroy maximum. (He also suggests .055 to .062 max should be good, but I infer that is if one is replacing the nose) .p.79 5th edition
I just finished cleaning the cylinders and bore, so will take a look at the internals in a bit.
A little frustrating not being able to find a pattern.
Maybe I can check the main spring's force using a weight and wire coathanger?
Last edited by Matt_X; 03-06-2024 at 07:50 PM.
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03-06-2024, 06:05 PM
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Were you pulling the trigger forcefully and completely to the rear during you double action pulls? An "incomplete" trigger pull can result in the rebound slide not being fully retracted.
Consequently, the rebound interferes with the hammer's full forward motion and impetus. The result is light hits on the primer.
Carter
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Last edited by armorer951; 03-06-2024 at 06:10 PM.
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03-06-2024, 06:18 PM
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Quote:
Originally Posted by armorer951
Were you pulling the trigger forcefully and completely to the rear during you double action pulls? An "incomplete" trigger pull can result in the rebound slide not being fully retracted.
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I beleive so but did not focus on that, which I should have after that first FTF. After all this did come up earlier in the thread.
As mentioned about I did catch myself pulling the trigger slowly when taking a more difficult shot. But it fired fine. It was the following shot that was the FTF. I'll have to pay more attention to whether I am short cycling the trigger.
Last edited by Matt_X; 03-06-2024 at 06:29 PM.
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03-06-2024, 06:51 PM
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How fast you pull the trigger makes no difference in the hammer fall. The hammer is always released at the same point regardless of how it got there. If the mechanism is correct, the rebound slide will be far enough back when the hammer comes off the trigger. Maybe if the trigger pull is just barely enough, the rebound spring might move it forward a bit as the hammer is falling.
Short stroking the trigger is when you don't let it return quite all the way and it locks up the action until it does go all the way forward.
Last edited by Protocall_Design; 03-06-2024 at 06:54 PM.
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03-06-2024, 07:35 PM
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Quote:
Originally Posted by Protocall_Design
How fast you pull the trigger makes no difference in the hammer fall. The hammer is always released at the same point regardless of how it got there. If the mechanism is correct, the rebound slide will be far enough back when the hammer comes off the trigger. Maybe if the trigger pull is just barely enough, the rebound spring might move it forward a bit as the hammer is falling.
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With the sideplate plate off and main spring out, moving the trigger to the point it will just release its close but seems the hammer can be moved forward to contact the frame before hitting the rebound. Still, I'll have to make a note to be sure to pull the trigger all the way to the the trigger guard just to be sure I'm not causing the problem as you describe.
Quote:
Short stroking the trigger is when you don't let it return quite all the way and it locks up the action until it does go all the way forward.
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Thank you for explaining that.
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