625PC Hammer weight Adjusting

[H Richard]

What the heck is wrong with 11lb4oz DA and 4lb2oz SA????? Learn to shoot and quit playing with fixing something that isn't broken! By the time you shoot 500 rounds in practice you will love the trigger pull. Jerry M puts "Heavier" springs in his revolvers to get faster on the trigger.

 

[tomcatt51]

What the heck is wrong with 11lb4oz DA and 4lb2oz SA????? Learn to shoot and quit playing with fixing something that isn't broken!

Doesn't mean it can't be made better. If you prefer an 11 or 12 lb DA pull that's fine by me. I'll take my "massaged" guns. If I only casually shot paper or plinked I might not go to the lengths I do but a 5 1/2 lb DA pull is a joy compared to the factory 12ish lb pull.

Jerry M puts "Heavier" springs in his revolvers to get faster on the trigger.

His exhibition guns may (probably?) have a heavier rebound spring but one of the fellas I shoot USPSA with has shot Jerrys' USPSA 625 at the chronograph station of a major match. He said it felt no different than the rest of the 5ish lb DA pull revolvers he shot there. If the "heavier" rebound spring you allege, and is commonly repeated (ad nauseum) on the internet, was used it would have stuck out like a sore thumb. No missing it.

 

[Bearbait in NM]

H,

When it comes to triggers, I tend to fall in the camp that thinks triggers can be adjusted (or not) based on the intended use of the gun. And I feel this way for both rifle and handgun. And I have many guns, long and short that have tuned triggers, and stock triggers.

For this gun, my goal is to reduce some, but stay heavy enough that any ammo or primer will go bang. What I have learned so far:

1) Inspect gun, inside and out to make sure you have no burrs or anomalies that are not part of the design. I would say do this before doing anything else.

2) polish moving parts inside, and lubricate and dry and live fire the heck out of it before even thinking about springs. I did not love my trigger pull after doing just this, but things did get smoother. And a little lighter. I certainly wasted time just changing out springs right from the get go.

3) This is the point that I would experiment with springs, shims, etc.

We change grips to fit our hands, sights to suit our eyes, why not action parts to suit our use and ability?

Craig

 

[Bearbait in NM]

I thought another follow-up might be in order, as Tom is sending folks to this thread on occasion. We covered so much ground, I am pleased that anyone would find it useful ;^)

After all of the above, it is looking like about 9 lbs is what I need for reliable ignition with CCI and Winchester primers, With the Wolff reduced power springs and either the Apex, C&S or stock S&W firing pin.

Something else I have noticed while dry firing, that I have not had a chance to isolate/test is the fact that when the firing pin hits the round under the hammer, I can see my entire moonclip (with snap caps) move forward. Much like the argument that a tall seated primer might end up just finish seating and not go bang, it seems to me that somehow this situation could manifest itself as an issue in certain circumstances or combinations of replacement parts for the action job.

I have not seen much of any discussion of this anywhere on the net. Perhaps it is a non-issue. perhaps the mass of the clip with all the other rounds acts like a 1911 extractor and allows for ignition without the round forward on the stop ledge, or the the clip not flush to the cylinder? Either way, it seems logical to me that once you are pushing the low threshold of ignition, that this might be an issue.

Craig

 

[tomcatt51]

I thought another follow-up might be in order, as Tom is sending folks to this thread on occasion. We covered so much ground, I am pleased that anyone would find it useful ;^)

After all of the above, it is looking like about 9 lbs is what I need for reliable ignition with CCI and Winchester primers, With the Wolff reduced power springs and either the Apex, C&S or stock S&W firing pin.

Yes, this was/is a pretty good discussion that covered a lot of what is needed.

Not sure why you're needing 9 lbs to get reliability. 7 1/2 lbs usually seems to do it, hand seated CCI primers and a full hammer spur, but there are a lot of ways to make it heavier.

As to the "slop", there's always some. .006-.010" clearance IIRC. One thing you should do is load the moonclips so the square edge is towards the case rim, not towards the bullet. That helps a little. There's a "square" side and a "rounded" side on stamped moonclips. Most of these guns do headspace off the moonclips.

 

[Bearbait in NM]

Tom,

That is interesting. I absolutely load my clips just the opposite, square to the face of the cylinder. And not sure whether I saw a post here or over at the BE forum, that was making a mockery of folks who think a clip can be loaded "backwards". I probably looked at a hundred moon clip threads back when I bought my gun. Other than this one thread saying there is no difference, your post is the first I have seen even addressing the correct way to load them. Looks like I need to break out the feeler gauges again ;^)

I still need to rustle up a stock S&W .495 My earlier assessment that I was closer to 7 lbs sort of proved to be in error. Just a few too many misfires with more extensive testing. lately I have been focusing on load development with my heavier loads, and sort of decided to get a few thousand more pulls on firing and dry firing to see how things settle in. That and the fact that I am carrying the gun now at the ranch. Need 100% reliability.

Thanks for the moon clip info, I'll check that out for sure.

Craig

 

[tomcatt51]

...not sure whether I saw a post here or over at the BE forum, that was making a mockery of folks who think a clip can be loaded "backwards"...

Yep, seen that. The case has a flat rim surface that should sit on the flat side of the moon clip. Found this because when I first got a 625 I used aluminum bodied snap caps. Six had their rims trashed pretty quickly, the other six held up much better. The difference was how they were loaded in the moonclips. Flat side of the moonclip against the flat rim surface is best otherwise you're just "forming" the cases' rim to conform to the "rounded" moonclip contour. The other side against the cylinder, being steel on steel, doesn't matter.

Is it a big deal? No, but it's all the little things together...

 

[Bearbait in NM]

Tom,

Interesting. I just looked at my azooms which have a ton of dry fires, with the flat edge forward. The rims on the nose side of the bullet are really chewed up. Obviously the "sharp" edge of the clip flat against the taper of the case rim creates a less than ideal interface. In a minute way, I think this would tend to hold the case more reward as compared to the rolled clip edge against the sloping rim surface? And this point/knife edge contact is certainly harder on the brass, as the snap caps show. And this knife edge deformation into the forward brass rim edge could certainly in theory create a cushioning effect on the fp strike. Definitely some minutia going on here

I am acutely aware of how little things can add up when it comes to these systems we call firearms. Or subtract up ;^)

Craig

 

[tomcatt51]

Which rebound spring (weight) are you running?

 

[Bearbait in NM]

Tom,

I just double checked to be sure, 12 lbs. As I PM'd you. I will gladly give an 11 a spin.

Thanks,

Craig

 

[Bearbait in NM]

Final update, with some interesting results.

I scrounged up a .495 S&W titanium fp, and an 11 lb rebound spring. Did a lot of testing today, with some very good and useful results.

First, my major error. Earlier on, I noted going to hammer shims. I figured getting all of the play out of the hammer would be good. Later in the thread, I noted having to go back up a little higher on the poundage, to get reliable ignition. When I was installing the new FP, I checked the hammer play. With the gun a bit dirty, the hammer was dragging a little when tested loose. I took out one of the 2 .002's on the left side of the hammer. I should have accounted for dirt tolerances when shimming.

Today, all DA, testing the s&w .495 firing pin and 11 lb rebound with an Apex firing pin spring (which feels lighter than the s&W stock spring) I was able to get down to 7.5 pounds before seeing an occasional light strike on winchester primers, seated in very mixed brass, seated on my Dillon. The high ones would go bang second time around. No issues with CCI's hand seated. And when I say mixed brass, talking Amerc junk and lots of mystery headstamps. With Winchester brass, Dillon seated winchester, no issues.

I then got creative. As my gun will correctly headspace and fire without moonclips, I tested a bunch of this mixed brass high primer stuff sans clips. Got down to below 7 pounds with no issues. I did not test lower, because 7 really felt bad to me. It felt "too light". Hard to explain, but that is what I felt. The 11 lb return is also right on the edge for me.

What this seems to be saying to me is that there is a relationship between the moon clips and trying to get really light. If below 7 works without clips, and it takes 7.5 or so with clips, there must be some loss with the firing pin having to move the clip mass forward in some situations. In trying to save some ammo today, I only tested TK clips, and nickel ones that I think are Wilson. I have a couple of other brands that are terrible with mixed brass. Probably worth trying some different brands if going really light.

I tested the Apex .495 and Apex spring earlier, and I think the stock S&W titanium is the way to go, if you can get a .495. Mine came stock at .490. Either going with the Apex spring, or perhaps a clipped s&W firing pin spring sure seemed to help.

I did not test out any of my AR brass today, but based on the behavior of the non-clipped mixed brass, thinking the AR should allow for some really light numbers. I am going to set mine up at 7.5 to 7 3/4 and call it a day. With the smoothed up internals and weight at this level, the gun feels stunningly wonderful, compared to the stock 12 lbs.

Thanks to Tom and the others here who have helped me so much.

Craig

 

[linko]

Yes, all the little things add up. You should be able to get reliable ignition with hand seated CCI primers with a 7 1/2 lb DA pull, a 12 lb rebound spring and a full (non bobbed/lightened) hammer.

Might get a new S&W firing pin. they're now .495 and still titanium and seem to be optimal. Clip the firing pin spring so it holds the firing pin tip back about .030" (at most) from the recoil shield face when you just drop it in, cross pin not in place. Drop the spring in clipped end first. That's all it needs and you're then robbing as little as possible from the hammer fall. Do reinstall the firing pins' cross pin after shortening the spring.

The PC guns do come with a Wolff reduced power mainspring. There's a S&W part number for them.

The stainless S&W strain screws are horrid things. The alloy/heat treat is just wrong. They forever loosen and the tips deform. An 8-32 socket set screw works much better, doesn't deform, and stays in place better than the stock strain screw. A drop of 290 Loctite will guarantee that but they've also stayed put when I've forgot to loctite them after getting them adjusted. Filing a small notch in the socket end lets you index them for repeatable re-assembly.

Check the sides of the hammer for marks from dragging. The lock assy frequently drags on the hammer (good reason to take it out) and even without the lock assy the hammers frequently drag on their left side requiring a shim on the stud before dropping the hammer in place.

The rebound slide (as I think you found out) is the place you get the most from smoothing. Note I DIDN'T say polishing. Just a flat stone for the bottom and sides. Just taking off the high spots, those surfaces that look pretty good you find aren't after you see the pattern from a few strokes across a stone. 30 - 40% "shiny" and the rest black is plenty. You're really just flattening out the high spots.

The 625-8s benefit from having their chambers reamed. They're undersize and out of round round. You may be ok with brass that's only been fired in your revolver but you can have issues with brass that's been fired in a semi-auto, Glocks being worst. Your re-sizing can leave brass that is still too big (just above the extractor groove) to chamber and the rds don't drop in like they should. Reaming the chambers (SAAMI spec finish reamer) fixes that. Good time to chamfer the chamber mouths while they're being reamed.

The Kuhnhausen book is not very helpfull for this type of trigger work, Jerry Miculeks' "Trigger Job" video is much more usefull.

Have fun. The difference between 9 lbs and 7 1/2 lbs you'll find very noticable. 7 1/2 lb DA, 2 1/2 lb SA isn't a bad way to go.

Adding a shim on the hammer stud. That sounds like what I need. Are they available precut or do I need to make one? Thanks

 

[tomcatt51]

...shim on the hammer stud... .Are they available precut or do I need to make one? Thanks

Power Custom Hammer Sideplate Shims S&W K L N-Frame .002 Package of 10

 

[Flashooter]

S&W Trigger

I have three 627s 2 - 38 supers 1 - 357 and one PC 625 and a 1990 vintage 625. All five revolvers have double action trigger pulls right at 4 1/2 lbs. they are 100% reliable as long as I use Federal Primers. The mainspring has been slightly reduced in width. The strain screw has not been touched. The balance of the action work consists of reduced power rebound springs and polishing of the interior of the frame and hammer.

 

[Pdxrealtor]

Great info here guys. I'm left a bit confused on the firing pin selection.

I have the .495 S&W firing pin. With a 13# rebound spring and stock main spring set via strain screw being backed out I had to go up to 8 lbs to get reliable (actually just beginning stages of reliable).

My next move was going to be the C&S .510 firing pin as I've read this is a good solution. Is it not? I'm working with a 386 night guard, L frame, .357.

Thanks again for all the great info in this thread.

 

[tomcatt51]

My next move was going to be the C&S .510 firing pin as I've read this is a good solution. Is it not?

The C&S is NOT going to help. Keep the .495 S&W pin.

With a 13lb rebound spring I would expect you to have an 8+ lb pull to get reliable ignition. A lot of the work we do is getting the trigger to have a good rebound with lighter rebound springs. After removing any hammer drag and getting a mainspring/strain screw set that gives reliable ignition (much of) the rest of the work is getting a good trigger rebound with the lightest possible rebound spring.

Ultimately how light you can go is based on the mainspring. That's why we lighten hammers and use hand seated Federal primers, so we can run less mainspring. Rebound is balanced against mainspring.

 

[Pdxrealtor]

Thanks, Tomcatt, for the confirmation.

Two Questions:

1) What is the length of the strain screw from S&W. Mine appeared to be ground down already, and I went too far in taking it down farther. (Shoulda got the calculator out).

2) My 386NG has the 'mid target' hammer pictured below. What method of lightening removes the most weight? Trimming the sides, drilling several holes, one large hole, or ?

Spur width:

std = .265"
semi-target = .375"
target = .500"

I was going to have it trimmed anyways. Now that I'm into this thing I'll just do it myself.

 

[garbler]

Couple of observations take them for what they're worth to you

1. Hammer shims are not always drop in parts. At least 50% of the time you have to face off or remove a bit of the stud's boss on older models or riding surfaces on the frame or side plate to center up the hammer. It's trial and error fitting. Once done correctly you should have a perfectly centered hammer without any real side play.

2. Claiming a 4.5 pound DA pull on N frames or L's for that matter with reliable function is very hard to believe. I'd have to wonder how this was measured.

3. Installing a 11 pound or lighter rebound spring is asking for trouble down the road. This is the kind if thing that could cause an accident because some well intended shooter may not understand why the heavier factory spring was there in the first place. These light rebound slide springs can be marginal or too weak to set the hammer on the hammer seat --that elevated knob on top of the rebound slide. That and the hammer block are the only two safety features on these guns. The rebound slide has to have enough push to force the hammer seat up into position which in turn pushes the hammer face off the frame, letting the block slide in and making it impossible to accidentally hit the hammer and fire. So installing too light a rebound spring, looking for a quick and easy action job, and you can easily negate the major safety feature on your gun. Understand the more use the gun sees the more wear the spring and parts get and of course any accumulation of residue can make the lockwork sluggish.

Secondly reduced power springs will in fact slow down your DA trigger recovery time. I personally will tolerate an extra pound on the SA if it's creep free but not a balky slow DA trigger that if you're not careful will lock up the gun temporarily. I guess it depends on how you shoot your guns but my love has always been the fact that no other revolver can be slicked up like a K or L frame DA and no other revolver has faster lock time. As a rule of thumb you should never go lighter than a 12 pound rebound spring for normal use. For fast comp shooting a 14 pound may be preferable but it's personal taste. 12 pounds will still maintain safety and reasonably fast trigger cycling if the gun is clean and healthy. The only caveat is that hammer weight could be light enough to allow these sub-12 pound springs.

Regards

 

[tomcatt51]

Two Questions:

1) What is the length of the strain screw from S&W. Mine appeared to be ground down already, and I went too far in taking it down farther. (Shoulda got the calculator out).

2) My 386NG has the 'mid target' hammer pictured below. What method of lightening removes the most weight? Trimming the sides, drilling several holes, one large hole, or ?

1) They vary. I avoid the issue by using 8-32 (headless) socket set screws instead. Great range of adjustment but doing this is a sin according to some here...

2) .265s are the lightest stock hammers. I do everything from traditional bobbed hammers to drawing a line from the top of the hammer to just behind the pivot hole and cutting off everything behind the line. On an N frame MIM hammer that's a 50% weight reduction. It's amazing how fast that hammer falls with a stock mainspring and strain screw.

 

[Pdxrealtor]

Couple of observations take them for what they're worth to you

1. Hammer shims are not always drop in parts. At least 50% of the time you have to face off or remove a bit of the stud's boss on older models or riding surfaces on the frame or side plate to center up the hammer. It's trial and error fitting. Once done correctly you should have a perfectly centered hammer without any real side play.

2. Claiming a 4.5 pound DA pull on N frames or L's for that matter with reliable function is very hard to believe. I'd have to wonder how this was measured.

3. Installing a 11 pound or lighter rebound spring is asking for trouble down the road. This is the kind if thing that could cause an accident because some well intended shooter may not understand why the heavier factory spring was there in the first place. These light rebound slide springs can be marginal or too weak to set the hammer on the hammer seat --that elevated knob on top of the rebound slide. That and the hammer block are the only two safety features on these guns. The rebound slide has to have enough push to force the hammer seat up into position which in turn pushes the hammer face off the frame, letting the block slide in and making it impossible to accidentally hit the hammer and fire. So installing too light a rebound spring, looking for a quick and easy action job, and you can easily negate the major safety feature on your gun. Understand the more use the gun sees the more wear the spring and parts get and of course any accumulation of residue can make the lockwork sluggish.

Secondly reduced power springs will in fact slow down your DA trigger recovery time. I personally will tolerate an extra pound on the SA if it's creep free but not a balky slow DA trigger that if you're not careful will lock up the gun temporarily. I guess it depends on how you shoot your guns but my love has always been the fact that no other revolver can be slicked up like a K or L frame DA and no other revolver has faster lock time. As a rule of thumb you should never go lighter than a 12 pound rebound spring for normal use. For fast comp shooting a 14 pound may be preferable but it's personal taste. 12 pounds will still maintain safety and reasonably fast trigger cycling if the gun is clean and healthy. The only caveat is that hammer weight could be light enough to allow these sub-12 pound springs.

Regards

Good info! I pulled up a picture of my internals and see what you mean.

I watched my groups get wider and wider while tightening up the strain screw last night during reliability testing, so I'd like to go as light as possible down to the mid 7lb range.

That said, I want a reliable setup so will settle for a bit higher as a trade off.