|
|
03-10-2021, 04:34 PM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
M48 Light Hammer Strike
Hello. Long time listener, first time caller....
I've been an acquirer of firearms since I was a kid, but mostly old rifles and shotguns. Was not really that into sidearms until I was purchasing a couple Savage 1899s out of a collection and ended up with 3 S&W revolvers as part of a package deal because my wife was interested in two of the revolvers and I had been thinking of getting a .357 for awhile. I got a M48 no dash, M13-1 and M12-2. The M48 and M13-1 were duracoated or ceracoted to look stainless but I paid about $100 each for them and figured they would make good shooters. The 13-1 is the best pistol I've ever shot. I can't say enough good things about it, it's just perfect for me maybe. My next S&W is going to be a 1905 in .32-20 because I have more than a few rifles chambered in that round. And I plan on getting another M13. Also have a 4516 I really like.
Anyway, the M48. From SCS&W puts it as being made in 1959. It's fun to shoot and is my wife's favorite gun. I'm going to either blue it myself or have it blued. I've rust blued a lot over the past 20 years and have gotten pretty good at it. And am considered good at metal refinishing. Not sure how to get the coating off it, which is the reason I may pay someone to do it. Before it gets refinished I need to take care of one problem. Seems it has a case of light hammer strikes. It was doing it about 50% of the time on the first strike, but then the round would go off on the second strike. If it matters I only really single action shoot. So I completely took it apart and cleaned it. It hadn't been cleaned in a loooong time, but appeared to have been generously oiled often. So got it cleaned up, reassmbled and test fired it. Action was a lot smoother and it only wouldn't fire about 25% of the time.
My thinking is that the main spring is worn out. Does this actually happen? Another thought is someone replaced the main spring with a lighter one. I suppose someone may have shortened the tension screw but I'm fairly certain that is not the case. I've only tried Winchester 22mag ammo, but have tried ammo out of different boxes with the same results.
My question is, is purchasing a new factory power Wolff spring the right next step?
Thanks.
|
The Following User Likes This Post:
|
|
03-10-2021, 07:36 PM
|
|
US Veteran
|
|
|
Join Date: Dec 2010
Location: Atlanta area
Posts: 8,992
Likes: 16,232
Liked 19,844 Times in 4,482 Posts
|
|
I say go for it, if you are sure the strain screw has not been shortened. I have used Wolff springs in my shooters with good results. I'm usually putting in reduce power springs being mindful of light strike with a variety of ammo brands.
|
The Following User Likes This Post:
|
|
03-10-2021, 07:51 PM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
Quote:
Originally Posted by Retired W4
I say go for it, if you are sure the strain screw has not been shortened. I have used Wolff springs in my shooters with good results. I'm usually putting in reduce power springs being mindful of light strike with a variety of ammo brands.
|
Is there a standard measurement for the strain screw? If it does have the original spring in it, I'd like to keep it.
|
03-11-2021, 12:03 PM
|
|
US Veteran
|
|
|
Join Date: Dec 2010
Location: Atlanta area
Posts: 8,992
Likes: 16,232
Liked 19,844 Times in 4,482 Posts
|
|
Not that I can find in my books. You might have better luck posting your question in the smithing section. There are several experienced armorers there who could help.
The 48 is on my "looking for" list these days. I have owned two, but sadly I sold them.
|
03-11-2021, 12:33 PM
|
Member
|
|
|
Join Date: May 2010
Location: The Steel City
Posts: 2,158
Likes: 6,838
Liked 4,405 Times in 1,409 Posts
|
|
If you post a photo of the grip frame with the stocks removed we can see the arch of the mainspring and it will give a good indication of proper strain screw length.
|
The Following User Likes This Post:
|
|
03-22-2021, 11:39 PM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
I thought I'd get an email if someone posted to my thread but I did not. Glad I checked. Let me know if this picture is good enough to see the arch of the spring.
Thanks.
Last edited by damnesia; 03-22-2021 at 11:40 PM.
|
The Following 2 Users Like Post:
|
|
03-23-2021, 12:06 AM
|
SWCA Member
|
|
|
Join Date: Aug 2012
Location: central Texas
Posts: 1,132
Likes: 2,776
Liked 1,287 Times in 636 Posts
|
|
Cylinder end-shake (forward-backward play) can also be the culprit. With the gun empty, let the hammer down into the fired position and hold the trigger to the rear. Attempt to move the cylinder back and forth. Do this for each chamber. If you find noticeable play, a new spring may not be the cure.
__________________
Mike H
|
The Following 2 Users Like Post:
|
|
03-23-2021, 12:15 AM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 239
Likes: 0
Liked 253 Times in 126 Posts
|
|
Are the misfires with factory ammunition or reloads?
The characteristic of a misfire firing on a second firing pin strike is commonly seen when the primer is not fully seated. Rare with factory ammunition, somewhat more common with reloads.
|
03-23-2021, 01:06 AM
|
Member
|
|
|
Join Date: Jan 2006
Location: Escaping CA to OR in 2024
Posts: 1,182
Likes: 1,165
Liked 1,466 Times in 592 Posts
|
|
Quote:
Originally Posted by damnesia
I thought I'd get an email if someone posted to my thread but I did not. Glad I checked. Let me know if this picture is good enough to see the arch of the spring.
Thanks.
|
Looks like there should be a bit more bow to that mainspring.
|
The Following User Likes This Post:
|
|
03-23-2021, 01:35 AM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
There might be a tiny amount of end shake on one cylinder. I tried measuring with a feeler gauge but I couldn't find one that was thin enough, so if there is end shake i think it's like .001 max. Would that be enough to cause the problem?
These are .22 magnum factory loads.
Maybe I'll look for a new tension screw. Is this something I can find in the proper length or will it require tweaking to get it adjusted?
Thanks.
|
03-23-2021, 02:17 AM
|
|
Member
|
|
|
Join Date: Jan 2012
Location: OVER the hill in TEJAS
Posts: 2,725
Likes: 13,107
Liked 4,339 Times in 1,773 Posts
|
|
Don't try to bend the spring. You can back the screw off and install a spent large primer under the screw and retighten until you get a new spring.
|
The Following User Likes This Post:
|
|
03-23-2021, 07:13 AM
|
Member
|
|
|
Join Date: Jun 2001
Location: Florence, Alabama, USA
Posts: 2,349
Likes: 40
Liked 1,397 Times in 773 Posts
|
|
I would get a fresh S&W spring, the Wolff lets the strain screw drop down in the groove and reduce the preload.
An 8-32 set screw will let you apply as much strain as you like.
|
03-23-2021, 08:13 AM
|
|
US Veteran
|
|
|
Join Date: Jul 2010
Location: Denver, CO
Posts: 2,266
Likes: 858
Liked 4,405 Times in 1,084 Posts
|
|
For strain screw and hammer spring questions read Revolver trigger job questions which shows the S&W Armorers manual answers to your questions.
Stu
|
03-23-2021, 08:38 AM
|
|
US Veteran
|
|
|
Join Date: Feb 2016
Location: western NC
Posts: 3,055
Likes: 2,543
Liked 6,888 Times in 2,153 Posts
|
|
Quote:
Originally Posted by ReloadforFun
Are the misfires with factory ammunition or reloads?
The characteristic of a misfire firing on a second firing pin strike is commonly seen when the primer is not fully seated. Rare with factory ammunition, somewhat more common with reloads.
|
OP is shooting .22 Magnum Rimfire. No separate primer to seat, and not reloadable.
How tight are your chambers? Will your rounds drop in easily and seat fully without pushing them? I have a similar issue to yours with my M48-4, a good deal newer version (mine is from 1981). If there is the least amount of powder residue in the chambers, the rounds don't fully seat, but look like the do, the back of the case head is still flush with the cylinder, to look at them. I'll get one or two FTF's on a cylinder, but they always fire the next time around, from being driven to fully seated by the previous hammer strike. If I look at the failed cases before trying the second time, the pin strike looks just as indented as the ones that fired. I've only shot CCI ammo in mine.
This happens on either single or double action, and only starts after the 3rd cylinder load or so, after starting with a clean gun. If I blow out the chambers between reloading, I get much fewer FTF's which leads me to think mine is an issue with the rounds not properly seating. My chambers are fairly tight and even when clean, I have to push the rounds into a seated position. Mine has no end shake and the action is tight, and strain screw properly tight. I don't think my gun has been fired very much before I bought it, no usual wear on the finish and cylinder looks "unused" for lack of a better description.
I love shooting this gun, it's very accurate, but the issue is irritating.
Last edited by Hair Trigger; 03-23-2021 at 08:41 AM.
|
03-23-2021, 10:51 AM
|
SWCA Member
|
|
|
Join Date: Feb 2006
Location: Charleston SC
Posts: 1,521
Likes: 3,791
Liked 1,844 Times in 469 Posts
|
|
I had this problem on my Model 48 and solved it simply by shoving the rounds all the way into the chambers.
What was happening was the rimfire rounds were taking the first strike (about half the time) to SEAT them and the second hit would fire them.
The magnums are long and need to be purposely seated. I think you may find this solves much of the issue.
|
03-30-2021, 09:06 PM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
I bought a new spring from midwest gun works and a tension screw too. The screw looks like it was for a round butt even though it was stated to be for a square butt, it was way shorter than the one in the gun. So I replaced the spring. The new one was about identical but had a slightly differ bend at the top. The hammer pull is now more stiff and after firing 50 rounds through the gun, every round fired as expected. I like the feel of it with the new spring too. And I like that it's a flat spring with no rib.
|
The Following 4 Users Like Post:
|
|
03-31-2021, 11:19 PM
|
|
Member
|
|
|
Join Date: Sep 2001
Location: Grinder's Switch, TN
Posts: 1,680
Likes: 1,440
Liked 1,444 Times in 664 Posts
|
|
Quote:
Originally Posted by damnesia
I bought a new spring from midwest gun works and a tension screw too. The screw looks like it was for a round butt...
|
Do you have another square butt K frame you can compare strain screw length with? And did you clean under the extractor star? If there's any gunk at all under the extractor, it can act like a cushion when the firing pin hits the rim of the cartridge. It's usually worse with .22 LRs than with .22 Mags due to the lube on bullets, but it needs to be well cleaned - even with magnums.
Mark
__________________
S&W Forum Member #721
|
03-31-2021, 11:47 PM
|
SWCA Member
|
|
|
Join Date: Apr 2011
Location: Northern Middle Tennessee
Posts: 2,915
Likes: 3,428
Liked 4,120 Times in 1,462 Posts
|
|
Welcome to the forum sounds like you got your problem sorted out. It also sounds like you got some good shooter grade guns to boot. The old 99 Savage rifles were a marvel of engineering. Perhaps you could post pictures of those in the appropriate section of the forum
__________________
Randy
|
04-01-2021, 12:03 AM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
Quote:
Originally Posted by wheelgun610
Do you have another square butt K frame you can compare strain screw length with? And did you clean under the extractor star? If there's any gunk at all under the extractor, it can act like a cushion when the firing pin hits the rim of the cartridge. It's usually worse with .22 LRs than with .22 Mags due to the lube on bullets, but it needs to be well cleaned - even with magnums.
Mark
|
I have a model 13, which I believe is a K frame, so I may compare the screws.
I did clean under the extractor when I deep cleaned the gun. It's very clean.
|
The Following User Likes This Post:
|
|
04-01-2021, 12:05 AM
|
Member
|
|
|
Join Date: Feb 2021
Posts: 7
Likes: 0
Liked 9 Times in 5 Posts
|
|
Quote:
Originally Posted by merl67
Welcome to the forum sounds like you got your problem sorted out. It also sounds like you got some good shooter grade guns to boot. The old 99 Savage rifles were a marvel of engineering. Perhaps you could post pictures of those in the appropriate section of the forum
|
Thank you, it's good to be here.
The 99s are my favorite rifle of all time. I may post some pics if I can find where they should go. I've got 33 of them, so will only post pics of some of the good ones
|
The Following User Likes This Post:
|
|
04-01-2021, 10:00 AM
|
|
Member
|
|
|
Join Date: Feb 2016
Location: Midwest
Posts: 1,723
Likes: 986
Liked 1,966 Times in 837 Posts
|
|
This comes a bit late in the discussion , but here is something else for you to keep in mind for future reference ---
I have a K frame .38 that I tuned for range shooting. Reduced springs were part of the process. I was occasionally getting ftf in da , but not in sa , so I concluded that I was right on the edge of sufficient striking force. Rather than reinstalling the stock hammer spring I employed an old trick - I extracted a spent primer from a casing , cleaned the guts out of it , and placed it over the end of the strain screw thereby effectively lengthening the screw slightly.
The result was consistent ignition and a trigger pull that was still noticeably less it was with the stock spring.
2 points to be made for clarification:
- I know that the OP was working with a rimfire revolver , but light strikes are light strikes.
- Obviously , such a modification would be inappropriate for any firearm intended for self defense. As stated earlier , my subject revolver is strictly a range gun , one that now has very smooth da trigger at about 7.5#. Single action is really an attention getter , inside of 2#.
Last edited by Waveski; 04-01-2021 at 10:02 AM.
|
The Following 2 Users Like Post:
|
|
04-01-2021, 06:11 PM
|
Member
|
|
|
Join Date: Mar 2010
Location: dubuque ,iowa
Posts: 679
Likes: 18,221
Liked 570 Times in 236 Posts
|
|
This is my 48 no dash. I have a lot of similar problems with newer ammunition, where as older ( 10 years plus Winchester) fires every time. Brushing chambers every couple rounds helps and pressing cartridges in fully when needed , basically every time but still getting ftf’s but firing on 2nd hit . Quality control since the last shortage ?? Ammunition tried Armscor, Winchester, Hornaday, can’t find cci. I also question my strain screw . To test do you use a small or large primer? How’s this spring look?
|
04-01-2021, 09:56 PM
|
|
Member
|
|
|
Join Date: Feb 2016
Location: Midwest
Posts: 1,723
Likes: 986
Liked 1,966 Times in 837 Posts
|
|
It's really hard to judge the degree of curve in those two springs , but if I put a straight edge in place and compare the two it looks like mine has a bit more - but that doesn't mean much because of all the variables.
If you want to try the primer cup trick , I extracted the one in the picture from a spent .38 sp round , so it would be small pistol. It fits nicely over the end of the strain screw , no chance of falling out of place once it is under load. There is a bit of hardware (anvil?) in the primer cup that has to be removed.
It's a Cheap Trick ... "Surrender" and give it a go. . (Cheap Joke)
|
|
Posting Rules
|
|
|
|
|