fiVe
Member
Thanks for the update. I'll keep my fingers crossed for you.
642 - Light Firing Pin Strikes
- Thread starter Lord Bodak
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fiVe
Member
Lord Bodak: What is the latest?
Lord Bodak
Member
My revolver found its way back to me today. According to the included note, they replaced the cylinder. It doesn't say they test fired it but I sure hope they did considering the problem. I am planning to hit the range Saturday morning and if there are still problems there will be a not-so-nice phone call to them Monday morning. But I'm optimistic that they solved the problem and we'll find out soon.
If I may
I'd like to point out that I had the same problem with a used Model 19 I bought last year. My first revolver.
I found that my thumb (in a 2-hand grip) was rubbing the hammer and slowing it. Never happened in one-hand shooting. Corrected the bad habit and it never happened again.
I'd like to point out that I had the same problem with a used Model 19 I bought last year. My first revolver.
I found that my thumb (in a 2-hand grip) was rubbing the hammer and slowing it. Never happened in one-hand shooting. Corrected the bad habit and it never happened again.
Lord Bodak
Member
Khornet,
I'll keep that in mind in the future. However, since this is a 642 (fully enclosed hammer), I consider it highly unlikely in this case.
I'll keep that in mind in the future. However, since this is a 642 (fully enclosed hammer), I consider it highly unlikely in this case.
If all they did was replace the cylinder the most probable cause of your problem was excessive headspace. I suspect that the cylinder was forward far enough so that the firing pin didn't always reach enough to set off the primer. If they corrected the headspace your troubles should be over, but given that this style of revolver is usually used as a weapon it shouldn't have gone out in the first place. One wonders, what happened to quality control and basic inspections? Apparently the buyer is supposed to be the final inspector.
Headspace and firing pin protrusion can be checked with ordinary feeler gauges, of the kind sold in automobile supply stores to check spark plug gaps. Looks like buyers of (new) revolvers had better have a set. :banghead:
Headspace and firing pin protrusion can be checked with ordinary feeler gauges, of the kind sold in automobile supply stores to check spark plug gaps. Looks like buyers of (new) revolvers had better have a set. :banghead:
popeye
Member
Would it be worthwhile for some of you 642 owners to break out the calipers and compare notes?
fiVe
Member
Popeye brings up a good point, and I have another question:
How deep should a primer strike be?
I've shot 5 different kinds of .38 spl ammo in my 642 with no failures. I'm no expert, but none of the strikes were deep. I guess it doesn't matter as long as it is deep enough.
R/fiVe
How deep should a primer strike be?
I've shot 5 different kinds of .38 spl ammo in my 642 with no failures. I'm no expert, but none of the strikes were deep. I guess it doesn't matter as long as it is deep enough.
R/fiVe
StrikeEagle
Member
- Joined
- Jul 8, 2004
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- 709
I have a 642 in my pocket as we speak (158grn LHP +p ammo) and this is truly evil news to me...
Once you get it going, though it's the perfect pocket gun.
All the best to you, Sir!
StrikeEagle
Once you get it going, though it's the perfect pocket gun.
All the best to you, Sir!
StrikeEagle
Lord Bodak
Member
One thing I wish I had done before sending it back was to look at how far the firing pin protruded. Of course, they didn't adjust or replace the firing pin so what I see now should be the same as what I saw before. It definitely doesn't protrude as far as the firing pin on my GP-100, but that's all I can tell you. I don't have any other revolvers for comparison.
And as long as it fires without failures, I'm not gonna complain. But I would be interested to hear what everybody's headspace and pin protrusion are.
And as long as it fires without failures, I'm not gonna complain. But I would be interested to hear what everybody's headspace and pin protrusion are.
Lord Bodak
Member
Well, I took the repaired 642 to the range this morning. Fired 50 rounds, that's about all my hand could take. Round #25 had a light strike but it fired fine when I ran it through a second time. All the other functioned perfectly.
popeye
Member
None of my business. But since this gun is built for serious business, I think I'd have a gunsmith look at it. Some body with specs for firing pin protrusion on a Cententenial style pistol. Maybe somebody can send you some spent cases out of a 642 and you can eyeball them. Or somebody can feeler gauge their pin to cyl. space. My gauges seem to have gone A.W.O.L. or I'd check my 640 and .042.
Lord Bodak
Member
I agree, I'm still a little concerned about it. Like I said above, I'd be interested to hear some measurements from similar guns.
The primer strikes on the fired cases don't look shallow, they look about the same as spent casings from my GP-100 or my 1894C. But the one misfire was just like the ones before I sent it for repair, just a very light tap on the primer. Which makes me believe that it's not a firing pin length issue-- the firing pin can't be long enough to hit 49 rounds hard and somehow just nick the other one.
The primer strikes on the fired cases don't look shallow, they look about the same as spent casings from my GP-100 or my 1894C. But the one misfire was just like the ones before I sent it for repair, just a very light tap on the primer. Which makes me believe that it's not a firing pin length issue-- the firing pin can't be long enough to hit 49 rounds hard and somehow just nick the other one.
popeye
Member
O.K. If you swing out cyl. and unload gun, with cyl. still swung out you can push the cyl. release latch back and pull the trigger. Hold the trigger back, does firing pin wiggle? If not, only things I can think of is hammer face is not "true" and shifting sideways to a point not giving full firing pin motion (I know, Huh?) or something is in there occasionally impeding full hammer fall. If you send it back to S&W they may fix it but never tell the truth about the problem. I think you should pull the side plate and look around.
Lord Bodak
Member
I didn't know you could do that, thanks for the info (pushing the cylinder latch forward and pulling the trigger.
No firing pin wiggle. When I clean it I may pull the sideplate and look around. I don't know if it's worth sending back to S&W at this point, my intent is to put some more rounds through it and see what I see, at least for now.
No firing pin wiggle. When I clean it I may pull the sideplate and look around. I don't know if it's worth sending back to S&W at this point, my intent is to put some more rounds through it and see what I see, at least for now.
fiVe
Member
The dime test
Lord Bodak:
I pushed the cylinder latch forward then pulled and held the trigger. I placed a dime flat against the back plate and right next to the extended firing pin. The tip of the pin is just shy of the edge of the dime. How does yours compare?
Happy & safe shooting,
fiVe
Lord Bodak:
I pushed the cylinder latch forward then pulled and held the trigger. I placed a dime flat against the back plate and right next to the extended firing pin. The tip of the pin is just shy of the edge of the dime. How does yours compare?
Happy & safe shooting,
fiVe
Lord Bodak
Member
Wow. Nowhere near that far. Less than half the width of the dime!
I have an older 642-1 (ser#CCD65XX) which has never suffered from light primer strikes. I dry-fired it excessively when I first bought it and broke the firing pin. (S&W immediately replaced it and advised me to use snap caps from now on.)
I broke out the dial caliper and came up with 0.045" of firing pin protrusion, measured off of the opposing face of the forcing cone.
Hope this helps.
I broke out the dial caliper and came up with 0.045" of firing pin protrusion, measured off of the opposing face of the forcing cone.
Hope this helps.
Master Blaster
Member
I have one and I put about 1200 rounds through it to date and I have never had a failure to fire or a light strike all of my fired cases show a deep firing pin hit on the primer.
a 1 in 50 failure rate is completely unacceptable on any gun, let alone one designed specifically as a carry piece as this one is.
I would call and ask to speak to the service manager or even the president of the company.
If it were my 642 it would be going back to s&w pronto.
a 1 in 50 failure rate is completely unacceptable on any gun, let alone one designed specifically as a carry piece as this one is.
I would call and ask to speak to the service manager or even the president of the company.
If it were my 642 it would be going back to s&w pronto.
StrikeEagle
Member
- Joined
- Jul 8, 2004
- Messages
- 709
Hello, friend!
I feel your pain...
I carry a 642 in my pocket no matter what else I'm packin... normally a Colt Combat Commander. 5 rounds of WW LHP +p rounds should carry the day.
But...
Yours just ain't right.
Mine passes the Dime test... I just tried it. The pin pokes out just a hair short of the full dime thickness. I agree with the others here. Send it back. Make a firm phonecall to the biggest person you can reach in Customer Service. Be calm, intelligent and icy-firm. sigh
It's the greatest little pocket revolver on the planet... when it works. And yours just doesn't right now.
All the best to you; please let us know how this all shakes down.
StrikeEagle
I feel your pain...
I carry a 642 in my pocket no matter what else I'm packin... normally a Colt Combat Commander. 5 rounds of WW LHP +p rounds should carry the day.
But...
Yours just ain't right.
Mine passes the Dime test... I just tried it. The pin pokes out just a hair short of the full dime thickness. I agree with the others here. Send it back. Make a firm phonecall to the biggest person you can reach in Customer Service. Be calm, intelligent and icy-firm. sigh
It's the greatest little pocket revolver on the planet... when it works. And yours just doesn't right now.
All the best to you; please let us know how this all shakes down.
StrikeEagle
Lord Bodak
Member
Thanks everybody. I'm going to get in touch with S&W this week and see what it takes to get them to fix it. Taking it to the range last weekend made me fall in love with it-- the first range trip was so bad that I never got a feel for it, but now I'm hooked and I want it fixed so I can shoot it more!
fiVe
Member
Maybe the dime test can be a good "ballpark measurement" to help other 642 owners.
Lord B: Hang in there. Hopefully they will get it right this time. Please keep us in the loop!
R/fiVe
Lord B: Hang in there. Hopefully they will get it right this time. Please keep us in the loop!
R/fiVe
Lord Bodak
Member
Well, S&W says "send it in" so we'll see what happens. Going to FedEx it Monday morning.
Lord Bodak:
It used to be that you didn't have to send the gun in TWICE(!) because of the same issue. Times have sure changed.
Firing pin protrusion: Is something that can be tricky. If it's too short you get erratic or no ignition. If it is too long you can get punctured primers and escaping gas. Neither condition is good, although the former is more common.
In revolvers how deep the firing pin indents the primer is largely controlled by the headspace and mainspring tension. In guns with transfer bar safeties they can play a part, but S&W doesn’t use a transfer bar so that point is moot.
I don’t recommend checking firing pins with dimes, because a dime can vary in thickness. A set of automotive feeler gauges will do much better and doesn’t cost much. You can get a set at almost any hardware store or “Mart” automotive department.
Unload the revolver and use the gauges to determine the distance from the back of the cylinder to the breech face. Measure the distance behind each chamber, as it is possible the back of the cylinder isn’t square. Write down the answers.
Next, double-action the trigger, but don’t release the trigger. Then use the feeler gauges again to measure from the back of the cylinder to the tip of the protruding firing pin. Repeat this with each chamber and then write down the answers.
Now the next step should be done with a headspace gage, but you can use a fired – but deprimed case. Don’t use one with a fired primer because it could give you a false reading. Put the case in each chamber and use the feeler gauge to measure from the back of the case to the front of the breech face. This will give you the headspace. Write the answers down.
If you subtract the 2nd number from the 1st it will tell you how far the firing in is protruding. Then if you subtract the headspace (3rd answer) from the firing pin protrusion that will tell you how much the primer is indenting the primer (provided of course that the hammer spring can drive it full distance). If you have measured each chamber that will tell you if the cylinder is square and perpendicular to the breech face.
This will tell you a lot more then you can learn from a dime.
It used to be that you didn't have to send the gun in TWICE(!) because of the same issue. Times have sure changed.
Firing pin protrusion: Is something that can be tricky. If it's too short you get erratic or no ignition. If it is too long you can get punctured primers and escaping gas. Neither condition is good, although the former is more common.
In revolvers how deep the firing pin indents the primer is largely controlled by the headspace and mainspring tension. In guns with transfer bar safeties they can play a part, but S&W doesn’t use a transfer bar so that point is moot.
I don’t recommend checking firing pins with dimes, because a dime can vary in thickness. A set of automotive feeler gauges will do much better and doesn’t cost much. You can get a set at almost any hardware store or “Mart” automotive department.
Unload the revolver and use the gauges to determine the distance from the back of the cylinder to the breech face. Measure the distance behind each chamber, as it is possible the back of the cylinder isn’t square. Write down the answers.
Next, double-action the trigger, but don’t release the trigger. Then use the feeler gauges again to measure from the back of the cylinder to the tip of the protruding firing pin. Repeat this with each chamber and then write down the answers.
Now the next step should be done with a headspace gage, but you can use a fired – but deprimed case. Don’t use one with a fired primer because it could give you a false reading. Put the case in each chamber and use the feeler gauge to measure from the back of the case to the front of the breech face. This will give you the headspace. Write the answers down.
If you subtract the 2nd number from the 1st it will tell you how far the firing in is protruding. Then if you subtract the headspace (3rd answer) from the firing pin protrusion that will tell you how much the primer is indenting the primer (provided of course that the hammer spring can drive it full distance). If you have measured each chamber that will tell you if the cylinder is square and perpendicular to the breech face.
This will tell you a lot more then you can learn from a dime.
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