Light primer strikes S&W 625

Patriot

Patriot

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I took my 625 to the range today with my freshly loaded .45AR bullets and was tearing
up the targets big time. Only problem was that I was getting some light strikes on the
primers occasionally and when that happened the round wasn't firing. Since the gun was
dead on I continued until, SQUIB @!#$^&**((*__+_++|!!!! I couldn't get it out so that
put the kibosh on continuing to shoot the 625. As I was attempting to remove the squib,
the yoke and cylinder came off the gun. Seems the yoke screw had backed out (S&W
obviously believes that this doesn't need to be a locking type screw for some reason).

My question is: Do you think that the yoke screw being loose (and subsequently the yoke
and cylinder) could contribute to the light primer strikes? BTW, this happened when I was
shooting .45ACP with moonclips as well. I expected that the cause of it was the moonclips
but I guess not. I looked at the gun after I removed the squib at home and the firing pin
seems to function fine.
 
Last edited:
The Boston Patriot said:
My question is: Do you think that the yoke screw being loose (and subsequently the yoke
and cylinder) could contribute to the light primer strikes? BTW, this happened when I was
shooting .45ACP with moonclips as well. I expected that the cause of it was the moonclips
but I guess not. I looked at the gun after I removed the squib at home and the firing pin
seems to function fine.
Click to expand...

IF - again, IF - the loose screw allowed the cylinder to move forward, it would reduce the impact of the firing pin on the primer.

Seems unlikely, however.
 
I have the same problem with my 625. A lot of guys like to run the model 625 with that screw backed out a little to get a smoother trigger pull.

When I got mine the screw was loosened up alot by the first owner and it had light primer hits every time I used it.

I don't like to tighten it down firmly because it makes such a difference in the pull. Now when I get a light primer hit I take the grips off and just tighten it.
 
The Boston Patriot said:
I took my 625 to the range today with my freshly loaded .45AR bullets and was tearing
up the targets big time. Only problem was that I was getting some light strikes on the
primers occasionally and when that happened the round wasn't firing. Since the gun was
dead on I continued until, SQUIB @!#$^&**((*__+_++|!!!! I couldn't get it out so that
put the kibosh on continuing to shoot the 625. As I was attempting to remove the squib,
the yoke and cylinder came off the gun. Seems the yoke screw had backed out (S&W
obviously believes that this doesn't need to be a locking type screw for some reason).

My question is: Do you think that the yoke screw being loose (and subsequently the yoke
and cylinder) could contribute to the light primer strikes? BTW, this happened when I was
shooting .45ACP with moonclips as well. I expected that the cause of it was the moonclips
but I guess not. I looked at the gun after I removed the squib at home and the firing pin
seems to function fine.
Click to expand...

Questions: 1.Which 625 do you have?

2.Is this the first time you fired the gun?

3.Do the rounds ignite on the second strike?

4.Did you check the screw prior to shooting?

5.What method did you use to clear the squib?

6. Was the gun purchased new by you?

7. If 6 is no did the previous owner have
action work performed?

8. If 6 is YES did you have action work
performed? (By who)

Comments:
If it is the newer style 625 with frame mounted firing pin, a loose yoke screw would make little to no difference. They are a spring tensioned fit and not a true fit like the older guns were. As a rule, a loose yoke screw will produce End Shake in the Yoke. The spring loaded side plate screw nearly eliminated that. End shake Yoke would rarely cause a light strike. End Shake Cylinder will almost always cause intermittent light strikes but that is not caused by a loose screw.

If it is a loose "Strain" screw, different story. That will give you light strikes.

If this is not your first time shooting the gun see question 4. In 27 years as a S&W trained Armorer, I have rarely seen a properly tightened yoke screw loosen and I shoot a lot of rounds through a revolver. In over 75 years of the same design, wouldn't you think if S&W saw a need for a locking screw they would have done it? The screw holds the yoke but has other functions that make it an impossible task with a locking screw. You need to check all screws on the gun (Including sight screws) prior to heading to the range. It is kind of like the circle check on a truck [wink]

If the rounds went off on the second strike, I would suspect you had high primers. Very common.

If the 625 is new style, the yoke screw is spring loaded. When clearing the squib, if you exerted pressure on the cylinder toward the muzzle, you could push the yoke button past the spring loaded insert and cause the cylinder to fall off. I always suggest removing the cylinder and yoke to clear a squib. Makes the gun easier to hold and there is less chance of damaging several parts associated with the cylinder (Bent extractor rod is very common)

My questions on the action work are for the light strikes. I have seen work (and repaired it) from a competent pistol smith that is not up to standards as far as revolvers go. The work produced light strikes. I have also seen a lot of kitchen table gunsmiths that try action work only to cause problems.

Edit to add to Bugs100: I have never heard of anyone running a backed out yoke screw for any reason. Strain screw yes, Yoke screw NO

Hope this helps,

Gary
 
Last edited:
MassMark said:
Gee whiz Gary...I think you may have some experience with these things. [wink] I don't even own a 625, but really enjoyed reading that post - great information! [cheers]
Click to expand...

mark056 said:
Great post Gary...

Question for the OP: are you the original owner of the 625 in question?

Mark L.
Click to expand...

Thanks, I try [wink]

Mark L see my question #6 [smile]
 
I was refering to the Strain screw and never gave it a thought that some one would think I was writting about the yoke screw, I'm sorry I should have made that more clear.
 
Round Gun Shooter said:
Questions:
1.Which 625 do you have?
Click to expand...
625-4, 5 inch barrel, CBCxxxx.
2.Is this the first time you fired the gun?
Click to expand...
No. I have fired it two or three times before. The first time I fired it was the only time
I didn't have any problem with light strikes. I was shooting factory fodder w/.45ACP and
moonclips at that time. Next time I went shooting, exactly the same scenario but started
having the light strikes.
3.Do the rounds ignite on the second strike?
Click to expand...
Yes, most of the time, maybe all of the time. It's hard to completely ascertain as the
light strikes are happening two or three times a cylinder and in random cylinder positions.
4.Did you check the screw prior to shooting?
Click to expand...
No. I just noticed right after I got the squib round and went to clear it and the cylinder
and yoke came out as I turned the gun barrel up to see where the round had settled.
5.What method did you use to clear the squib?
Click to expand...
I inserted a shaft in the front end of the barrel and applied judicious force after lubing
heavily with mystery oil. It was a LRN so I centered the shaft on the round, (taped the
shaft) and holding the gun in my left hand used a rubber mallet to drive it towards the
cylinder.
6. Was the gun purchased new by you?
Click to expand...
No. I purchased this this past year. It came with a bent extractor shaft. It has been
returned to S&W twice since I owned it. Virtually everything external, including frame, has
been replaced by S&W with new parts. I would venture that none of the internal parts were
replaced since that is not what I returned it for.
7. If 6 is no did the previous owner have action work performed?
Click to expand...
See #6. I cannot be sure but it is a nice smooth trigger and it is about 8-9 pounds.
8. If 6 is YES did you have action work performed? (By who)
Click to expand...
I have not had any work other than returning it to S&W for warranty work.
Comments:
If it is the newer style 625 with frame mounted firing pin, a loose yoke screw would make little to no difference. They are a spring tensioned fit and not a true fit like the older guns were. As a rule, a loose yoke screw will produce End Shake in the Yoke. The spring loaded side plate screw nearly eliminated that. End shake Yoke would rarely cause a light strike. End Shake Cylinder will almost always cause intermittent light strikes but that is not caused by a loose screw.

If it is a loose "Strain" screw, different story. That will give you light strikes.

If this is not your first time shooting the gun see question 4. In 27 years as a S&W trained Armorer, I have rarely seen a properly tightened yoke screw loosen and I shoot a lot of rounds through a revolver. In over 75 years of the same design, wouldn't you think if S&W saw a need for a locking screw they would have done it?
Click to expand...

Good point! I might apply some locktite to it though.[smile]

The screw holds the yoke but has other functions that make it an impossible task with a locking screw. You need to check all screws on the gun (Including sight screws) prior to heading to the range. It is kind of like the circle check on a truck [wink]
Click to expand...
Another good point, something which I rarely do and should make it a habit.
If the rounds went off on the second strike, I would suspect you had high primers. Very common.
Click to expand...

I thought of that and I am using mil brass reloads(ACP) but this happened on factory ACP ammo
and AR loads (first loading with Starline Brass) as well. I checked all of the rounds that had the
light strikes and the primers appear to be seated normally. Of course .010" may be stretching it
for these old eyes to differentiate! [smile]

If the 625 is new style, the yoke screw is spring loaded. When clearing the squib, if you exerted pressure on the cylinder toward the muzzle, you could push the yoke button past the spring loaded insert and cause the cylinder to fall off. I always suggest removing the cylinder and yoke to clear a squib. Makes the gun easier to hold and there is less chance of damaging several parts associated with the cylinder (Bent extractor rod is very common)

My questions on the action work are for the light strikes. I have seen work (and repaired it) from a competent pistol smith that is not up to standards as far as revolvers go. The work produced light strikes. I have also seen a lot of kitchen table gunsmiths that try action work only to cause problems.

Edit to add to Bugs100: I have never heard of anyone running a backed out yoke screw for any reason. Strain screw yes, Yoke screw NO

Hope this helps,

Gary
Click to expand...
It does. Thanks a lot Gary. When I removed the squib I opened the cylinder and held the gun
in my hand by the frame so I am pretty sure that I didn't damage anything in the process.
 
Last edited:
what primers on the reloads? - CCI are hardest- WIN are softest. this may be your source. Gary covered all the other issues very well.
 
For revolver reloads, you will be best to make sure primers are fully set. I have been accused of crushing my primers but I don't get misfires. I also use nothing but Federal Primers which are the softest. Hard to get, but with the 6# double action triggers I have they are necessary.

They have said the new Win are softer also but I am not about to try.

As far as high primers on factory loads, I have had them so don't rule it out if they go bang the second time. That is the joy of a revolver and a Sig. The double strike capability is a real plus.

Pull the grips and check the strain screw. Most likely it has backed out. Stay away from LocTite. Use fingernail polish. People think I am joking when I post this but it is all I use on revolver screws. It works.

And Bugs, I knew what you meant, but others may have been confused which is why I posted the comment.

As an aside, those turning out a strain screw to lighten a revolver action can cause other problems. I truly feel the springs need to be adjusted and mated with the rebound spring to get a proper trigger pull. Smith & Wesson will caution you about Knuckling but I will leave that for another lesson [grin]

Gary

PS: Greg, get back to the bench and off the computer [rofl][rofl][rofl]
 
Round Gun Shooter said:
For revolver reloads, you will be best to make sure primers are fully set. I have been accused of crushing my primers but I don't get misfires. I also use nothing but Federal Primers which are the softest. Hard to get, but with the 6# double action triggers I have they are necessary.

They have said the new Win are softer also but I am not about to try.

As far as high primers on factory loads, I have had them so don't rule it out if they go bang the second time. That is the joy of a revolver and a Sig. The double strike capability is a real plus.

Pull the grips and check the strain screw. Most likely it has backed out. Stay away from LocTite. Use fingernail polish. People think I am joking when I post this but it is all I use on revolver screws. It works.

And Bugs, I knew what you meant, but others may have been confused which is why I posted the comment.

As an aside, those turning out a strain screw to lighten a revolver action can cause other problems. I truly feel the springs need to be adjusted and mated with the rebound spring to get a proper trigger pull. Smith & Wesson will caution you about Knuckling but I will leave that for another lesson [grin]

Gary

PS: Greg, get back to the bench and off the computer [rofl][rofl][rofl]
Click to expand...

Gary,

I can't thank you enough for all your input. Is there any adjustment to the strain screw or
is it one of those all the way (in or out)?

Regards,

Richard
 
The Boston Patriot said:
Gary,

I can't thank you enough for all your input. Is there any adjustment to the strain screw or
is it one of those all the way (in or out)?

Regards,

Richard
Click to expand...

It should be tight all the way. If it is and you still get light strikes, take the screw out, measure it with a caliper and tell me what it is. I can fix one a hair longer for you.

Gary
 
I checked the strain screw. It was backed off by about a turn. When I screwed it back in
(bottomed) it increased the trigger pull from about 8.5-9 Lbs to about 10-10.5 Lbs. My scale
only goes up to 10 pounds and it was slightly over the top of the scale so I am guessing
somewhat.
 
Scrivener said:
IF - again, IF - the loose screw allowed the cylinder to move forward, it would reduce the impact of the firing pin on the primer.

Seems unlikely, however.
Click to expand...

The screw in question has no function or effect on the fore-and-aft position of the cylinder when the cylinder is "closed."
 
The Boston Patriot said:
I checked the strain screw. It was backed off by about a turn. When I screwed it back in
(bottomed) it increased the trigger pull from about 8.5-9 Lbs to about 10-10.5 Lbs. My scale
only goes up to 10 pounds and it was slightly over the top of the scale so I am guessing
somewhat.
Click to expand...

Light strike problem solved [wink]
 
Do any of you guys loctite those screws? (eg use weak loctite). I have a few friends who are always futzing with that screw because it seems to back out after awhile. I don't know what S+W did to the one on my 686, but mine never backs itself out.

-Mike
 
drgrant said:
Do any of you guys loctite those screws? (eg use weak loctite). I have a few friends who are always futzing with that screw because it seems to back out after awhile. I don't know what S+W did to the one on my 686, but mine never backs itself out.

-Mike
Click to expand...

I'm going to take RGS's advice and use some nail polish (clear) on them. I used some
locktite on a particularly troublesome frame screw on my Ruger SBHH which kept backing
out and it has held fine for at least a couple of hundred rounds of different varieties. It
was the weak locktite (blue). I also have some grip screws on my 1911 that need to be
treated and I was going to give the nail polish a shot there as well.

I'm not going to treat the strain screw on the 625 as I'm pretty sure I received it that
way. If not, I will try the nail polish on that as well.
 
drgrant said:
Do any of you guys loctite those screws? (eg use weak loctite). I have a few friends who are always futzing with that screw because it seems to back out after awhile. I don't know what S+W did to the one on my 686, but mine never backs itself out.

-Mike
Click to expand...

They used the proper size screw driver and tightened the screw.[wink]
 
Actually, there was a time (mid-80s I think but don't hold me to that) when S&W did have a problem with these screws backing out.

It turned out that the screw was a bit too long. As a result, the tip of the screw bottomed out and torqued up by contacting the nose of the screw on the groove in the yoke pin, whereas the screw is intented to torque on the underside of the head, with the tip (in the yoke pin groove) contacting nothing. Where this happened, the action of opening and closing the cylinder worked on the screw and eventually caused it to back out. The solution was to take just enough off the tip of the screw as to prevent it from bottoming out.
 
RKG said:
Actually, there was a time (mid-80s I think but don't hold me to that) when S&W did have a problem with these screws backing out.

It turned out that the screw was a bit too long. As a result, the tip of the screw bottomed out and torqued up by contacting the nose of the screw on the groove in the yoke pin...
Click to expand...

Wrong screw. They're talking about the strain screw backing out.

I've never had it happen, but I do what RGS recommends.
 
Round Gun Shooter said:
Light strike problem solved [wink]
Click to expand...

Definitely solved. I took the gun to the range today and all those light strike rounds
fired with one exception. It took two strikes to fire that particular round. I might have
had something to do with where the firing pin stuck that already dented primer the first
time as it fired the second time. None of my other rounds with unfired primers had any
problems.

Thanks again RGS. I went out and purchased some clear nail polish today to put a dab
on the strain screw (belt and suspenders) just in case.

TBP
 

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