Two 625s Fail To Fire. Need Help.

[Stu1205]

I need some help with a FTF problem.
I went to the range yesterday with two new to me 625s.
One is a 625-2 5" bbl and the other is a 625-10 2.1" bbl.

Both are chambered for .45 ACP. I know that the chambers in
the cylinder are stepped to allow shooting without moon clips,
however when I tried to shoot both guns, I was getting light
primer strikes. One or two chambers would fire, but on the rest,
the firing pin just dimpled the primer. I tried this with
three different brands or ammo, so I know that that is not the problem.

When I got home I tried the pen test on both guns.
I cocked the gun, inserted a pen into the barrel, and pulled the trigger.
The pen shot up to the ceiling on all 6 chambers of both guns.
I examined the space between the back of the cylinder and the
strike plate (?) and it seems that there is too much space for
the firing pin to hit the primer.
Do you think that using moon clips would take up some of the
space and fix this problem?

Is there any other way to lessen the space behind the cylinder?
I don't shoot these in competition, so I don't need to empty the
cylinder and reload quickly, and I really would prefer to shoot
these guns without moon clips.

Any help or advice would be appreciated.

Thanks,
Stu

 

[Jim Watson]

This is not an unknown condition for the 625s.

If you handload or are very patient shopping for ammo, you can shoot .45 Auto Rim.

If you want to shoot .45 ACP with the least bother, you can get the plastic Rimz clips which are easy to load and unload barehanded.
Ez Moon Clips

 

[*chris*]

Are you really sure you are supposed to shoot without moonclips? 45ACP moonclips are really thick and add quite a bit of support. The mere hassle of removing the brass makes me shoot with moonclips all the time anyway.

You may want to see if the strain screw was backed out for a bubba trigger job. furthermore, those stainless steel strain screws tend to peen over and shorten.

Good luck, some things to check.

Chris

 

[jrd1976]

Check the strain screw. It should be tight.
If someone has filed it off, you should replace it.
If you cannot find one, put a spent primer cap over it, and retighten it.

If you have the hammer nose firing pin, make sure the window opening is clean.

If you have the frame mounted firing pin, make sure the channel is clean and lubricated.

Have you removed the sideplate and checked for grease or old oil?
Are there scratches on the hammer, showing it is rubbing the frame?

 

[n64atlas]

When you are loading the rounds, are you pushing them in tight? You might be forcing them past the chamber ridge. Are you shooting reloads that the cases have been trimmed too short? 45 ACP headspaces on the case mouth. You only lightly taper crimp these cases. Too much crimp or role crimp will change headspace.

 

[Pizza Bob]

You are correct in assuming the shoulder in the chamber is there for headspacing purposes. However, since SAAMI sets the specs for cartridge dimensions, the shoulder is placed at maximum case length depth for a given caliber. My experience has been that any factory ammo or brass, when new, is always considerably less than this dimension - meaning that, in reality, headspacing on that shoulder, by the case mouth, seldom actually occurs.

What does happen is that variances in chamber roundness, smoothness, cleanliness and other variables, will hold some cartridges firmly enough that a firing pin strike will ignite the primers. Others are driven forward in the chamber, which results in a light primer strike and a failure to ignite.

Just as some rounds are held tightly enough for ignition and others are driven forward, some cases may drop out of the cylinder from gravity, while others may be "pluckable" and yet others will have to be poked out using a rod.

You should consider moon clips essential for any revolver that is chambered for a rimless or semi-rimmed round. The other alternative is using the rimmed version of that round, if one exists.

Adios,

Pizza Bob

 

[Stu1205]

I am only using factory ammo. Winchester, Remington and Federal.
The 625-2 has a hammer mounted firing pin, and the 625-10
has a frame mounted firing pin.
I inspected the screws on the side plate. There is no evidence of
a screwdriver ever being in there, so I am confident that nobody
went in and did a bubba trigger job.
The guns are oiled properly and the firing pin holes are clean.
The strain screw is tight too.

Stu

 

[birdshooter]

I think you would best be served by using ACP brass in moonclips or Auto Rim brass. With moonclips and a tight strain screw I doubt you will have a problem.

 

[colt_saa]

I need some help with a FTF problem.
I went to the range yesterday with two new to me 625s.
One is a 625-2 5" bbl and the other is a 625-10 2.1" bbl.

Both are chambered for .45 ACP. I know that the chambers in
the cylinder are stepped to allow shooting without moon clips

This is not a TRUE fact. This is an INTERNET Urban Legend

Those "steps" are not there with the designer's intention of allowing the case mouth to rest on them putting the cartridge in a position of proper headspace.

Those "steps" are the cylinder throats. They make the hole in the cylinder smaller so that the projectiles do not rattle back and forth as they travel toward the forcing cone.

It is by coincidence that a large portion of these revolvers will fire without moonclips, it is not by design

With the exception of the 547, Smith and Wesson revolvers designed by the factory to fire rimless ammunition, headspace on the moonclips.

Put your ammunition in moonclips and try again before anything else.

 

[Kernel Crittenden]

Is there any other way to lessen the space behind the cylinder?

You can install endshake bearings (also called cylinder shims). Assuming you have excessive endshake. This will push the cylinder back. By reducing the front-to-back "play", it also increases the barrel-cylinder gap. So there's a trade off. I don't think this is what you need to solve your problem, however. I would listen to colt-saa's advice.

S&W K L N Shim Kit

Barrel-Cylinder Gap and Endshake

The gap between the back of the barrel and the front of the cylinder is known as the Barrel-Cylinder (B-C) gap. The Front-To-Back Movement of the Cylinder is the Endshake. In order to properly measure these clearances you will need a Feeler Gauge Set. K-D Tools USA Made # 161 Deluxe Feeler Gauge is available all over the internet and at most good auto parts stores for under $10.

To check B-C gap, hold the cylinder rearward and insert the (thickest that will fit) feeler between the Barrel and the Cylinder, this is your Barrel-Cylinder Gap, write it down, it should be between .004" and .008" Next, hold the cylinder forward and re-check the gap, write it down. There may be no clearance here at all, the cylinder may touch.

The difference between the two numbers is the amount of movement or Endshake your cylinder has, it should be between .001" and .004" on most Double Action Revolvers, manufacturers clearances may vary. Cylinder Shims can be used to adjust your B-C Gap and Endshake. Available in the following thicknesses; .002", .003", .004", .005", .006", .007", 008" and .009"

 

[JAREDSHS]

This is not a TRUE fact. This is an INTERNET Urban Legend

Those "steps" are not there with the designer's intention of allowing the case mouth to rest on them putting the cartridge in a position of proper headspace.

Those "steps" are the cylinder throats. They make the hole in the cylinder smaller so that the projectiles do not rattle back and forth as they travel toward the forcing cone.

It is by coincidence that a large portion of these revolvers will fire without moonclips, it is not by design

With the exception of the 547, Smith and Wesson revolvers designed by the factory to fire rimless ammunition, headspace on the moonclips.

Put your ammunition in moonclips and try again before anything else.

COLTSAA has nailed it. Just get out the moon clips and use them , That's the way the gun was designed.

 

[Stu1205]

This is not a TRUE fact. This is an INTERNET Urban Legend

Those "steps" are not there with the designer's intention of allowing the case mouth to rest on them putting the cartridge in a position of proper headspace.

Those "steps" are the cylinder throats. They make the hole in the cylinder smaller so that the projectiles do not rattle back and forth as they travel toward the forcing cone.

It is by coincidence that a large portion of these revolvers will fire without moonclips, it is not by design

With the exception of the 547, Smith and Wesson revolvers designed by the factory to fire rimless ammunition, headspace on the moonclips.

Put your ammunition in moonclips and try again before anything else.

Thanks for that info. I did not know that. I have been shooting
for over 35 years, and while I have many revolvers, none of
them are chambered for .45 ACP. I have about 20 moonclips.
I will head back to the range next week and report back.

Stu

 

[Stu1205]

Thank you also to everybody else for your help and input.

Stu

 

[H Richard]

I have a Model 25-2 and a 1917, and both will fire reliably without moon clips. Is the factory ammo you are using taper-crimped? if so measure the case just behind the bullet. What does it measure? If it measures less than about .467 - .468 it may be slipping past the shoulder and seating too deep. How does it do with using moon clips? That is the whole advantage of that revolver anyway. With a proper moon clip tool it is no problem loading and unloading moon clips.

 

[theoneff]

With a gun cut for clips why not just use them. They are fun fast and keep your brass all together. Get a good loading tool and buy 100 and you got a great range sesson ready to go

 

[one eye joe]

I WOULD HAVE A QUALIFIED 'SMITH CHECK THE B/C GAP, AND THE ENDSHAKE. I HAVE A 625, MODEL OF 1989 WHICH SHOOTS ANY KIND OF .45ACP INCLUDING RELOADS, WITHOUT MOON CLIPS. MOON CLIPS WILL CERTAINLY CORRECT YOUR ISSUE--WHICH IMHO IS MERELY A SYMPTOM OF AN UNDERLYING PROBLEM…...

 

[fkienast]

Check the strain screws first!

 

[Jim Watson]

Pizza Bob describes the situation.
It seems that the later stainless guns are more prone to maximum length chambers and misfires with minimum length cartridges than the old blue guns. One eye joe got lucky.

As I said, the Rimz clips are easy to use.

 

[45Wheelgun]

I seem to remember that there was a specific "Dash Number" where S&W specifically dropped support for 45acp rounds not using a moonclip?

Even if that is just "internet lore", it still would have been after the 625-2. I have a 625-3 that will fire 45acp without using moonclips. I agree with the above posts - start with the strain screw.

The 625-10 would have been after the change if internet lore is to be believed.

Because I am a kind hearted guy who feels bad that your modern 625 isn't as good as your older one and that will force you to use those expensive moonclips and equally expensive specialty loading tool ...I will be happy to take it off your hands for a fair price...

 

[Stu1205]

Because I am a kind hearted guy who feels bad that your modern 625 isn't as good as your older one and that will force you to use those expensive moonclips and equally expensive specialty loading tool ...I will be happy to take it off your hands for a fair price...

Thanks, Dave. You're the best.

Stu