Failure To Fire

[K-22]

I have a 625 chambered in .45ACP.
The gun had the hammer mounted firing pin.
I use full moonclips.
The gun has had an action job done at S&W.

I have shot this gun for hundreds of rounds, without any problems.

In the last couple of outings, I have experienced a couple of failure to fire issues. I am shooting factory (UMC Yellow Box, and the Federal with the small primers) ammo. on the rounds that have failed to fire, the primer strikes appeared to be very light.
I recently introduced some new moonclips into the program so I have enough to load up before plate matches.
Due to the fact the moons are the only thing that have changed, I would think they might be the issue.

I am open to your thoughts, ideas, and potential remedies.


Best,
Gary

 

[shawn mccarver]

I have a 625 chambered in .45ACP.
The gun had the hammer mounted firing pin.
I use full moonclips.
The gun has had an action job done at S&W.

I have shot this gun for hundreds of rounds, without any problems.

In the last couple of outings, I have experienced a couple of failure to fire issues. I am shooting factory (UMC Yellow Box, and the Federal with the small primers) ammo. on the rounds that have failed to fire, the primer strikes appeared to be very light.
I recently introduced some new moonclips into the program so I have enough to load up before plate matches.
Due to the fact the moons are the only thing that have changed, I would think they might be the issue.

I am open to your thoughts, ideas, and potential remedies.


Best,
Gary

After making sure your strain screw has NOT been shortened, make sure your strain screw is tightened ALL THE WAY DOWN.

Then, make sure your moon clips are the right thickness and that they are ABSOLUTELY flat. The least bit of variance can create a scenario where a light hit combined with a cartridge that can go a tiny fraction forward upon firing pin impact will result in insufficient firing pin energy transferred to the primer, resulting in a failure to fire.

If you are using reloads, you should use Federal primers and they must be ABSOLUTELY fully seated into pristine primer pockets.

The .45 revolver with moon clips is a fantastic instrument, but there is a reason they are supplied with HEAVY actions to insure that the firing pin packs a wallop* when it strikes the primer.

*A heavy blow or punch.

 

[scooter123]

Shawn has made some excellent suggestions. Ignition problems are nearly ALWAYS a result of the strain screw backing out and reducing the tension of hte mainspring. I can also say that from what I have seen coming out of the Performance Center is that they are NOT hand fitting the strain screws to lighten the trigger pull, they just apply a small dab of thread locker and leave the screw set a bit loose. IMO this is a near guarantee that the strain screw will shoot "looser" in any revolver that sees some use. IMO it's wiser to tighten them down completely and leave them fully tightened. If you want a lighter trigger and can actually limit yourself to only Federal ammunition then use a file to fit the strain screw for a lighter trigger. However, it's a good idea to have a spare on hand just in case you go a bit too far.

BTW, from recent shooting this is my sequence of primer "hardnesses" from lightest to heaviest. Federal, CCI, Winchester, Remington, Sellier & Belloit, and way way to the hard side is the CCI lead free Clean Fire primers and ammunitions.

 

[tomcatt51]

I recently introduced some new moonclips into the program so I have enough to load up before plate matches.
Due to the fact the moons are the only thing that have changed, I would think they might be the issue.

Are your new moonclips the (Rimz I think) plastic ones?

 

[garbler]

I went through this evolution with a first series 625 back in the late 80's a gun that was replaced by the factory twice. But unless somebody has tuned the gun and set up the strain screw I doubt this is the source of your problem by itself.

You have to realize that with moon clips the case is now head spacing on the clip thickness. Are moon clips the same —no in fact some wouldn't hardly work at all years ago. Anyway they are of different thicknesses some are springier than others and in the final analysis they can react to the hammer blow and rob the hammer nose of proper impact with the primer. I think they have improved a lot but I still hear about this problem all the time.

If you put 45 auto rims in that gun I will bet it fires perfectly. You can check the headspace on the gun if you want but I doubt that is the problem either. The problem is the moon clips and the thickness variable which may be standard now I don't know but also the way the clip retains the case head in the extractor groove. They have to make it loose enough to be able to load and strip and therein, I believe anyway, is where the play comes in.

Caveat: If the gun won't shoot auto rims then you have a light hammer. You need to measure it with a trigger pull gauge but I am away from my notes and don't recall the oz or pounds needed. I posted it here once before if you can find it. And with the new moon clip tools out there now that I have never used it may be they can load and strip them with really tight uniform clips but I really think you need to concentrate on the moon clips.

regards

 

[K-22]

After making sure your strain screw has NOT been shortened, make sure your strain screw is tightened ALL THE WAY DOWN.

Then, make sure your moon clips are the right thickness and that they are ABSOLUTELY flat. The least bit of variance can create a scenario where a light hit combined with a cartridge that can go a tiny fraction forward upon firing pin impact will result in insufficient firing pin energy transferred to the primer, resulting in a failure to fire.

If you are using reloads, you should use Federal primers and they must be ABSOLUTELY fully seated into pristine primer pockets.

The .45 revolver with moon clips is a fantastic instrument, but there is a reason they are supplied with HEAVY actions to insure that the firing pin packs a wallop* when it strikes the primer.

*A heavy blow or punch.

The action was not lightened to any degree, but it is really smooth. The strain screw is all the way in, and it is tight. Since the action job, I had fired a thousand or so rounds without a hitch.
Right now, my main suspect would be the new (steel) moonclips (I think just one clip may be the culprit). I will check them for flatness on a small sheet of plate glass. In the event I discover any that are not flat, how do I flatten them, or should I just toss it?
Thank you for your thoughts and Ideas.

Best,
Gary

 

[scooter123]

If you have a moon clip that you know is causing problems I would advise tossing it into the trash. Moon clips are made from spring tempered steel and this material has a distinct tendency to resist small amounts of bend. This means that if you have to tweak it just a little bit you'll find it quite difficult to get it right, you'll either over bend it or it will spring back with no apparent change.

 

[tomcatt51]

I will check them for flatness on a small sheet of plate glass.

Just stack your clips, gaps all lined up. Any bent ones will be obvious. Ranch Products makes good moonclips. Ranch Products You have to call them.

 

[K-22]

Thanks for the replies. It would appear that a couple of bent moon clips were the issue.

Best,
Gary