625 misfires/45 auto rim

[DocSavage]

Been having problems with misfires in my 2 625s with 45 auto rim R-P brass. Primers seated correctly CCI large pistol,was getting 2 - 3 ftf out of 6 rounds.
I was having this problem with one pistol so I brought my other 625 same thing. After some poking around found out that the primer pockets could be shallow. So I deprived some of cases measured pocket depth .117-.118".
So bought a primer pocket uniformed and corrected the problem.
I've some ammo loaded in Starline brass that I'll try later.

[Mk42gunner]

????

Most of the misfires I have heard about in S&W Model 25/625 revolvers has supposedly been traced to the springiness of the half or full moon clips for using .45 ACP ammo. In theory, .45 AR brass doesn't have this problem, but obviously yours do.

I would think deepening the primer pockets would make the situation worse, not better.

I would check your strain screw for tightness, for some reason people like to loosen them instead of doing a real trigger job. I would also check headspace of all chambers on both guns.

For the record, the Model 25-2 that I had 30 thirty years ago never had a misfire with anything--clipped or not, factory hardball or reloads; all ACP, AR wasn't all that easy to find then.

Robert

[DocSavage]

????

Most of the misfires I have heard about in S&W Model 25/625 revolvers has supposedly been traced to the springiness of the half or full moon clips for using .45 ACP ammo. In theory, .45 AR brass doesn't have this problem, but obviously yours do.

I would think deepening the primer pockets would make the situation worse, not better.

I would check your strain screw for tightness, for some reason people like to loosen them instead of doing a real trigger job. I would also check headspace of all chambers on both guns.

For the record, the Model 25-2 that I had 30 thirty years ago never had a misfire with anything--clipped or not, factory hardball or reloads; all ACP, AR wasn't all that easy to find then.

Robert

One of the first thing I checked was the strain screw and it was tight.
Didn't have the same problem with 45 auto in full moon clips in either revolver.

[Dan Cash]

Like MK42, I had a very nice 25 back in the 80s that handled clipped, un clipped and auto rim with 100 percent reliability. Only problem is the revolver would not hit a barn door at a hundred yards. Beautiful gun went down the road. If I had known then what I know now. Doug Guy and Accurate Molds would have fixed the problem.

[tejano]

Here is mine.
303294
It did have a professional trigger job and was set up for federal primers. It was never quite 100% with either AR brass or moon clips, but it was good. This lasted for 20 years or so until recently when it started being about 80% reliable even with Federal primers. A local gunsmith looked it over and replaced the mainspring. That didn’t fix it. He finally concluded that the bobbed hammer was the most likely cause. He had an old target style hammer in his miscellaneous box so he put it on. Fired 80 AR rounds yesterday and all but one went bang. We will see how it goes. However I will also note that I never have cleaned the primer pockets. I will do that when I next reload for it.

[Jtarm]

If they’re PC guns, the lighter mainspring requires soft primers, in my experience.

Also check you’re strain screws.

Also an Apex extended firing pin might give a little more oomph.

[megasupermagnum]

Here is mine.
303294
It did have a professional trigger job and was set up for federal primers. It was never quite 100% with either AR brass or moon clips, but it was good. This lasted for 20 years or so until recently when it started being about 80% reliable even with Federal primers. A local gunsmith looked it over and replaced the mainspring. That didn’t fix it. He finally concluded that the bobbed hammer was the most likely cause. He had an old target style hammer in his miscellaneous box so he put it on. Fired 80 AR rounds yesterday and all but one went bang. We will see how it goes. However I will also note that I never have cleaned the primer pockets. I will do that when I next reload for it.

That makes no sense. A bobbed hammer should set primers off better, not worse. Skeletonized hammers are the best of the best for lock time and reliability. If that gun has the separate firing pin, make sure that is clean.

[M-Tecs]

Some good discussion that might help here

https://forums.brianenos.com/topic/293297-question-about-bobbed-hammers/

https://forums.brianenos.com/topic/163567-bobbing-hammer-spur/

[Eddie Southgate]

Deprimed

[slughammer]

..... After some poking around found out that the primer pockets could be shallow. So I deprived some of cases measured pocket depth .117-.118".
So bought a primer pocket uniformed and corrected the problem.....

So you fixed the problem by uniforming the pockets?

I wonder if the discrepancies in the pockets were causing an issue with the anvil not being supported? Did the tool perhaps take out a small shelf or fat radius at the bottom of the pocket?

Sent from my SM-G781U using Tapatalk

[DocSavage]

The depth of the pockets are now .122" and any built up residue has been removed as well. There was a fair amount of shavings from the uniforming as well. Not going to reload all 100 just 20 random cases if the problem still persists off to a gunsmith for repairs.

[pworley1]

Let us know how those worked.

[Jtarm]

That makes no sense. A bobbed hammer should set primers off better, not worse. Skeletonized hammers are the best of the best for lock time and reliability. If that gun has the separate firing pin, make sure that is clean.

^^^^^^^^^^

[DocSavage]

Let us know how those worked.

Going to the range on Friday. The failure to fire is happening with 2 different 625s that's why I think it's the R-P brass. Don't recall having this problem with 45 acp in moon clips or Starline auto rim brass.

[slughammer]

Feeler gages and caliper.

You could measure the gap between the brass and the frame with feeler gages. Measure both moon clipped 45acp and the autorim.

The rim thickness on the autorim should be the same as the sum of the acp rim plus the moon clip thickness.

If the autorim-rims are too thin, your firing pin won't reach correctly.

Sent from my SM-G781U using Tapatalk

[Noah Zark]

That makes no sense. A bobbed hammer should set primers off better, not worse. Skeletonized hammers are the best of the best for lock time and reliability. If that gun has the separate firing pin, make sure that is clean.

You are absolutely correct about improved lock time, but it's been my understanding that some guns in addition to mainspring force, require a certain mass of hammer/striker to set off the primer. For example, titanium firing pins in an AR sometimes don't set off 5.56x45 primers.

All that said, I have two M25-2s, two M1917s, and a M625-3, all unmodified, and all digest ammo loaded in R-P Auto Rim brass.

Noah

[MostlyLeverGuns]

slughammer suggestion - use a feeler gauge to check headspace with the R-P brass. Very long ago (before internet) I too had S&W 25 that was not accurate, probably chamber throats. I did have several misfires with factory loaded Remington 45 Auto Rim with that revolver, moon clipped 45 ACP, including US military issue always worked . I also have 32 special R-P brass with very thin rims, absolute SAAMI min, compared to other brass. I just received back order of Starline 45 AR but have not tried it in my two S&W Brazilian .45's, only used moon/half/third clips so far, without problem. There are many ways to get smooth, light triggers on S&W's without putzing with the mainspring.

[DocSavage]

Ok,just got back from the range with my 625. Firt off took the cylinder off cleaned under the ejector star just in case debris under it might be part of the problem. Cases primed with RCBS hand priming tool CCI primers seated slightly below primer pocket. 5 grs Red Dot 200 gr swc. Mixture of double and single action firing 1 failure to fire out of 20 rds. So my guess of poorly cut primer pockets was correct. These were R-P cases will try the rounds loaded in Starline brass later this week. Will update afterwards.

[44MAG#1]

I have had two of the Smith 45 ACP revolvers. I primarily used 45 Auto Rim brass.
No problems.

[243winxb]

Eliminate/Reduce cylinder end play. Shims are made for this. Midwayusa has a Youtube video.

Brass rim thickness should be measured & compared to SAAMI standards. 45 Auto Rim.

A test for a Smith and Wesson revolver, model 28, 357mag., may work on other guns also<> Gun empty.
Dryfire gun and hold trigger fully to rear.
Cock hammer with thumb.
Hook a weight around the hammer (for example 3 1/2 LB minimum weight for 357).
The hammer must not move rearward when the gun is lifted.
The hammer should lift 3 1/2 lbs without going into the cocked position.

Primers can be flush with the case head to .008" below.

Measure hammer nose/firing pin protrusion.

Is hammer rubbing frame? This slows the hammer. There are shims for this also.

Last, check headspace.

Better yet, see a pistol smith.

[KAYDADOG]

DocSavage, I had a similar problem with a new S&W 929 9/mm pistol using moon clips and CCI primers.
Talked to S&W and they stated to use factory ammunition which is never going to happen to a reloader.
Any reloaded ammunition should perform very close to factory rounds.

Changed to a longer firing pin, no change.

Long story short talked to someone at my firing range. He suggested to try Federal primers which may use a softer material.
Bought 100 to try and loaded them to the same parameters of the ones used with CCI primers.
Went to the range and guess what had zero misfires.
Luckily I bought 10/K Federal small pistol primers when they were still $150 per/1000 not like $600 now.

Only experienced misfires in this particular gun. Sometimes the solution can be a component used.
The 9/mm rounds with CCI primers work fine in any of my semi-auto guns.

Hope this helps. Just something to look at.

[tejano]

My 929 is also a federal primers revolver. I seat them down hard using a Lee Turret Press. Also, I have had my best luck with Lapua, Winchester, and Federal cases. My 625 has been federal primers only ever since the mods at SDM Fabricating were done years ago.

[DocSavage]

I have CCI and Remington primers on hand may try the R-P primers next. Will have to wait for primer prices to go down when that will happen Is anybody guess. I'm happy to have figured out the problem short of sending back to S&W or having a local smith work on it. I've got loads of 45 auto ammo and moon clips the auto tim brass makes life a bit easier to shoot

[slughammer]

..... These were R-P cases will try the rounds loaded in Starline brass later this week. Will update afterwards.

Can you measure the rim thickness of the RP and Starline brass?

Sent from my SM-G781U using Tapatalk

[Outpost75]

IIRC the 625 revolvers have a frame-mounted firing pin, rather than one pivoted on the hammer nose, as on older models. You need to measure the driven protrusion of the striker point with hammer down and trigger held back, which is easily done with the cylinder and yoke assembly removed. On a .38 or .357 driven protrusion should be 0.028-0.032". Not sure of current spec for a gun using large primers, but my M1917 S&W and Colt New Service with hammer-mounted firing pins are 0.040" and will set off rifle primers if primer pockets are cut deeper for them. They produce 0.018" copper indent, using the government gage. About the same as a .44-40 Winchester 73 or 92!

Head clearance and cylinder end shake are also factors as both reduce striker indent. WW2 spec for M1917 revolvers being rebuilt for reissue was 0.012" minimum on annealed copper cylinder held in the government gage holder. This is the same as CPB spec on .357 revolvers and for M9 pistol.

With frame-mounted firing pins you can have the issue of primer cup material flowing into the firing pin bushing when there is excessive radial clearance of the bushing hole around the diameter of the striker point. Most common in .357s. If thin cup primers used in +P+ or magnum loads produce punctures at the striker indent fouling and debris entering the firing pin bushing can bind the sliding fit of firing pin and reduce striker energy through frictional losses and cushioning effects. IMHO this was a poor design for police service!

When I was at Ruger in 1980s we went all around the mulberry bush to mitigate primer flow into the bushing and to insure adequate copper indent on contract guns. On CPB contract production they wanted 0.030" min driven protrusion with 0.012 min indent on copper. Normal commercial product was normally l held to 0.028 driven protrusion with 0.010 copper indent. good spec for .38 and .357 whichncurrent S&W often fail to meet.

[M-Tecs]

The early 625's had the hammer nose firing pin. It appears -4 was when the switch was made since the 625-4 can be found with either hammer style. The Smith & Wesson S&W Model 625-4 still has the pin in the hammer.

Pics here https://lsbauctions.com/5221/smith-wesson-sw-model-625-4-the-model-of-1989-round-butt-stainless-5-45-acp-double-action-revolver-case-mfd-1995/

[DocSavage]

Both revolvers are 625-8.

[376Steyr]

Both revolvers are 625-8.

Perhaps the Internal Lock System (AKA the Hillary Hole) has somehow gotten gummed up and is slowing the hammer fall?

[M-Tecs]

You can purchase a longer firing pin here.

https://tkcustom.com/products/s-w-competition-extended-firing-pin

https://www.brownells.com/handgun-parts/action-parts/firing-pin-parts/firing-pins/s-w-extra-length-firing-pin-prod60302.aspx

https://www.brownells.com/handgun-parts/action-parts/firing-pin-parts/firing-pins/s-w-revolver-extra-length-firing-pin-prod5483.aspx

https://www.apextactical.com/apex-revolver-firing-pin-kit

http://www.powercustom.com/store/index.php?main_page=product_info&products_id=303

https://www.wingtactical.com/firearm-parts/handgun/handgun-parts-accessories/apex-revolver-firing-pin-kit-for-j-k-l-and-n-frame-revolvers/

Some good discussion here

https://forums.brianenos.com/topic/251251-extended-firing-pin/

https://www.1911forum.com/threads/s-w-625-problem.402246/

[DocSavage]

Perhaps the Internal Lock System (AKA the Hillary Hole) has somehow gotten gummed up and is slowing the hammer fall?

Don't have a key for the lock but was thinking of giving the internals a spray of carb cleaner. The problem is with 2 different 625s one much worse than the other. I have vernier and will measure rim thickness and compare with drawings in Lyman manual and compare to Starline brass.

[DocSavage]

Just measured rims R-P .083 Starline .085 wiki say rim thickness .0827

[megasupermagnum]

Don't have a key for the lock but was thinking of giving the internals a spray of carb cleaner. The problem is with 2 different 625s one much worse than the other. I have vernier and will measure rim thickness and compare with drawings in Lyman manual and compare to Starline brass.

If you've never had the side plate off the thing, that is definitely the #1 thing to start with. Carb spray isn't what I would try, but maybe. I don't think you could do very good spraying it down by the hammer. You definitely want the side plate off, and give it a proper cleaning. Clean your firing pin while you are there.

[DocSavage]

Not going to remove side plate on my own too much of a chance of part s launching themselves into orbit or that black hole where all small parts seem to end up. Will look at IL with a jeweler's loop as it might be an allen screw or torx.
Worse comes to worse I'll contact S&W for a key.

[slughammer]

Just measured rims R-P .083 Starline .085 wiki say rim thickness .0827OK, so the brass is in spec.

Do you have a set of feeler gages? A few of us could check our headspace and we could compare measurements.

My 625 Model of 1989 with the hammer mounted firing pin measures right about .102 - .103 for headspace.

Firing pin protrusion is not as easy to measure, but you can visually look at it by opening the cylinder, then pull the thumb latch to the rear and hold it there, you can now pull the trigger double action and see the firing pin protruding from the frame. After that you can tie the trigger back and examine it further. (3 hands may be necessary.

https://i.imgur.com/Pw5SW5K.jpeg

https://i.imgur.com/Q5O1Wxk.jpeg

[DocSavage]

Going out Saturdsy with a batch of 45 acp in moon clips to see if I get the same results as the auto rim brass. Might just get a longer firing pin and have my local gunsmith install it. %20 for the pin and $45 for labor,cuts down pn the aggrevation dept.

[Geezer in NH]

Trigger job done on it check the strain screw some smiths take a little of the tip of the screw so even tightened down it does not hit the mainspring enough. I would try a new factory screw.

[DocSavage]

Bought the 625 used but it's been reliable up until recently. Have checked the strain screw first thing though I was thinking of putting a small piece of lead shot under the strain screw.

[rintinglen]

Back in the day when revolvers ruled the earth, at least the holsters of law enforcement portion thereof, there were a fair few fellows who would grind the tip of their main spring strain screws to lighten the trigger pull. Sometimes to the point of causing light hammer strikes. A quick and dirty fix for this was to take a spent primer and pop out the anvil. Back off the strain screw until you can just slip the primer over the shortened screw and then retighten. This usually fixed the problem.

Sometimes it took taking a small primer, popping out the anvil and inserting it inside a large pistol primer cap. I never knew this to fail.

In this case, I'd install a longer firing pin. Five to ten thousandths should do the trick.

[tejano]

Funny, I had completely forgotten about the spent primer trick even though I used it myself back in the 80’s. The odds are good that it will extend the life of a “relaxed” mainspring, especially with Federal primers. Mine is a 625-2 model of 1988 so the firing pin is on the hammer.

[DocSavage]

Pulled the grips off the 625 strain screw is intact,called Apex Tactical and ordered 2 new firing pins.
If I'm replacing one pin may as well replace the pins in both 625s.

[Char-Gar]

The hammer on a 45 ACP DA revolver has quite ways to go to smack the primer. They need a stout spring to insure reliable ignition.
When folks jack with the mainspring stuff like this can happen.

[DocSavage]

Well finally made it to the range after having n Apex firing pin installed.
60 rounds fired da/sa no misfires combo of 45 acp no moon clips/45 auto rim.