Inconsistent primer strikes with 327?

[Echd]

My well-loved r8 appears to have recently developed an issue with light strikes and I was hoping someone may have a good guess at the cause.

When I first purchased the gun I put a lighter mainspring in it; I shot almost entirely federal primers so that quick fix alone gave me quite a good trigger. Regardless I never had any problems with ignition with anything else but I bet 90%+ of what I shot was federals.

Recently I have had trouble finding federals locally and have swapped over to much harder CCIs. My first range session was awful, tons of light strikes. I went back to the house and stuck the OEM mainspring back in. I went back to shooting and while I did have fewer light strikes, I was still getting them on occasion.

The strikes are inconsistent; while the fast majority look like solid strikes and good hits, the light strikes have only a very small dimpling of the primer. An extremely light dimpling. Some will fire on a second attempt, some will not.

My thought at this point was poor primer seating- I load my 357 on a 1050 so primer depth is set mechanically rather than by hand like with most progressives. I grabbed my trusty hand primer and made sure sure each primer was seated correctly slightly below flush.

I'm still getting light strikes though, probably one every other cylinder.

What I have tried-

My strain screw is fully tightened. It isn't going anywhere.

I've tried a couple of main springs. Previously I never had any issue with this gun with lighter springs in general. Currently I put the OEM mainspring it.

I purchased an Apex extended firing pin kit. I have not had a chance to use it yet.

Let me know if you have any ideas as to my issue, please.

 

[AtomHeartMother]

If you're not using moon clips...or using bent moonclips, both scenarios can be a problem with harder primers. I too, try to use federal primers only in my TRR8. I run the stock mainspring with the strain screw all the way in. The longer firing pin is your friend...it ended light strikes in my revolver for good. I do also ensure my primers are bottomed out in the shell when I reload as well. Can't remember what firing pin is in mine off hand, but I do remember the instructions recommended not dry firing it once installed...fyi.

 

[BLUEDOT37]

I purchased an Apex extended firing pin kit. I have not had a chance to use it yet.

Install it. The Apex's run .500", factory FPs run ~.490".

Apex changed from the rounded nose to a pointed nose, which I don't like so I switched to a C&S extended firing pin. They run .510" & have the broad rounded nose like Apex used to.

My TRR8 has a fair amount of gross headspace plus a little endshake (have you checked your endshake?). The longer FP offsets them. I have a C&S in mine.

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[Echd]

Moon clips are a good idea. I considered that but dismissed it, mostly because I forgot my clipping tool when I took the gun out last night. I'll give it a shot, but regardless the gun was previously very reliable even without federals or moon clips, so I'm assuming the problem has developed over time and the federals I normally used was masking the issue.

My Apex pin should be here Saturday, I will try it and moon clips. I don't particularly mind shooting with moon clips only, but I don't like the idea that it is mandatory for function.

I will need to borrow some gauges to check endshake.

There is probably somewhere between 10000 and 12000 rounds through the gun, all reloads and mostly modest 357s. It has generally been one of my favorites, but I shelved it for a few months and found this problem a few weeks ago when I brought it back out. I've probably had it for 4 or 5 years.

 

[3rdgeargrndrr]

Bad primer batch. Try them in another gun. If it goes bang, youll be playing with another gun for a while.
Or Time to get out the bullet puller

 

[Lou_the_welder]

It is not critical to use moonclips in that revolver, especially in primer strikes, as the cases headspace on the rim of the cylinder.
I'll say it differently. You do not have to use moonclips.
CCI primers are the hardest to ignite. Winchester primers fair better with federal being the easiest. I would not use CCI, especially on a high mile gun. Tolerances being what they may, looser tolerances may not be so kind.
I use Winchester primers but did have to throw a mainspring away. It became too loose. That R8 is a performance center gun and uses a ribbed mainspring. They "boast" a 30% reduction in DA.
These mainsprings are "lighter" than a lightened Wilson combat mainspring. But my fix with my R8, was to use a Wilson flat mainspring and kept the original firing pin. It fires Winchester primers just fine.
Just remember, no dry fires with extended firing pins, as that may cause them to break . You can use it and it will help, but I absolutely recommend against CCI primers. As they are the hardest to ignite anyways.

 

[nipperdog]

I was Having a 50% Failure rate with reloads in my 460 with CCI Primers.
I started Loading with Federal Primers and the Problem was Corrected. The Gun is 100% Reliable. My gun has had no problem firing Commercial Hornady Ammo.

 

[dr. mordo]

I concur with BLUEDOT37 - C&S firing pins are the way to go. I've had light strikes in a number of recent manufacture guns, some with stock springs AND an Apex firing pin, but the C&S pin cured them all.

I'm at the point where I replace the firing pin before I even fire a new gun.

That said, folks say the C&S pin is more prone to breaking from dry firing without a dummy round. I haven't dry fired mine much because of their warning, but I have to have a couple hundred dry fires on my 3" M629 with no issue so far.

 

[1sailor]

This is not an actual "fix" but it sure helped my M686. I was suffering from light strikes about 3 or 4 times out of every 50 rounds. Just to see if it would help I used the old trick of removing the anvil from an old primer and fitting the cup over the end of my strain screw. Never had another light strike after that. Not a single one and it's been quite a while now. It cost me nothing and took only a couple of minutes to do.

 

[BLUEDOT37]

Some times you win...

I'm at the point where I replace the firing pin before I even fire a new gun.

I started thinking, & doing, the same thing. In general, my observations have been (not scientific fact) that my auto cartridge (45ACP) revolvers & revolvers cut for moonclips (327TRR8, 627PC, etc.) tended to be the ones that had light strike issues right out of the box (I usually load up some primer only cartridges & test fire them into a wet rag in the garage before taking it to the range the first time).

So when I bought the re-introduced 610-3, when it came out, I decided to forego any of that & installed a C&S extended firing pin in it before taking it to the range, even though the factory firing pin measured a not too awful .490".

At the range, firing my usual 10mm auto handloads, I started having issues with not being able to SA cock the hammer after having just firing a round. I finally was able to see what was happening, the firing pin was sticking in the primer occasionally & not releasing quickly prohibiting cylinder rotation & cocking.

Deciding it had to be the C&S, even thought I never had any related issues with one, I put the factory firing pin back in & haven't had that problem reoccur since, even after re-chambering it for 10mm MAG.

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Once I get my revolver broken in, & the action/trigger pull the way I like it, I usually don't dry fire it much but having one installed doesn't really deter me either. I've seen pictures of the broken ones, & maybe I've been lucky, but I always have spare firing pins on-hand if the need arises.

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[Echd]

Looks like the Apex pin fixed it. I put a couple hundred through it today with no issues. Not sure why the old one got worse over time, but it was an inexpensive fix and hopefully if someone else develops those issues like I did they'll just drop the whole $15 on a new pin and be able to fix it as well if they find this thread.

 

[Hondo44]

The strikes are inconsistent; while the fast majority look like solid strikes and good hits, the light strikes have only a very small dimpling of the primer. An extremely light dimpling. S

Just FYI: The large dimple of a fired primer is not caused by the strength of the firing hit, it's from the primer flowing back around the firing pin when it goes off. When a cartridge fires, the primer is blown back partially out of the primer pocket, the pushed back in when the cartridge head hits the recoil shield.

In other words, even if the firing pin hit with enough full force to ignite the primer, if the primer didn't ignite, you'll get the same light primer dimple as a failure to fire. To illustrate this, you can deaden a good primer with WD-40 or the like, put it in a case and shoot it in a gun that never miss fires. You'll get a tiny little dimple on the primer.

Back to your problem. What puzzles me is why your full strength mainspring is now giving FTFs. With 10K to12K rounds thru the gun, have you ever flushed the gunk out of the firing pin hole and re-oiled? If not flush it with a good spray cleaner. I've seen this cause many FTFs. If that cures the problem you can probably go back to your lighter aftermarket spring; except maybe not with the CCI primers.

The old rule of thumb, "When problems arise, don't start trouble shooting without first doing a brisk cleaning and re-oil."