Ruger 22/45 MKIII misfires: crappy ammo or something worn out?

[wally]

The mainspring is like $2 so it's worth a shot trying that anyway.

Changing the Ruger main (hammer) spring is not a simple job! There is a large amount of pre-load. Disassembly is easy, but be careful things don't go flying. Reassembly is a bear. I believe Ruger recommends replacing it as an assembly.

I did it once and it challenged my ability to improvise suitable fixtures like nothing else before or since.

Those primer dimples look fine to me, assuming you are showing rounds that didn't fire. Multiple hits in different areas of the rim without firing pretty much means a defective round.

 

[1KPerDay]

Do you have another .22 firearm?

If so, is it having the same dud rate with this ammo?

Great question. Dunno why I haven't done this yet:

10/22 50 rounds, no malfunctions.
CMMG AR-15 conversion, 50 rounds, no malfunctions.
Advantage Arms 1911 conversion, 50 rounds, no misfires (many didn't cycle but they all fired. This pistol requires higher-powered ammo like mini-mags or golden bullets to run well).
Ruger Single Six, 50 rounds, no malfunctions.


All of the primer indentations from these firearms are deeper and more pronounced than those from my 22/45. I'm fairly confident it's something wrong with the gun. I will try to replace the mainspring tonight.

 

[1KPerDay]

For any interested I pulled a couple new federal value pack cartridges from the same box and took them apart. There is primer compound evenly spaced around the rim and there is no priming compound mixed with the powder. This leads me to believe that it's the firing pin strike that breaks up the priming compound. And apparently my 22/45 doesn't strike it authoritatively enough.

Top left is powder from unfired Federal cartridge, bottom left is powder (with priming compound mixed in) from misfired federal cartridge, and bottom right is powder (with some priming compound) from misfired CCI mini mag. The firing pin strike is again at the top of the U so I am assuming that in the case of the CCI the firing pin strike dislodges that portion of the compound but CCI's priming compound must be more adhesive or durable and it doesn't all shatter.

In any case it APPEARS that the federal ammo is as good as it ever was and my pistol is getting tired or worn. Reading up on mainspring replacement and trying to figure out a jig.

 

[Tacoma]

Firing pin marks look sold. I woulds suspect a crudded chamber is preventing the bullet from seating all the way. When this happens, some of the energy from the firing pin is used to seat the bullet (thus robbing energy). A peaned chamber edge can cause the same thing. Try cleaning the heck out of the chamber AND breach face with a good wire brush. Then retest with a box on high quality ammo like mini mags. If that works, you can walk your way back to cheaper/bulk ammo (FWIW, I find fed auto match pretty reliable.) IF it doesn't, I'd try respringing the gun and maybe a new FP.

 

[1KPerDay]

Installed new firing pin already. New rebound spring. I just installed a new mainspring and the first round I chambered misfired. LOLOL. Then out of 6 mags full, I had one or two misfires per mag out of 4 mags. So no real improvement. I will scrub the chamber again.

It SEEEEEEMS like the brass that fires has a more solid hit than the rounds that misfire. But I might be imagining things at this point. I love this pistol and it has served me and my daughter well for 15K rounds but at this point it's not reliable enough to use in competition anymore. What else could be causing inconsistent strikes? Hammer pin warped somehow? Egged out frame holes? I'm at a loss here...

 

[Mr_Flintstone]

I have read that the loaded chamber indicator can sometimes cause misfires. Check it for burrs or imperfections that may be causing the ammo to not seat correctly. You can check that by simply locking the bolt back.

 

[1KPerDay]

I have read that the loaded chamber indicator can sometimes cause misfires. Check it for burrs or imperfections that may be causing the ammo to not seat correctly. You can check that by simply locking the bolt back.

thanks for the idea but I removed that annoying device 15,000 rounds ago.

 

[243winxb]

Increase firing pin protrusion? Oops, i see you have a new firing pin. Should not be the problem.

 

[danez71]

thanks for the idea but I removed that annoying device 15,000 rounds ago.

Probably a silly question, is that about when the problem started?

 

[1KPerDay]

No it ran flawlessly for 10k rounds, and has been getting worse over the past 5K. Now it's about 1-2 misfires per mag on average.

 

[243winxb]

Make sure the recoil spring assemble is installed correctly, and not riding or dragging on the frame.

Top of the receiver, is what i should have said.

I see you broke one.

 

[1KPerDay]

Increase firing pin protrusion? Oops, i see you have a new firing pin. Should not be the problem.

anyone tried sharpening the firing pin? I assume this is a bad idea?

 

[1KPerDay]

View attachment 229898 Top of the receiver, is what i should have said.

I see you broke one.

The recoil spring/assembly is fine and installed correctly. I broke a couple rebound springs (the little one inside the front of the bolt under the firing pin).

 

[danez71]

What ammo brands... and with all.of them?

 

[243winxb]

anyone tried sharpening the firing pin? I assume this is a bad idea?

On a Mk1 i changed the shape on the firing pin. The face was not as wide.

At the same time, i cut coils off the main spring, recoil spring and the little one that puts pressure on the disconnector.

Plus had a smith drill 7 holes into the rifling in front of the chamber.

Did the trigger also. Many years ago. https://thefiringline.com/forums/showthread.php?t=583377

Here a link on firing pin. Not my info at link.


Another link https://thefiringline.com/forums/showthread.php?t=583382

 

[1KPerDay]

Why would you have the Smith drill holes into the rifling?

 

[FL-NC]

Could be Q-C issue with ammo, but you have fired rounds from multiple manufacturers. Why not send it back to Ruger and see what they say? Their customer service is top notch in my experience.

 

[243winxb]

Why would you have the Smith drill holes into the rifling?

To reduce recoil for international rapid fire pistol competitions, firing 5 shots in 4 seconds on 5 different targets, was the fastest stage. The holes vented gas/pressure early, making it almost recoiless. Got the idea from the American Rifleman magazine, when they did it to a High Standard.

There were 2 Ruger MK1 5 1/2" bull barrels made in the 70's. Wonder where they are now?

 

[1KPerDay]

Could be Q-C issue with ammo, but you have fired rounds from multiple manufacturers. Why not send it back to Ruger and see what they say? Their customer service is top notch in my experience.

My experience as well. Problem is I had the grip frame modified and 1911 panels/bushings installed, and custom extended mag release. I'd have to buy a new OEM lower to send back. Plus I have installed a clark bushing to the OEM hammer in place of the disconnect safety and that bushing is NEVER coming out. LOL

 

[1KPerDay]

On a Mk1 i changed the shape on the firing pin. The face was not as wide.

At the same time, i cut coils off the main spring, recoil spring and the little one that puts pressure on the disconnector.

Plus had a smith drill 7 holes into the rifling in front of the chamber.

Did the trigger also. Many years ago. https://thefiringline.com/forums/showthread.php?t=583377

Here a link on firing pin. Not my info at link.

I wish ruger would have sent me one of the new type firing pins rather than the old type. I'd like to try the new one. I was thinking of trying to sharpen the tip of one of my existing firing pins anyway. Looks like the idea is sound.

 

[ColtPythonElite]

I have 5 MK pistols. I have only had a chronic misfire problem once. I found the rebound spring support had broken.

 

[1KPerDay]

I have 5 MK pistols. I have only had a chronic misfire problem once. I found the rebound spring support had broken.

The little lazy-L shaped plunger the rebound spring fits onto, right? Mine looks good. thanks for the ideas.

 

[pintler]

FWIW, I've seen high round count 22 pistols build up a very thin layer of hard to clean stuff in the chamber. When a cartridge on the high end of the tolerance band comes along, it won't quite seat. The firing pin seats it all the way, but seating it uses some of the firing pin's energy, and you get a light strike. The solution is a very thorough cleaning (bore brush and electric drill?). I've even seen people use a 22LR chamber reamer that pulled out something that wasn't steel, when brushing didn't work.

 

[1KPerDay]

Thanks, that makes sense. I've scrubbed the chamber really well a couple times and it's clean.

 

[Mr_Flintstone]

Have you taken the barrel off and hand inserted a round into the chamber? Seems to me that would tell you if a round was seating all the way down, or if the fit was too tight.