what to check when contender misfires and uneven lockup

[ruger438]

today I tried 45 colt loads in my 45/410 barrel. 1 in 3 cases would not fire, no firing pin strike on primer. Those cases also do not allow barrel proper frame lockup, which of course causes the non-fire.

The 410 shells work great, and the 17 hmr barrel works great as well.

The 45 loads are handloads, new winchester brass, primers appear to be seated correctly.

What did I do wrong?

[Dezynco]

I just ran into this problem myself.  The locking lugs on your barrel are not seating deep enough to kick that little "bowtie-looking thing" into the correct position.  Unless that flips around to the correct position, the hammer block mechanism will not drop out of the way.

Give the locking lug on the barrel a good cleaning and oiling.  The lock lug is the spring loaded block under the barrel assemby that is sorta shiney, about 1/2 inches wide by 1/8" tall.  Also look into the frame where that lug should slide and make sure it's clean and oiled.

If this does not cure your problem, you'll need to VERY CAREFULLY give the locking lug a polish with a fine stone.  All you'll need to do is take a "coat of paint" off the spring loaded lug on the barrel, mostly around the sides and bottom.  Maybe round over the shoulders a LITTLE.  Don't get carried away, any thing other that  polishing should be done by a gunsmith.

If THAT doesn't work, you'll need to consult your gunsmith.

[Dezynco]

Wait, Wait!  Before you start doing some home gunsmithing, are you giving the gun a good, firm shut when you close it?  I'm not talking about slamming the hooey out of it, but a good firm "Kachunk" when you close it?

That can help a great deal with a barrel that does not lock up welll.

[RonF]

Yes, wait, wait, indeed!  The fact that the .410 shells work great suggests it is not your barrel, but your handloads.  I have no idea what the problem may be, but I don't think it is your locking lugs.

RonF

[lastchanc54]

One thing you can check is your roll crimp on your 45's. You don't need much if you are only shooting them out of a single shot handgun. Excessive crimp can and has caused grief for other Encore owners. Good luck!

[David D.]

Yes, wait, wait, indeed!  The fact that the .410 shells work great suggests it is not your barrel, but your handloads.  I have no idea what the problem may be, but I don't think it is your locking lugs.

Handloads would be my first guess. By all means check that out before doing ant honing.

[Lanny]

today I tried 45 colt loads in my 45/410 barrel. 1 in 3 cases would not fire, no firing pin strike on primer. Those cases also do not allow barrel proper frame lockup, which of course causes the non-fire.

The 410 shells work great, and the 17 hmr barrel works great as well.

The 45 loads are handloads, new winchester brass, primers appear to be seated correctly.

What did I do wrong?

Take your barrel off of the frame, and hold it vertical...Drop one of your .45 cartridges in and see if its flush..
the barrel acts like a case length guage.....

[ruger438]

well I was fairly sure it was my handloads, but I didn't know what I should look for. 

I will check the roll crimp. I can tell which round will not fire as soon as I close the action. It just doesnt quite "click" the same. But with the long 410 chamber, I was at a loss as to why some cartridges wouldn't allow the action to close.

On a related note, is the 410 chamber larger in diameter? The reason I ask is there appears to be gas leaking back past the outside of the brass along the chamber wall and back into the action.

Could powder fouling in the action cause the misfires,and do I have an unsafe condition?

The cases are blackened partway back the case on the ouside of the case.

I've had that happen in revolvers already with low pressure loads that don't expand the cases fully against the chamber wall, but this is 20.5 grns of H-110 behind a 300 grn sierra JSP. I was thinking the generous freebore was lowering pressures, preventing the case from expanding fully.

Anyway thanks for the replies, and I will check the roll crimp and also see if the cases drop flush with the barrel