K-22 First Model Double Action Not Working

[PeteC]

Well i'm here if you need ? BTW why don't you carry it's a crazy world out there !!

'Cause I have to cross too many states with too many laws I know nothing about to get there, and the friends I go walkabout with have that covered. From snakeshot to "OMFG what was that?" rounds...

I'll post better pics of the trigger tomorrow. I took most of the action out now, but don't have time for pics this afternoon. Oh, and someone clipped the end of the rebound slide spring off, too. Sigh.

And, that line on the back of the trigger is actually a Patent statement to match the hammer! Who knew??

 

[muzzlestuffer2012]

All good !

Sent from my SM-T813 using Tapatalk

 

[Hondo44]

The first thing I’d do to troubleshoot the problem is:

Cock the hammer with your thumb. Does the hammer travel farther back then needed for the trigger sear to engage the notch on the hammer? If it does the trigger sear has been shortened by excessive honing, and therefore also too short to operate the DA sear.

If there’s no excess hammer travel after the trigger sear engages the hammer notch the next thing I’d check is the rebound slide for excess honing as dsf posted above. The easiest way is:
If you have another hand ejector, try its rebound slide. If that fixes the double action, get a new rebound slide. I’ve never had to fit a replacement.

If that isn’t the problem, try a hammer sear from another K frame, if you have one or buy a new hammer sear, a very inexpensive part. Also buy a Kunehauser manual for gunsmithing your K22.

 

[PeteC]

Viewing the video, I suspect the rebound unit.

One of the "tricks" to getting a smoother reset, especially if a lighter than factory trigger reset spring is installed, is to smooth out the top of the rebound unit. May be that when the unit resets & camming the hammer back into reset mode the boss on the top of the unit isn't sufficiently proud. Leaves the hammer a bit far forward and the DA angled too far to the rear.

That is possible. I took the rebound slide out of another similar frame, and measured boss on both using a caliper. The one in the K-22 measured .030, very close to the other one.

Or, could be plain old wear causing the entire hammer to not be cammed up as much as it ought to be. I'd check that part on the hammer to ensure it hasn't also worn. I don't see any obvious wear on the trigger sear surface, and the gun does not look like it has been fired much.

I did not see any obvious wear. Looks like the gun has not been fired much, just handled. I plan to remedy that!

BTW, careful dropping the hammer with the sideplate exposed. Might "kiss" the exposed edge of the frame on its way down.

Yeah, it might, and did. I noticed that, but thanks for the warning.

Cock the hammer with your thumb. Does the hammer travel farther back then needed for the trigger sear to engage the notch on the hammer? If it does the trigger sear has been shortened by excessive honing, and therefore also too short to operate the DA sear.

I don't think so. I do not see any signs of honing. I see some light machining marks on the sloping edge. The surface looks smooth and dark, not honed or polished.

I have not tried a rebound slide from another gun yet, or another sear. I DID try the earlier suggestion, made by @Protocall_Design. I borrowed a trigger from another gun, a 1943~44 Victory Model. I swapped hands, to make sure I did not create a timing problem. This does work to a point, and the swapped trigger now engages the hammer sear, barely. However the action is not as smooth.

I am attaching some pics of the rebound slide, hammer and trigger the gun came with.

 

[PeteC]

For comparision, pics of the K-22 and the Victory Model before the trigger swap, and a pic of the K-22 after installing the trigger from the Victory model.

 

[Protocall_Design]

Those are very good quality pictures. That helps a lot. I'll send you a trigger that I think may work, once we get measurements.

 

[PeteC]

Those are very good quality pictures. That helps a lot. I'll send you a trigger that I think may work, once we get measurements.

Thank You very much! Let me know if this is enough: Trigger Width .265, Length front to back .915, Height 1.73, Longest Dimension 2.003 inches.

 

[Nightowl]

I had to look, so I pulled the side plate off of mine. Hope the picture attaches. It appears that the sear sits farther forward on my gun. It functions very well.

 

[PeteC]

I had to look, so I pulled the side plate off of mine. Hope the picture attaches. It appears that the sear sits farther forward on my gun. It functions very well.

Yes! That is very helpful. Thanks for taking the time to do this. Now I know the trigger sear is the original part, and not a replacement or rework. Same for the rebound slide/boss (except the spring which was shortened about a turn on my gun. The shape of the trigger sear surface including the bevel seems to be identical also, and the amount of old grease is similar. ONLY difference is the position of the tip of the sear lever relative to the trigger, and the overlap is not as much as I expected based on post-WWII target guns. The difference is only 10~15/1000 of an inch!