[sourceofuncertainty]

Hey guys,

I was at the range today with my Bulgy 74 krink, and on about my 6th or 7th round I encountered a failure to fire. Looked down at the gun and discovered that the hammer axis pin had jumped out of its notch in the right side of the receiver, causing the hammer to get stuck at a screwball angle. WTF?

The configuration is as follows: professionally built 74 krink on an NDS receiver. I added a Red Star adjustable trigger that's given me at least a few hundred rounds trouble-free so far, and the retaining device is one of those plate-type replacements for the shepherd's crook. The retaining device seems to be in the correct position, so I'm clueless as to why this happened.

Anyone got ideas? Should I ditch the retaining device and learn how to install a proper shepherd's crook? Wave the magic voodoo chicken before I go to the range? Something else I'm not thinking of? I was hoping to make this krink a go-to gun, but as you can imagine this level of reliability doesn't exactly inspire confidence.

 

[shadycon]

Was the pin in correct to start with? Is it the correct pin?I'm not an expert but reinstall pin, and check to make sure retaining plate engages the groove at the base of both pins. Good luck.

GUNS-R-FUN

 

[sourceofuncertainty]

I'm pretty sure it's the correct pin; it's what came in the gun and it was a reputable build. The odd thing is that it's been at least a couple of hundred rounds - maybe more - through it since installing the trigger group so I'd have expected a problem like this to come up earlier if I had installed the retaining plate incorrectly or made some other simple mistake along those lines.

 

[KMFDM]

Could be a few things.

Improper re-assembly or installation of the retaining device. It sometimes takes time for the pins to work their way out far enough to stop the gun from working. I had a 1960 AKM that had the pin walk out around around 500 rounds and was still firing at the end of the day (about 900rds ) albeit not in the F/A mode of fire anymore. I have seen this happen a few times also.

Improper receiver dimesions-unlikely though

Tolerance stacking between parts and receiver.

Defective parts somewhere.

 

[sourceofuncertainty]

Thanks for the feedback. I guess I'll switch to a shepherd's hook/crook and just see if the problem shows up again. I guess if I throw enough rounds through it it's bound to reappear if it's something other than the retaining device.

It would be pretty ironic if these $11 plates ended up being less reliable than the much cheaper alternatives like the original hook or an e-clip.

 

[BigAL]

I hate the shepards crook. i use either the chinese "L" type or the bobby pin type

 

[sourceofuncertainty]

I hate the shepards crook. i use either the chinese "L" type or the bobby pin type

I know what you mean. It's been ages since I've used either, but now I'm starting to second-guess those plates. I ordered a couple each of the L-types and the shepherd's type and will see which I can get to work. It never hurts to have a few options. I'd try e-clips but my first experience with one was having it pop off the trigger axis pin of a 74 I used to have... within the first 100 rounds of break-in. There's another confidence-builder for you! :roll:

 

[Eagles6]

Had the same problem with my SAR1 century build. The axis pin was a hair too short. Turns out it was a common problem with that batch. Replaced the pin and have had no problem.

 

[Zane Zackerly]

Look at the ejection port side of the rifle with the gun fully assembled. Do you see the ends of the axis pins sticking just slightly out of the receiver? Or are they indented and don't quite go all the way through the receiver?

If it is the second condition then something may be causing one or more of your axis pins to not go all the way through the receiver.

I had this on a factory new SLR107FR. The trigger pin was just long enough to contact the right side receiver hole (due to the 'X' stamp being shallow). What I did was take a multi-plier and deliberately bend a 'kink' in the shepherd's hook right where it goes into the axis pin groove. If you do this, kink it toward the left receiver wall. This makes the shepherd's hook have a constant tendency to keep the axis pin pushed toward the right side receiver wall.

My trigger pin sticks out of the receiver on the right sight just like it's supposed to now.

 

[sourceofuncertainty]

For what it's worth, I switched over to the L-shaped retaining wire on my problematic AKs and have no troubles since. At $3 each I'd say it's a bargain of a solution.

http://dpharms.com/axis-pin-retaining-wire-lshaped-p-34.html?osCsid=89f68f6a47485df08e7cd57b5a42abf4

They're pretty easy to install once you've had a little practice. I use a couple of Harbor Freight dental pic-type instruments to get them in. I can install one in just a minute or two now, no problem.