Bolt carrier hanging.

[DrDeFab]

Some background info: this is my fourth build, but my first (and LAST) build on a Ewbanks. I know bolt carriers normally hang due to rail problems or the hammer profile.

If I remove the hammer, the carrier seems to ride fairly well in the rails; with the hammer in it hangs up when pulled back to within about two inches of full stop. Give it a moderate tap forward and it snaps shut fairly briskly. So I'm assuming it's the hammer profile.

After four cycles of file/sand/polish, it is only marginally better, and still hangs back every time. There is no sign of contact with the cross-post. There IS a rub mark on the bolt shaft, so the hammer is pushing up on it fairly hard. I have also polished the carrier and lubed everything.

At this point, I've removed a lot of material and only have about 3/32" more I can take off before sear engagment becomes a problem.

Any suggestions? Keep taking off material? Something obvious I've missed?

Thanks.

[Ding]

welcome doc.nope,just a lot of break in time will fix it.hand cycle it from here on to help it break in.

[Etek]

+1
Run a hundred rounds through it before you modify anything else.

[motorhead]

grease it real good and shoot. see if it improves.

[AK Hunter]

Your bolt is dragging on the hammer, sounds like to me. As long as you keep it oiled & you’re not getting any metal shearing, or guild marks on the bolt or hammer. Keep cycling it to loosen it up. I had one like that just ran about 2-300 rds through it works fine now. It is still cycles stiff but that will go away(I hope) after a few more rds.

[jwc0506]

sh*t i wonder if the recievers' rear cutout(by the rt) is too long? you said it hangs up 2" to the full stop when you cock your rifle right? ya might want to try a recoil buffer to see if that helps? i may be wrong though? i would look at it, cause from what your description says-it sounds ya gotta hang up of the bc hangin up at the rear-and that should not be happenin at all. i mean, if it was hangin up on the bolt you would see it with the top cover off. have ya tried lookin at it with the cover off yet? if not remove ur cover and see where it is hanging up.

on my last 3 builds i have not had a issue with any bolt hang ups-after i fine-tuned my top rails, cycled in many times, lubed it up etc... a good cycling bc-SHOULD allow the bc to literally fly over the hammer-this bouncin right on over it. heard of a few folk's havin to have to smooth the hammer-i have not had to do that yet. lol.

[NorincoKid]

I just experienced this problem too, but its odd for mine because it worked fine as screw build, but after de-screwing and riveting it, it hangs up after each shot. Sometimes it does return, in a weird ratcheting slow movement. Its also extremely diffucult to remove or install my carrier....

I think my problem is the same....

[vandy]

I use lapping compound on those surfaces and cycle the action until smooth, 3-400 strokes, clean and do over again. Keep the lapping compound away from the bolt mating surfaces, there are a few mods you can do to make it better from there. It will never be as smooth as a M1a supermatch but it can be made far better than "as issued"
Vandy

[jwc0506]

Vandy-that helps! anything to get the bc cycling smooth is key to get the motion that will literally steam rioll the bc & bolt right over that hump of the hammer. if the dang bolt is hanging up on a portion of the top rails-it'll need to be smoothed out there on the top rails... now if it's hangin up at the very far back bolt drop in cutout-then a solution is to get black jack, or recoil buffer. now i don't know what the case is? but as a builder ya have to look at all possible culprit prbs-then take it from there. TWEAKING your gun to make it work is as important as it is to build a picture perfect rifle. like a doctor-if he has no clue what is wrong how can he/she help you. anyone how you have to look at the entire build, scope it out to find the ieeues-then fix um. that is tweaking.

[jwc0506]

now if this issue was my rifle i would probably remove my recoil spring and check the cycling. lube it up also. then you'll find any high spots on the top rails. fine-tune um up with a hand file, or a dremel with cut off wheel. just barely turn the wheel inwards the skin off the high spots and kinda true it up with the rest blending it in. a hand file may provide more control for those who feel it's just too difficult to mess with a power tool. anyhow-check this out 1st.

now if it's hangin up at the far,m far back at the bolt drop in cut outs-then the only solution is the recoil buffer. unless ur a master welder and also pretty good with a dremel you could possibly build up with was missing. it's simpler to just get the recoil buffer.

the final option is to smooth out the humnp on the back of hammer. i have not had to do that so i will leave it alone. all of this info i am adding is from that of a seriious novice home builder. i may not be pro, but i take my builds seriously.

[jwc0506]

bigwhell - what ya say may just be true? i don't know as i have not tried that mod ur talking about. but if it works-it's worth doing right!? not knocking the idea, but i like to NOT alter existing parts if i don't have to. the only time i would add weld is if it was buggered up and missing a piece of metal. like they say, "if it aint broke don't fix it." if his recoil spring push button is screwed over-yea fix it! or replace it. if not i would leave it alone.

[jwc0506]

Originally Posted by NorincoKid

I just experienced this problem too, but its odd for mine because it worked fine as screw build, but after de-screwing and riveting it, it hangs up after each shot. Sometimes it does return, in a weird ratcheting slow movement. Its also extremely diffucult to remove or install my carrier....

I think my problem is the same....

up front-im just a novice home builder-not a gunsmith! but my rifles work and funcion flawlessly-knock on wood! i plan to keep it that way-period.

if you're having difficulties dropping in your bc-here's sum suggestions;

ok now at the far back by the push button spring location-that gap where the bolt drops in. well my exp. and personal notes tells me that length should be no more then 20 mm's. so from the-TANG forward the rails where you have there are almost nill as ya have to file away almost all of it side-to-side in order to get your bc to drop correct. ok front-to-back you want 20mm's take it or leave it. another rule i was told by one of the AK FILES Gurus is to; have no more then an 1/8" play when the bc is in the reciever-but preferably less play. the 20 mm's i am talking about suits me well-both on 74's and 47's. hope this helps. take note of this. then you NEVER have to worry about the bc sailing out towards the back, hang-ups etc, etc..

yeah so put your bc in and it's too stiff you need slight trimming. just don't over kill! i left what i believe are the limits i would not go beyond.

also put your bc in and check it out. then slowly trim until you get the play i was talking about. what you would do is; remove the recoil spring to push slightly forward and back to get it right. again no more then an 1/8" play-but preferably less. this will update your builds into a higher level i think. good luck.

[jwc0506]

also the front, or middle bolt carrier drop in cut outs-Norinco kid- i was told that the left side is slightly wider then the right side cut outs. what i did with my bent flats was pre-mock-up my bolt above that middle area and draw around my bolt with a sharpie black marker. then just trim outwards on both sides until my bc dropped in. so you have the front and rear of the bolt carrier drop in cut out to get ideal funcioning. i just thought i would inform you since you sound like you want to get it right. and you are only trimming-just enough so that the bc drops in and no more. i hope that my tips help ya out. but if ya ever look at a factory akm you will note the LEFT side middle areas bc cut outs is slightly larger then the right.

[jwc0506]

Bigwheel -i will look into it. for now i got to the range and fire sum rounds. too much pc action gives me a migrane. l8ta & take care! Jim

[DrDeFab]

OK, thanks for all the suggestions. Tried most of them, but in the end I just needed to take off another 1/16" from the hammer profile and polish. It did help to compare to the contour of the original hammer - the G3 was starting to get a "hump" in the middle I needed to smooth out.

I also carefully stoned the sear engagement face on the hammer to ensure positive lock, since the tolerances were getting close. It now runs slick as a greased weasel.

[jwc0506]

just gueiing it sounds like your hammer pins where sitting on the high side? glad ya got it fixed. i suppose it's ok to have removed material off the hump. but i would not take material off by the thick flat part of the hammer that hits the bolt. but ya-shaving a sliver off the hump is fine.

[scotthmt]

both my rifles hang if you let the bolt go slowly, but if you let it go from far back it goes all the way forward and shuts. Doesnt affect anything, i look at it as a very touchy bolt stay open mechanism, lol

[AKBuilder7255]

You're fine.....If the BC would stick and function the way that you're discribing at the range in the actual firing mode, time to take a look, but by drawing back on the bolt carrier's charging handle very slowly all the way back and riding the charging handle a little forward they almost all catch at that spot when just built or are brand new with very little milage on them. Take it out and rock&roll with it...just needs broken in......T.C. Ken in Pa.

ps. If it ain't broke why look to fix it??????? lol Ken