Ejector problem and a question

[hcpookie]

Time spent at the range yesterday was very productive. I have eliminated light primer strikes by cutting more from the bottom front of the hammer notch in the bolt extension. I removed another 1/16” and suddenly I have 100% ignition.

It appears that I am still suffering an ejector problem. I’m using the trimmed spring setup. After some searching in this forum, I believe I have a mis-aligned rear section that is pointing *slightly* upward. Thus, the top of the buffer is impeding the rearward motion of the bolt extension. I think. I can say with certainty that hand-cycling the cocking lever has *zero* ejection problems. Only when recoil cycles the gun do I have ejection problems. Thus my conclusion.

And now to my question – is there a good way to measure alignment? It looks correct, but it is hard to tell when it is all assembled. My novel idea is to put a cap over the buffer and place a long rod or even a laser pointer in it so I can see if it is pointing up, or if it is centered.

Is the solution for a mis-aligned buffer, other than re-welding the back section, simply to grind/polish the end?

Is there possibly another solution to fit the symptoms?

FYI, I bought an inverter to use my dremel from the car battery while at the range - it was $40 at Home Depot and a GREAT investment! Just be sure to run the engine when operating the tools.

TIA
- Jerry

[js412000]

It sometimes helps to mark up the suspect parts with a felt tip pen. Then cycle the action and see if the ink is rubbed off.

[propos]

I had a similar problem with the buffer being off center. The spring would rub on one side of it. I disassembled the buffer assembly and found that the bolt was very slightly bent. The hole in the base of the bolt also didn't line up with the hole in the buffer. Once I lined up the 2 holes, the buffer was no longer bent to one side. Go figure. My 42 ejects flawlessly. How the damned thing ever got bent in the first place is beyond me.
Take your buffer assembly apart, Jerry, and see if the bolt is bent. That may be your problem.
I knew my rear section was straight after I welded it. I checked the alignment with my parallels and it was dead on, so I knew that couldn't be the problem. It wasn't until I started eyeballing the buffer that I noticed that it seemed to be off to one side. That's when I took it apart and found that the bolt was bent.

[JBaum]

An off center buffer spring is one of the things listed in the armorer's manual to check, with a bent bolt as a second possibility. It also says to make sure the buffer head is smooth and well rounded, and doesn't have any burrs for the recoil spring to catch on.

I would guess that the bolt impact on the buffer head can put quite a strain on the buffer bolt, and once it gets weakened from the shocks, it'll bend. Of course replacing it with a hardened bolt would be the ideal fix, with straightening and rehardening as a second choice. Lacking the ability to reharden it, rolling it on a perfectly flat surface, watching for a change in the elevation of the center of the bolt at least gets it straight. It may not make much difference with a semi, but I would think a full auto would just beat it till it was bent again once it bends the first time.

[hcpookie]

Thanks for the tips - I'll check out the bolt. I'm not 100% certain my section is aligned, but I did use my parallels to clamp it down when I welded.

It should be straight but I don't know how to check after the fact.

(slaps forehead) I just had a good idea - I have a 2nd parts kit still in grease... I can use that kit's buffer assembly and if it exhibits the same behavior, then either it has a bent bolt or the receiver is in fact off-center.

jbaum do you know the thread size? I may be able to find something with the same thread size in my shop. Barring that, it occurs to me that I could take a steel rod and thread the end on my lathe to be an 'alignment tool' of some sort. Obviously any mis-alignment would be amplified and be more apparent with a 36" bolt vs. a 6" bolt.

[JBaum]

Nope, I don't know the thread size

[propos]

I didn't replace my bolt. I just realigned the 2 holes. But I forgot to install a new pin. But I did use blue loctite on it and it seems to be holding up. I wonder who might have buffer bolts. I never thought to get another one, but it seems like a good idea to have a spare.
When I removed the bolt, I rolled it across the benchtop and I could see it wobble. I found out that it is a hardened bolt when I tried to straighten it. So I thought I'd better leave well enough alone and since I don't know what steel it is made of, I didn't try to anneal and reharden it.
I reinstalled the bolt and realigned the holes and I let it go at that. And it seems to be working fine.

[hcpookie]

A brief update. I discovered upon closer inspection that my buffer bolt was loose and was missing the retainer pin. It was backed out about halfway! I screwed it back in place and am going to the range again tomorrow Is there any special pin that needs to hold the bolt in place, or can just a cotter pin do the trick?

[weasel]

I made a new bolt out of a 7/16" harden cap screw. The thread size is 11mmx1.0 pitch. I bought a die, get large size, chuck into a lathe and thread by hand.
LOL

[propos]

hcpookie. I would say that a roll pin of the right size would work. One of thse days I'll get around to installing one in my buffer. But I should check it anyway. Maybe that's the problem with the 8mm conversion.

[hcpookie]

Another update.

OK I have secured the bolt - for now - with some safety wire. It works, but I plan to use a cotter pin once I find mine... don't know into which corner of my garage they walked off and hid.

Anyway, I have eliminated the bolt "wobble" and have discovered I still have an ejection issue.

Check this out - upon further investigation, I realized the buffer was "sticking" in the semi bolt carrier extension. I took it apart, realigned the cap and the spring, and it still stuck.

THE INNER DIAMETER OF MY SEMI BOLT CARRIER EXTENSION IS TOO SMALL!!

(insert forehead slapping moment)

It would seem that when I built it based on Pirate's "how I did it" page, I was too close in the tolerances. Thus, the buffer is sometimes dragging against the inner part of the bolt carrier extension. I am pretty sure this is the root cause of my ejection issues. I never had a chance to discover this earlier since I had not been able to get it to cycle completely, and assumed the other commonly-posted problems were my problem as well, such as too long a spring, etc. So my difficulty in charging the gun was not only due to a too-long spring!

I threw my dremel and power inverter in the truck, and at the range I played with my dremel and sanding wheels to open up the ID to adjust the bolt carrier's ID. Now I can pop off about 5-6 rounds at a time! My power inverter popped a fuse, so I didn't complete the tweak

I am going on the assumption that there should be enough play in the inner diameter of the bolt carrier to let the bolt carrier slide freely front-to-back along the buffer.

Hope this helps someone out there... I am not 100% certain I have figured it out, when I dump an entire belt I'll let you know.

[Bil]

When you get it figured out,please post pics and measurements.It will save some time on my build,as I am not at that stage yet.Thank you. ---bil