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View Full Version : AR-15 A3 Bolt Stuck Back


Edward429451
September 18, 2006, 12:03 PM
My buddy's Bushy has the bolt jammed in the rear position. He's going to bring it by tonight so I (the gun expert lol) can have a look at it.

It's a stock A3 Bushmaster. He says it was pristine clean when he took it out yesterday, and dripping with oil. He ran a whole bunch of rounds through it and its filthy now. He's already beat on the forward assist with no luck.

What could cause this? How do I get that bolt to release and what to look for? I haven't seen it yet. Thanks in advance.

T. O'Heir
September 19, 2006, 12:46 AM
"...beat on the forward assist..." That's for closing the bolt, not releasing it.
"...dripping with oil..." Bad thing, but not the cause of the bolt locking back. Look at the trigger group. Something is loose.

Edward429451
September 19, 2006, 01:49 AM
I thought the forward assist was for either if it didn't go fully into battary or if the bolt stuck rearward. No matter. It seems to be stuck in the stock, I was able to pull both receiver pins and seperate the upper & lower enough to move the hammer and the bolt hold open device so its not hung up on anything in the lower. It's stuck in the stock. He's never pulled the spring out and cleaned it. I didn't want to go any further and told him to take it to a real gunsmith who it'll probably be an easy job for.

sleeping dog
September 19, 2006, 07:26 AM
beat on the forward assist
If you want a gun to beat on, get a Mosin Nagant. They're designed for abuse. :)

If the problem is with the spring, it should be pretty easy to remove the buttstock and the receiver extension (buffer tube). Just watch for the tiny spring and detent that will fall out of the receiver when you remove the buttstock. If the receiver extension is glued in, removing it may destroy it. They don't cost much to replace. I don't glue mine in, just torque to about 30-35 lbs.

If the problem is not the spring, removing the extension tube should let you twist and turn the bolt to try to get it to move forward. I wonder if the gas tube in the receiver got bent and is holding the bolt back.

Remember to put all the parts in a box so you can take the whole thing to a gunsmith when all else fails.

Is this a "real" Bushy? Bought as a full rifle? Give Bushmaster a call, see what they recommend.

Regards.

FS2K
September 19, 2006, 08:11 AM
The bolt is never supposed to go into the buffer tube....are you saying the buffer was stuck?

If the bolt is indeed in the stock, something muct have happened to the buffer retention pin & spring. In any casem even if it is the buffer that is stuck it's probably due to the retention spring getting jammed somewhere up in there. 9 times out of 10 that's the problem.

sleeping dog
September 19, 2006, 08:21 AM
The bolt is never supposed to go into the buffer tube
I thought when the bolt is "open", the bolt is sitting mostly in the buffer tube, until the buffer pushes it forward into battery, under power from the buffer spring. I'm at work now, but I'll have to look at the ar when I get home.

I agree the buffer retention pin and spring could be a cause. Is the buffer retention spring the one that falls out when you remove the pistol grip? Maybe removing that is a simpler first step than removing the buffer tube.

Regards.

Edward429451
September 19, 2006, 10:08 AM
To clarify, Beat on the forward assist was a figure of speech, as I'm pretty sure it was when he said the same thing to me. The bolt itself is not stuck in the buffer tube, the bolt carrier is stuck in it.

I may not even get to hear about the outcome, it was a friend of a friends rifle, but if I do, I'll let you guys know what it was.

The rifle is a factory complete Bushy, 6 or 7 years old, shot about 500 rnds a year and stuck in the closet (<figure of speech!):D

FS2K
September 19, 2006, 11:10 AM
"The bolt is never supposed to go into the buffer tube"

I should have said "Go all the way (entirely) into the tube" ..

Sorry.

Edward429451
September 19, 2006, 11:16 AM
The bolt is right at the rear end of the ejection port just like when its locked back on an empty mag. The buffer retaining pin sounds like a good bet.

IZinterrogator
September 19, 2006, 11:26 AM
Is the buffer retention spring the one that falls out when you remove the pistol grip? Maybe removing that is a simpler first step than removing the buffer tube.
No, that is the retaining pin for the safety. The buffer retention spring is held in place by the buffer tube being partially screwed over it. I doubt that is the problem, unless the buffer tube is loose already.

sleeping dog
September 19, 2006, 12:59 PM
Thanks, IZinterrogator, it's been a while since I played with the little parts inside the receiver. So, the little spring and detent that fall out when the buttstock is removed, is that the one that holds the rear takedown pin?

Loose buffer tube? Good idea. That's another good thing to check for. If that backed out and let the retaining pin fly up into the bolt, that might lock it back.

Regards.

Powderman
September 19, 2006, 04:20 PM
Sounds like someone forgot the buffer itself.

1. Clear the firearm.
2. Look at the buttstock.

Fixed? Get a nice sized flat-tip screwdriver, and unscrew the rear upper stock screw. Slide the buttstock off the buffer tube. Watch for the detent pin spring and detent pin that will come out of the small hole under the forward part of the buttstock.

Collapsible? Get the appropriate spanner wrench, and unscrew the lock nut. Remove the buffer tube, and let the spring expand slowly.

On the fixed one, get a crescent wrench, have someone hold the receiver flat on a table, and give the wrench a sharp rap, counterclockwise. This should break the tube free.

Remove the tube and spring, and remove the bolt.

Inspect the bolt carrier for damage; peening, shaving or deformation.

Clean and service the bolt and carrier.

Replace the detent pin that holds the buffer in, and the spring.

Inspect the buffer for damage, and inspect the spring for kinks or damage. Replace as necessary.

HINT: A drop of oil in the detent spring will prevent rust and assist in smooth operation.

Reassemble and test fire.

Edward429451
September 19, 2006, 05:38 PM
That sounds pretty easy powderman. Think I'll call him and have him see if the guy took it to the gunsmith yet, give it a try.

Thanks!

IZinterrogator
September 21, 2006, 11:49 PM
So, the little spring and detent that fall out when the buttstock is removed, is that the one that holds the rear takedown pin?Yep, that's it.

Edward429451
September 23, 2006, 09:16 AM
It was the buffer retaining spring & spring as FS2K said. Powdermans instructions to remove it worked like a charm. Everything looks good except the spring which was munched.

Thanks guys, saved him a bit of money.

Said he was rapid firing with Mil surp when it happened. Is this rare occurance or should I have an extra new spring in the box for the possibility of it happening to me with my Bushy one day?