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View Full Version : Bolt in my OLL AR gets stuck and can't rack


brokestudent12
12-11-2008, 2:50 PM
My bolt gets jammed every few rounds and sometimes it gets jammed really really bad as in almost impossible to rack the bolt backwards and needs to be pried back.

Only thing I can think of is that I bought a new BCG, is it maybe the headspacing is off or something?

when it gets stuck basically it will eject the old round but not complettely chamber the next round so it will misfire since the bolt isn't closed all the way. then i will try to rack the slide back and it will be very very difficult, sometimes it's just really stuck and i have to take the upper off.

Arkalius
12-11-2008, 2:56 PM
This happened to me on my OLL build, and I know what you mean about it being hard to open. It really doesn't want to come out.

After my first shooting session I took the gun home and cleaned it up. Make sure you clean the chamber area really well. Also, clean out the interior of the BCG where the bolt sits. Clean the bolt really well, especially the gas rings area. Then, apply a good bit of lube and work the bolt in and out of the BCG. With the BCG fully assembled and the bolt pushed in, you shoudl be able to hold it from the back and swing it like a hammer with a good bit of force and have the bolt fly out into the open position. If it doesn't or requires an extremely hard swing, it's probably too tight and might need some more working/lube. Doing this solved the problem for me.

Too short of headspace could possibly cause this but it is unlikely. I believe it's just a situation of the whole thing being new and the gas rings bind up inside the BCG with just a little bit of the fresh GSR that gets in there making it very hard to operate. Working the action manually and some good cleaning and lubing in there should solve the problem.

ohsmily
12-11-2008, 3:01 PM
WHAT AMMO ARE YOU USING?
What lubrication (and how much) are you using?
What upper is it?
What BCG is it?
How old was the upper when you put a new BCG in it?


We can't intelligently answer your question without more information

Technical Ted
12-11-2008, 3:26 PM
What's the stock configuration? If it has a coilapsible stock are you sure the receiver end plate isn't interfering with movement of the charging handle?

If the collapsible stock castle nut isn't staked, it can work loose and allow the receiver end plate to shift. This interferes with the charging handle. This can keep the bolt carrier from going completely into battery and make retraction of the charging handle difficult.

brokestudent12
12-11-2008, 3:35 PM
WHAT AMMO ARE YOU USING?I've used Remington, Miwall, Wolf, actually crappy wolf cycles the best
What lubrication (and how much) are you using?breakfree/clp
What upper is it?Bushmaster w/midlength gas
What BCG is it?dpms
How old was the upper when you put a new BCG in it?about 500 rounds old


We can't intelligently answer your question without more informationthank you

thanks

brokestudent12
12-11-2008, 3:38 PM
This happened to me on my OLL build, and I know what you mean about it being hard to open. It really doesn't want to come out.

After my first shooting session I took the gun home and cleaned it up. Make sure you clean the chamber area really well. Also, clean out the interior of the BCG where the bolt sits. Clean the bolt really well, especially the gas rings area. Then, apply a good bit of lube and work the bolt in and out of the BCG. With the BCG fully assembled and the bolt pushed in, you shoudl be able to hold it from the back and swing it like a hammer with a good bit of force and have the bolt fly out into the open position. If it doesn't or requires an extremely hard swing, it's probably too tight and might need some more working/lube. Doing this solved the problem for me.

Too short of headspace could possibly cause this but it is unlikely. I believe it's just a situation of the whole thing being new and the gas rings bind up inside the BCG with just a little bit of the fresh GSR that gets in there making it very hard to operate. Working the action manually and some good cleaning and lubing in there should solve the problem.

sounds logical. the bolt is pretty stiff in teh carrier.

also my ciener kit would not insert into the barrel i just tried it and it wouldn't push forward all the way so maybe it is dirty? i tried inserting it in 3 of my uppers (all were used at the range) and it won't go all the way in in any of them. weird.

Desert_AIP
12-11-2008, 3:55 PM
Need to lube the hell out a new rifle. Run it wet.

Take the bolt out of the carrier, put several drops of oil on the gas rings and a couple of drops on the body of the bolt. Insert it in the carrier.
Put a couple of drops of oil down the cam pin hole and on the pin and insert it.
Put a drop of oil on the firing pin and insert it.
Lube the contact points on the side and top of the charging handle, a drop on each "nub".
Oil the bolt lugs, then the four rails of the carrier (both sides top and bottom), several drops of oil on each rail.
Then install it it the upper.
Put a few drops of oil on a patch or rag and rub it on the putside of the buffer and the recoil spring.
Assemble the rifle and cycle several times by hand to distirbute the oil.
I usually place a few drops in the oil holes on the side of the carrier every few magazines while I'm breaking in a new rifle.
When you get home thouroughly clean it and re-oil as above.
Check the chamber for carbon build up. Wolf steel cases don't expand to seal the chamber so a a lot of blowby gas can deposit carbon. When you try to shoot brass cased ammo which does expand, the chamber is too tight.

Solidsnake87
12-11-2008, 9:51 PM
Hmmmmm. I'd check your chamber for obstructions and perform a thorough cleaning. Then I'd do a function check on empty cases.

You might have to send the upper in for work :(

J_Rock
12-11-2008, 10:14 PM
nm sounds like something is binding up the bolt

Ahhnother8
12-11-2008, 10:31 PM
It may be that the right side of the bolt release wedges in the small groove on the bottom of the bolt carrier. It is hard to explain exactly, and is difficult to see, but you can coat the side of the bolt release with something (whiteout), then cycle the bolt and see if your coating gets marred. This problem is not uncommon, and is just as you described. The harder you pull on the charging handle the tighter it gets. Search the web for a detailed description of this phenomenon.

The fix - grind a large radius on the top/side of the bolt release.

Lane

Seesm
12-12-2008, 1:16 AM
Broke student..that things sounds like a pile o cr*p I will take it off your hands pm me... :)

Hey but seriously if you have not worked it out my business partner has built tons of AR and can fix if the oiling and such does not work... Pm if need be.

redcliff
12-12-2008, 7:48 AM
Clean the residue out of your chamber from running Wolf ammo. A chamber brush on a cleaning rod chucked into a portable drill works well.

Why did you buy a new bcg? Was there a pre-existing problem?

Another way to clear the jam you're experiencing is to retract the stock (if applicable) and pull on the charging handle as you whack the buttstock onto the ground.. this is known as mortarring and is usually preferable to "prying" your bolt open.

Arkalius
12-12-2008, 11:21 AM
When it happened to me I would rest the gun on the bench pointing upwards, and use the end of the handle of a hammer to basically bash the damn charging handle downward to get it open. It really did suck getting stuck so bad. I guess new BCG just needs to run wet as one poster said until it breaks in.

aplinker
12-12-2008, 1:12 PM
Clean the residue out of your chamber from running Wolf ammo. A chamber brush on a cleaning rod chucked into a portable drill works well.

Why did you buy a new bcg? Was there a pre-existing problem?

Another way to clear the jam you're experiencing is to retract the stock (if applicable) and pull on the charging handle as you whack the buttstock onto the ground.. this is known as mortarring and is usually preferable to "prying" your bolt open.

This is all really good advice. It sounds like you're not running wet enough and you have a dirty chamber.

Prying isn't as good as a good whack.

bohoki
12-12-2008, 2:53 PM
so is it the bolt that gets stuck or the bolt is held by a stuck cartridge via the extractor


dies it ever get stuck just dry cycling it?