AR15.Com Archives
 50 beowulf problems
Highandright  [Member]
3/15/2012 9:26:55 AM
I just finished my new BW upper and made 2 trips to the range and it does not cycle the bolt hard enough to extract a round or lock back on a empty mag.

Before the first range trip I cleaned all the parts lubed with CLP and it wouldnt pull a empty case out of the chamber ( I had 2 extract all the way but the case landed right next to me on the table). I can pull the charging handle and it ejects easy and smooth.

So I go home strip it down clean it again dont see anything wrong. I push a hose onto the gas tube and can blow into the barrel no restriction. I switch out the bolt carrier to a lighter one I have just to see.
I head back to the range and it extracts and feeds 3 times but short cycles the rest. really no change.

Any suggestions?

Is it possible to somehow install a gas tube wrong but still can blow threw it?
Thinking maybe gas port is to small.

Parts list:
Liberty .50 Beowulf barrel
PRI Gas Block Single Picatinny Rail AR-10
Alexander arms bolt
mid length gas tube
Aero precision upper kit
rifle length buffer /spring of a known working 20" 556 lower

Ammo:
factory 335fmj Rainier

Thanks for any help


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RDTCU  [Team Member]
3/15/2012 9:40:59 AM
Gas block may not be lined up properly with the gas port in the barrel. Pull the gas block and measure from the step in the barrel to the gas port. Now do the same on the gas block. You might have to pust the gas block forward a bit.
The other possibility is that you need to open up the gas port in the barrel a bit.
USMC2147  [Team Member]
3/15/2012 10:04:16 AM
^^^This. You aren't getting enough gas back to cycle the bolt. Somewhere you have a misalignment or a blockage. Was any of your gas system used? Clean out all of it to be sure there is no restriction, even a small one can cause problems. Measure and line up your gas block so it is exactly dead center on the hole in the barrel. I can't see you gas block all that well, but is it adjustable? I don't think it is, but I'm not going to assume. If there is an adjustment knob or lever it may need to be turned the opposite direction, or could be caught between selections. Make sure your gas tube isn't pinched near or inside the barrel nut or upper receiver. Let us know?
Highandright  [Member]
3/15/2012 7:21:28 PM
Ok I will take the block off to check for any blockage or alignment problems. How much should I open the hole up. Do I need to get really small changes like number drills or is 1/64 bigger ok.
Highandright  [Member]
3/15/2012 7:22:45 PM
and no its not a adjustable gas block
USMC2147  [Team Member]
3/16/2012 12:41:46 AM
Opening the hole where? On the gas block? On the barrel? I would NOT mess with the barrel, this could have adverse effects on your accuracy and could cause fouling issues in the gas port. I would just start with proper alignment and get a gas tube cleaning brush to make sure the tube is clear. Try again and let us know what you find, and if re-aligning the gas block helped.
d13s3l  [Team Member]
3/16/2012 2:01:15 AM
no need to even be thinking about messing w/ gas port yet.

more than likely, gas block misalignment.
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