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10/8/2011 10:32:45 AM EDT
I just put together a complete AR-15 Carbine upper, 7:1 twist with all brand new parts, including a lo-pro gas block. Function test was good. Went to go shoot.."bang"..once does not eject/cycle. I had to manually pull back charging handle to eject fired brass and load a round, so it fires one round at a time.   Any help on this would be great. Is this a gas issue? If so, how can I diagnose the problem? Thanks, Frustrated for now..
10/8/2011 10:43:06 AM EDT
[#1]
It sounds like a gas block issue to me because it would not be enough pressure to move the bolt back and possibly a issue with the gas tube and block not log Ed up. Also possible ammo issue if using under powered ammo. Buy am still new and sure many will be along to help.
10/8/2011 10:49:46 AM EDT
[#2]
That's what I was thinking (Gas Block issue)..Its brand new (gas block Low Pro and carbine lengh gas tube). The Ammo is Lake City 62 Gr. Steel core "Good Ammo".   Now I need to know how to diagnose the gas Block Issue.
10/8/2011 11:03:43 AM EDT
[#3]
This may seem like a stupid question, but the gas port was drilled in your barrel, right?  AND is there a chance the gas tube is installed 180 degrees off?
10/8/2011 11:07:15 AM EDT
[#4]
Did you check gas port in barrel before installing gas block.
10/8/2011 12:34:28 PM EDT
[#5]
I checked the gas tube when installed..it was not in 180 degrees off.  I do not remember checking the gas port on the barrel..  I will have to dis assemble and see. Thank you for the input.
10/8/2011 12:45:25 PM EDT
[#6]
What I do is measure from the rear edge of the gas port on the gas block/sight base to the rear edge of the gas block/sight base. I then measure from the rear edge of the gas port on the barrel back that distance and make a pencil mark on the barrel. That tells me the port holes are lined up. With the gas block/ sight base on the barrel I line up the rear of the block to the pencil line on the barrel. I then ensure the gas block/sight base is level before securing it. There may be an easier way, but that makes me believe the gas ports are centered front/back left/right.
10/8/2011 5:35:58 PM EDT
[#7]
***Problem found/fixed****  Turns out while I was trying to get the gas block pin started I had the gas tube correct.  I had trouble starting the gas pin and I guess the gas tube moved and I mounted it 180 degrees WRONG.  Lesson learned on that.. I'll start the gas block pin first and mark the gas tube (Black marker so its right side up). Function tested and fired GREAT!
Thanks again for all the help...
Happy AR15 owner
10/8/2011 6:58:02 PM EDT
[#8]
Can you or someone provide pics to the rest of us noobs?

Having trouble imagining how a block can get upside down on the barrel. Isn't there only 1 hole for the gas tube to go in to? And thats at the top right?


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