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Posted: 6/5/2010 4:32:39 AM EDT
| I am building a 12.5 SBR, using a BCM barrel and DD 9.5 FSP lite rail. The problem I am having is the gas block is touching the front of the forearm and i have no clearance between the drive rod sleeve and gas block, according to AA web site this unit should require no modifications. Should i break out the dremel tool or is there some other cause or solution to the problem. Anyone else having any problems with their AA piston builds. Thanks for your comments! |
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If the block isn't against the barrel shelf and is a little forward, it's not anything to worry about unless you find not enough gas is getting through. As Adams recommends there needs to be some relief between the op rod and the carrier key to not put extra abuse on the op rod which can cause it to break. I'd set the block just barely not touching the handguard, check to see there's some space between the op rod and key by pushing it rearward at the piston cup and go shoot. If everythings working as it should your good to go. If it's not, call Adams. |
| everything is tight! when the bolt is in battery and i assemble the piston it push's the bolt about an 1/8" out past the rear of the upper receiver and the upper and lower will not close. the front gas block it seems should be 1/8" forward to allow some play in the system but right now i have no play at all. |
| I have a AA FA 10.5 upper, made by AA, cut down from a 16 inch barrel. I have never been able to fire a complete 30 round pmag through it with my FA lower. I fire other uppers with my FA Lower with full joy. Dont understand why it stops after 8-10 rounds and always end up on an empty chamber. Any body out there with a solution? I have already sent it back to AA 3 times. Please help me out. |
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Quoted:
I have a AA FA 10.5 upper, made by AA, cut down from a 16 inch barrel. I have never been able to fire a complete 30 round pmag through it with my FA lower. I fire other uppers with my FA Lower with full joy. Dont understand why it stops after 8-10 rounds and always end up on an empty chamber. Any body out there with a solution? I have already sent it back to AA 3 times. Please help me out. Start your own post to get more responses and also post in the AA industry forum. |
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Quoted:
everything is tight! when the bolt is in battery and i assemble the piston it push's the bolt about an 1/8" out past the rear of the upper receiver and the upper and lower will not close. the front gas block it seems should be 1/8" forward to allow some play in the system but right now i have no play at all. With the gas block semi loose push the carrier all the way closed. Now insert the op rod untill it touches the carrier and stops. Now adjust the gas block position to give you about a credit card thickness between the block and the op rod cup face. Tighten gas block. Remove op rod and use a very small allen wrench to see if gas block hole lines up with gas hole in barrel. There is enough angle on the allen wrench to insert it through the gas block and into the hole. If there are any problems its possible the specs of the barrel or the kit are off. |
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