joesmoe_6

By the way I did the same thing with my Armalite .308 and adjusted the 100 yard offset to 11.50 inches, I was within 3 inches of the bulls eye at 500 yards

I had the competition as a FYI to everyone I was shooting 750 Grain AMX 50 Cal BMG. I sighted the rifle in at 100 yards. I had it dead on. I the ran my balistics calculations for a 500 yard zero using the same load. This showed at 100 yards the bullet would be 7.5 inches igh. I then used a laser bore sighter to set the point of impact at 100 yards to be 7.5 inches high. I was 10 inches low my first shots at the competition. I then adjusted the scope up 1.8 MOA. I was the almost dead on the bulls eye. I shot a 3 shot group of 1.25 inches

7.5" high from center of target at 100 yd zero ant going to get you to center at 500yds. It's between 7.5 to 9 inches of drop just to 300yds with a 200yd zero. Suggest you start at 12.5 to 13.5 minutes up. The ballistics software shows a 7.5 inch high flight path at 100 yards for the ammo that I am using. I set the scope up by using a laser bore sighter and placing the cross hairs 7.5 inches below the laser dot.

I have other gas blocks and 1 more armalite gas tube. I wiil try that this week end if it doesnt rain

Thanks everyone for the responses. I thought I had that right. I chronographed my loads and have an average fps measurement. I am only shooting for groups not for exact bulls eyes.

I have a question regarding setting up for a 500 yard Competition. Can I use a ballistics program and enter the following parameters Bullet Weight, BC , sight over bore , etc and use 500 yards as the sight in distance. Calculate a firing solution based on the criteria I've given and use the 100 yard rise value to set up the scope for the 500 yard shot. By that I mean at 100 Yards the bullet is 7.5 inches high. If I set up my scope so that it shows 7.5 inches high at 100 yards will I be right on at 500 Yards ?

I wish that I had a four inch group I was shooting at a 500 Yard competition On Sunday and I was hitting the traget next to my lane that was 15 feet away from my target.

Thank you all for the responses. The problem is definitely with upper receiver as I have tried a different upper receiver on the lower receiver and it functioned flawlessly. I think the problem lies with the gas block leaking. I say this due to examining the gas tube at the gas block interface and I see carbon on the tube in back of the gas block towards the receiver

When you replaced your gas block, did you also replace your gas tube? I re used the gas tube from the original handguard and gas block I was reading through this thread, and wondering if this was a complete rifle that Armalite shipped to the customer, or if it had been messed with in some way... Anything at all changed from how it was delivered from the factory... Need to know what exactly (and all-inclusively) was changed from the factory rifle. Then, start looking there first... 1) I bought a Stripped AR 10 Lower receiver and assembled it my self. 2) I bought a Complete AR 10 Upper Receiver including bolt and charging handle. 3) I replaced the handguard and gas block with a troy battle rail free float hand guard and low profile gas block on the Upper Receiver

Did the rifle malfunction when in stock configuration ? Or did you change the hand guard before firing it the first time ? I did not fire it in the stock configuration Do you still have the stock components ? Yes Try loading one round in the magazine & see if ,after firing the one round , that the bolt will lock open after last shot . The bolt will not lock back with a single round in magazine Try all the magazines you have . I have tried 5 different magazines all do the same thing

Thanks everyone for their responses Answers to questions are as follows If its a stock AR 10 rifle , just talk to Armilite & may have to send it back. Rifle should function with 168 match ammo. I have modified this rifle so that is not an option If its been altered , what was changed ? I put a troy battle rail free float hand guard and low profile gas block on the rifle Did this just start or has it happened since day one. Started the first time I fired the rifle What other ammo , if any , were also tested in this rifle & what were the results. I have tried several brands of ammunition in this rifle Thing that I have done to correct this problem. 1) Lubed the hell out of the bolt carrier and upper receiver 2) Checked Gas Block Aligment miced out position of gas port versus barrel sholder and the low profile gas block. 3) Verified gas port size ( .086 ) 4) Used the standard buffer and spring. None of the above has resolved this issue

Thanks everyone for the response. In answer to your questions I have a rifle length gas system on a 20" barrel. I have tried the standard H3 buffer and have the same issue. I have lubed the hell out of the rifle. I am shooting Hornady .308 168 grain A-Max Match ammo. The magazines are new 10 round mags

I have an Armalite AR 10 B that is short stroking. It will not pick up a new round from the magazine after ejecting the spent case. I am using the standard Armalite Buffer Spring and Slash Heavy Buffer. Any ideas on what I can do to correct this issue ?

Should have been NY the gun unfriendly state

Hi everyone. I've been a member for a little over a month. I have really gained a lot of knowledge from the site and want to say thank you to everyone for the information that everyone has provided Thanks