AR 15 Gas Block

dfletcher

Aside from snugging up against the barrel shoulder and lining the tube up into the receiver, are there any little tricks to ensure the gas port in the gas block is lined up with the gas port in the barrel?

Also, I bought a clamp on type GB (.750 ID) and the darn thing kept walking forward when I was at the range today. It's on a 7.62X39 upper, a little more recoil, but I think the thing should stay in place. I see 3 basic styles of securing the after market gas blocks - a clamp on (clam shell) type with horizontal screws, a clamp on with 2 separate straps running under the barrel and a set screw type. Which holds best?

I'm thinking of the 1913 clam shell type on the far right: http://www.model1sales.com/item-detail.cfm?ID=BPGB04&storeid=1&image=gasblock.gif&CFID=32374660&CFTOKEN=26992511

Are there any after market GBs that use taper pins? I'm kind of liking the idea of a steel pin securing everything in place.

Mobuck

I've seen the recomendation of drilling a dimple for the set screws. On the clampon ones, I would try some heat resistant locktite.

gsmyth64

I usually just level the upper in the vice, and then use the level on the gas block.

yachtdave

If you use a spary cleaner with the tube attached and spray into the tube on the reciever end you should see the spray in the barrel. If not your not lined up.