A2 Gas Block Install

[78bronco460]

When you drill the gas block and barrel, do you ream the holes with a tapered reamer? I have 3/0 and 0 reamers, I think the 3/0 to start and maybe 0 to finish. The pins are .125" - .140" diameter.

 

[jeeptj19992001]

Yes, right to left.

 

[78bronco460]

Yes, right to left.

Thanks. I'm building a dissipator upper and don't want to use a clamp on sight.

 

[FrankenToy]

When I do this I use a 7/64" bit and just a 2/0 reamer (also R to L). Probably could get away with a 1/8" bit, but I think my drill press has seen better days. Ream until the pins are, mebbe, 2mm proud and lovingly tap them in with a punch.

 

[78bronco460]

When I do this I use a 7/64" bit and just a 2/0 reamer (also R to L). Probably could get away with a 1/8" bit, but I think my drill press has seen better days. Ream until the pins are, mebbe, 2mm proud and lovingly tap them in with a punch.

I used a 1/8” bit and drilled them by hand and then the 0 reamer. It worked fine. I used the Wheeler front sight tool to mash the pins in and it’s ready to go. I’ll run a couple heat cycles and check for tightness.

 

[78bronco460]

I used a 1/8” bit and drilled them by hand and then the 0 reamer. It worked fine. I used the Wheeler front sight tool to mash the pins in and it’s ready to go. I’ll run a couple heat cycles and check for tightness.

Finally got my flash hider today and it’s done…

 

[_stucky]

Rifle length gas system on a 16 inch barrel? I like it.

 

[78bronco460]

Rifle length gas system on a 16 inch barrel? I like it.

It’s really a mid-length gas system with a low profile gas block. The A2 gas block is just a sight. I tapped the gas port and put a 10-32 stainless screw in to hold the hand gaurd retainer.
The problem with a 16 inch barrel and rifle length gas
is the short dwell time can make for an undergassed system. It’s mostly just for looks, but I like the long sight radius.