AR gas block change

Kevin Stenberg

Well-Known Member
If a person is switching an A2 sight/gas block to a low profile gas block. Should he also figure on getting a new gas tube? Or (if he doesn't damage the old one) can the gas tube work with the new gas block?
 

358156 hp

At large, whereabouts unknown.
The gas tube can be reused. If you buy a replacement tube, it would be the same length anyway unless you change to a different length barrel.
 

Pistolero

Well-Known Member
Should be fine, assuming you get the tiny roll pin out cleanly, usually no problem.
Often difficult to get the pins out of the A2 front sight/gas block.
 

Ian

Notorious member
I'd replace the tube if it were me, the g.i. one is bent differently than a low profile one for one thing. Don't forget the roll pin on your order. Also dont forget to allow for the space of the front forearm escutcheon because low pro blocks are designed to work without them (under a free float handguard) and won't line up with your gas port with the escutcheon in place unless you make some modifications.
 

Pistolero

Well-Known Member
Make a roll pin insertion punch if you do not have on. Take a piece of about 1/4" steel rod
and drill a just barely oversized hole in the end, axially, to hold the little roll pin. HUGE
improvement in getting that little booger started. And you will not lose one or two in
the process, generally.

Bill
 

Ian

Notorious member
That'll be on his next order, along with the starter punch. He won't have much fun if we Kibbitz everything, now will he? :p
 

Ian

Notorious member
Yep, Hey-soose clips got that name for a reason. Hey-soose's last name is #%$&@à@AAAAAARRRRRGGGG!!!!
 

Kevin Stenberg

Well-Known Member
I have to order multiples of everything. I must have a nest of gremlins in my work area. Every time i turn around they move or take whatever i need next.
 

RBHarter

West Central AR
My experience is that because of the universal design fit of the AR/MSR that I had to allow the spacing for the fore end cap even with the low profile GB on a custom production heavy barrel .
The pins are tapered in the A2 sight from the butt left to right to get them out .
Clamp on GBs might be the best way as far as gas seal and net contact but are also the easiest to have not lined up .
Set screw GBs seal the port and generally fit no lube , no tools , contact slip fit . Most barrels will have a dimple that matches at least one of the generally 2 screws with proper alignment on the GP .
I have used a used gas tube but what a pita . I did find an accuracy difference with alignment tinkering with the gas tube for minimum touch . Buy the new one . The pin holes so far haven't been clean alignment but close enough and tight .

I have not repinned a replaced A2 to low profile GB but did stake/witness mark the dimpled screw .