drilling and threading gas block to make it adjustable

[obsessiveshooter]

I searched for info on this here to no avail...

How hard can this project be? I have a drill press, drill bits, a tiny budget and a need to tinker and do things myself. Low-pro gas blocks can be had all day from ebay for $10 shipped.

I have ordered a steel gas block but should I do aluminum instead? AL is easier to drill, but won't a steel set screw lock up against the AL eventually?

My idea is that I can drill it from the muzzle end so that I can adjust it w/o removing the freefloat rail. Maybe even put in a knurled knob screw instead, like the Colt GB.

This will be my first AR, and I want it to be useful for 3gun.

Are there any things you all would advise me of before I do this? I am aware that there might be something I am overlooking...

[P.E. Kelley]

Hmmm, first AR...correct??? Please do yourself a BIG favor and shoot the snot out of it as it is, before you concern yourself

with little things like adjustable gas systems.

Do you have a good trigger in it?

Barrel free floated via a proper handguard?

I am the old guy here on the forum and just hate to see new guys get wrapped-up on little stuff when the 300 pound gorilla

is more practice time.

Merry Christmas.

[MarkCO]

First, take Patrick's advice.

Would go with steel, aluminum fails and gas cuts too soon.

Would go with one that seals well too.

It is not hard to drill a GB and put in an adjustment screw. In fact we did small batch of our gas blocks that way and I have one on my .450Corvette. BUT, one that remains adjustable is not easy to do without some well planned maintenance or a very good design. Currently, the SLR and the Colt appear to be the leaders to me, but long term adjust-ability is still unproven.

Edited December 13, 2014 by MarkCO

[Mark Gale]

How hard can this project be?

Much harder than you could ever expect with a drill press, drill bits and a tiny budget.

[obsessiveshooter]

Mark Gale, care to elaborate? Drilling a hole and threading it is not difficult.

[obsessiveshooter]

MarkCo, I have been thinking about this long-term adjustability thing. From what I have read, carbon builds up and locks the set screws in place. I'd like to set it and leave it, but that seems to be a sure thing for eventual lockup. Would it be a matter of removing the set screw every X number of rounds and running the threading tap through the hole again to clean out the threads? Also, do these screws tend to move in and out durin initial use?

[MarkCO]

Regular cleaning, like every few hundred rounds, is about the only way to keep them clean and clear. Depends on how close your tolerances are as to whether they move or not. Even then, if you have threads in the gas stream, they will get gas cut unless you use expensive materials. That will require readjustment at some point, and then kind of just not worth the effort. There are solutions out there, but expensive to manufacture which is why they are not produced.

[ac4wordplay]

Hmmm, first AR...correct??? Please do yourself a BIG favor and shoot the snot out of it as it is, before you concern yourself

with little things like adjustable gas systems.

Do you have a good trigger in it?

Barrel free floated via a proper handguard?

I am the old guy here on the forum and just hate to see new guys get wrapped-up on little stuff when the 300 pound gorilla

is more practice time.

Merry Christmas.

Pat knows what he's talking about (and so does MarkCo).

Best,

ac