Set screw gas block for hard use?

[crazymoose]

I'm putting together a rifle that will be used mainly for target shooting and some training courses. I'm not in a line of work where I'll need it on a daily basis to defend my life, but I want to make sure it won't crap out nonetheless.

I'll be using a low-profile gas block (looking at the Stag one) for a rifle length gas system with a rifle length FF rail, so the block will be exposed in front of the rail. I'm also buying one of the dimpling alignment tools so I can properly dimple the barrel to install the set screws.

My question is if I properly dimple the barrel and install the set screws (red locktite?), can I be confident that the gas block won't go anywhere, even if it gets bumped around or the barrel gets hot enough to melt the locktite (which I believe gives out at 250 F)? I hear horror stories of set screws loosening when the metal expands with the heat of firing. Urban myth, or legitimate concern?

Or should I just pony up the dough to have it pinned in place?

[LOKNLOD]

Have you considered shaving the FSB into a low-pro gasblock? It's free, minus a little labor, and it will be taper-pinned in place.

[Robb Jensen]

Either 'shave' the FSB or have a gunsmith pin a low profile gas block.

[crazymoose]

Have you considered shaving the FSB into a low-pro gasblock? It's free, minus a little labor, and it will be taper-pinned in place.

I would, but I'm buying it stripped except for the extension.

[Robb Jensen]

I would, but I'm buying it stripped except for the extension.

What I do is use an milling machine to mill a flat spot on the gas block and then drill it for a straight pin. Works well.

[Patrick Aherne]

Set screws suck; pin it or go home.

[Jim D]

I just got a lightly used barrel (M&P 15T) with the set screw only gas block.

Would it be worth while to simply drill into the barrel where the set screws make contact, so they are sunk into the barrel maybe 1/16", then loctite it....or have it pinned?

If the answer is pinned, is there anyone who comes highly recommended here? Or is this just a local gunsmith kind of thing?

Thank you.

[C4IGrant]

If you cannot pin the gas block (best choice), then the next best option is to dimple the barrel, rocket the GB in place and rockset the set screws in place. If you run the rail over the GB (to prtotect it), this is a second best option.

C4

[Jim D]

If you cannot pin the gas block (best choice), then the next best option is to dimple the barrel, rocket the GB in place and rockset the set screws in place. If you run the rail over the GB (to prtotect it), this is a second best option.

C4

Thank you sir.

[vicious_cb]

The gas blocks on the Mk12 mod 0 and mod 1 are not pinned in place. So yes people go into combat with set screwed gas blocks