Hey, I bought a .625 pencil barrel from DD. I am trying to pick out a gas block. I already have an upper with a midwest industries SSG2 rail on it and I want to mount this under the rail.

I think the clamp on gas blocks are best but I can't fine one I am confident will fit under the rail. The DD and Vltor .625 both appear to be a tad too big(correct me?).

So I am thinking of this one, the PRI low pro gas block.

http://www.midwayusa.com/product/537497/pri-low-profile-gas-block-ar-15-lr-308-steel

My question is, with the pencil barrel, is it safe to dimple the barrel manually without a jig if I know what I'm doing?

Don't know if you can dimple a pencil barrel like this without danger.

Sure, why not. They drill slots in them for taper pins when installing fsb.

Good point. I just didn't want to start drilling without at least checking.