Prep for pinning a gas block

[Col_Crocs]

Is it still necessary for me to dimple my stripped barrel to secure the GB for drilling and reaming or will the set screws' hold on the barrel's surface alone be enough to get the job done?
My barrel did not come pre-dimpled and would really rather not unless I really have to.

[mark5pt56]

It will be fine, I've done it the same way--besides not that I've had an issue with port alignment-it gives you a chance to set it in the right spot to be sure.

[kartoffel]

Disclaimer: I've never installed an AR gas block taper pins from scratch.

... but if you wanted to do a real through job, here's how I'd do it:
1) Position the gas block without the gas tube in place. Peek inside the gas tube hole and make sure the hole is aligned right.
2) Stick some modeling clay dams on each end of the gas block.
3) Fix the gas block temporarily with some cerrocast.
4) Fixture the barrel, and using drill press or end mill, drill starter holes for the taper pins thru the block and barrel in one shot.
5) Ream the pin holes by hand with a taper pin reamer. Blow all the chips out and lightly oil.
6) Test fit 2 lengths of taper pin stock and mark each end a little bit proud.
7) Cut your taper pins to length.
8) Pound 'em home.
9) Observe how much is left sticking out each end. If necessary, remove the pins and grind them a little shorter, or (carefully) dress the ends while on the rifle.
10) Knock the cerrocast off.

Overkill? Probably, but if I had full access to any kind of gunsmithing equipment, that's how I'd do it.

[Col_Crocs]

Thanks for the responses! Appreciate it.
kartoffel: I will be using the BRDE Pinning jig to drill and the BRDE dimple jig to align the gas port.

[comp1911]

I like to dimple for alignment and it gets the setscrews seated flush in the gas block. Hope my jigs work well for you. :)

[Col_Crocs]

That was actually the plan until I realized your dimple jig also makes a very good alignment tool since the guide holes are actually the same size as the GB's gas port. So the plan now is to locate dead center and reference mark accordingly. :D Thanks for the great products!