So far all the howtos on pinning on an ar15 front sight gas block follow this basic pattern:

* Put the barrel nut and handguard cap on the barrel.
* Put the front sight base on the barrel making use of something to get the gas port in the block aligned with the hole in the barrel.
* Immobilize this in a jig of some sort and/or vice grips.
* Mark where the pins will go.
* Possibly using a second jig, place under a drill press, clamp in place, and drill one hole.
* Ream the hole and constantly check to make sure the taper pin drops in as far as it should, then tap it into place using an appropriate punch and hammer.
* Drill and ream the other hole and install the other pin.

In all the howtos, the really tricky parts are getting the FSB correctly aligned and keeping it there. More recently I realized the following:

* To drill the FSB's gas port, the manufacturer must first drill a hole opposite where the port is supposed to go. Then a smaller bit can descend through the hole and drill the actual gas port.
* A lot of barrels now come pre-dimpled, one dimple right on the other side from the gas port.

Putting these together I thought I could get things secured with less chances of stuff slipping out of alignment by threading that larger hole in the FSB and then put in a setscrew. That way the FSB will stay put and likely not bump out of alignment. Further clamping or jigging for the drill press would then be much easier to set up and deal with. After drilling, reaming, and pinning on the forward part of the FSB, I'd remove the set screw and drill the rear.

Do my premises make sense? Is my approach of using a temporary set screw to simplify things likely to work?