I've got two uppers with muzzle devices pinned and welded on.  My old Harbor Freight drill press was damaged years ago, I never replaced it and have been looking for an excuse, now I've got one.  That and I really don't want to ship them to a gunsmith when the task is relatively simple.  So I don't want to break the bank and could probably make do with another HF, but is there anything out there a little better at not much more money?  And I'll need a vise, which I never had on the old press.  Regular vise or XY?

Every one I've ever seen removed that didn't look like rats ate it off was done in a mill.

Not discouraging you from buying tools, just sharing my observations. However if I was going to attempt the drill, I would use a grinder to remove the weld to the greatest degree possible before I went to work with the drill.

A good old fashioned drill press works great.  Like an old 500 lb South Bend drill press.  Surgically drill right into the pin.  Use a carbide or HS bit.  Go slow

A vice isn't really needed, I've done it with a simple V-Block.

I would look at a bench top mill/drill way better then any drill press and you can mill with it.

180-degree / 109% disagree.  A solid old fashioned drill press will focus energy down and hold it tight to drill right into the pin.  A mill is a sideways tool with very little vertical travel or torque.

Never ran a Centre-cutting end mill cutter,eh

My boss did his FN w/ a hand file and Dremel. Didn't look pretty, but the device was getting tossed, anyway.
Offered to do it on my mill, but he's...impatient.


Yup.
Not to mention, a loose fitting pin can "break loose", once the weld is compromised, and start spinning or cause the bit to go off-center and possibly snap.