I have this Colt A3 upper that was drilled to accept a large hole SP1 lower.

it was my first ar i bought during the ban (16 inch m4-gery on a SP1 lower)
soon after i bought it, i found an original sp1 upper and called it a success.

is there a method of returing it back to a small hole upper so i can do away with the easy to lose sleeve?

perhaps jb weld the hole and drill when cured?

or somehow weld a sleve in place?

any ideas?

What do you have to loose?



WIZZO

Quoted: is there a method of returing it back to a small hole upper so i can do away with the easy to lose sleeve? or somehow weld a sleve in place?

Loctite 638 or perhaps 640 sleeve retainer.  You would probably do best to ask Mongo, as he is an evil machinist and dreams of these sorts of things....

Assuming it was drilled correctly, this offset bushing should work - Link.

Quoted: Assuming it was drilled correctly, this offset bushing should work - Link.

I have the sleeve, just looking for a  way to make it a pernament fixture to the upper.

It gets tiresome having to look for it under the work bench everytime i clean.