Small hole upper on large hole lower ?

[JD Spanner]

Ok guys need some expert help on this one,i have a Colt HBar Sporter 20" with A2 upper would like to change the upper to a flatt top but the likelyhood of finding one with the large pivit pin hole is slim, when i try a millspec upper on top and push back on it to take up the slack i see the holes are not centered so if i was to just drill the upper hole the bigger size would the upper/lower fit be too loose or is the rear pin different too, any thoughts?
Thanks in advance for any help.

 

[CanAm]

There are bushing kits available. Very simple, just drop in.

 

[furet]

A large hole lower with a std upper requires an offset pivot screw, you will not get the push pin ease of use but it's no worse than your current screw setup.

 

[JD Spanner]

Any ideas where to find one ?

 

[furet]

Wolverine!!! see add at top of page

 

[JD Spanner]

thanks guys i'll check that out

 

[Leg]

Offset pin is the way to go.

The only manufacturer of large hole flattop uppers that I'm aware of is Daniel Defense. Wolverine carries their railed forearms so they may be able to bring in an upper for you.