A Colt upper? I wouldn't change a thing, but you would have to separate the barrel from the upper receiver, then remount the barrel and gas tube on a new flat top receiver. Probably more trouble than it's worth.
Keep that upper the way it is. Just buy a new upper.
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Posts: 13237 | Location: Central Florida | Registered: November 02, 2008
This appears to non Colt people easier than it looks. Colt in my memory only offered a few HBAR true `1/7 uppers about 20+ years ago. The issue you have is you can find HBAR A2 rifles and current uppers. The current uppers are cut with M4 feed ramps where the barrels are not. Non compatible!! In my opinion this is easier with aftermarket parts (non Colt). If not you will need to find an older flat top upper without M4 feed ramps from a older sporter blue label gun.
If you do decide to put a different (flat top) upper on the rifle, check the takedown pin first. My Colt A2 HBAR, which I no longer own, had the oversized takedown pin which is bigger in diameter than the "standard" takedown push-pin. You used to be able to buy an adapter for a few bucks that would let you mate a small-pin upper with the Colt big-pin lower, but I don't know if those are still available.
Posts: 7669 | Location: Idaho | Registered: February 12, 2007