- Joined
- Jan 22, 2011
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- 8,031
Got handed a little project today. I have a Colt AR-15 SP1, which is the "slick-side" or "slab side" lower receiver. I have a .22 cal upper, and a .223 upper for it. The lower receiver has the front pivot pin hole in the large option, I believe .3125 (not actually measured it yet). The .223 upper matches it, but the .22 upper has the small front pivot pin. I don't want to have two pins, and I know there are offset pins for this, but I am thinking of reaming or boring the pivot pin hole in the .22 upper to accept the same pin as the .223. That would be the 5/16" pin.
Anyone see a problem doing this? It appears that there is sufficient material to be safe and strong.
Anyone see a problem doing this? It appears that there is sufficient material to be safe and strong.