22 Adapter questions

[Johnny l.]

To add to what Red and Ratter said above- The rifling for a standard .22LR is usually 16 turns per inch. The rifling for the .223 is usually 7,9, or 12 turns per inch in a M16/AR-15 type rifle. The bore diameter for a .223 is about .002/.003 bigger in diameter than it is in a .22 barrel. So what you have is a .22 bullet going thru a .223 barrel that is too big in diameter and with a rifling twist that is too slow. The result is that the bullet is not as accurate as it could be. O.K. for casual plinking, but you won't get very good accuracy. Also, that very dirty .22 powder residue gets blown in your gas tube. Shooting several .223 bullets might clean it out. Might not. Before I got my dedicated upper, I used an M261 Adapter. It worked well. The only limit was the 10 round magazine. I think Black Dog Magazines has fixed that. I did change out the gas tube on the .223 upper when I got my .22 upper just to be on the safe side.The .22 upper is a straight blow back operation, so no worries.With the adapter, even at 25 yards, the accuracy was not so good. at 100 yards, there was no accuracy.

This is a little off thread, but - I had Accuracy Speaks build me a dedicated 22 upper. I can now shoot out to 100 yards (and more), and hit anything I aim at. It doesn't take any longer to trade upper receivers than it does to open up the receivers and trade bolt carriers. The dedicated upper is real pricey, however in the long term has paid for itself in ammunition savings.

Good Luck. Regards, Johnny Lawson