Can the receivers be interchanged? Colt .22 Rimfire Rifles are dedicated .22LR. The upper and lower cannot be swapped with non-Colt .22 rimfire rifles.
In other news, school is back in session and I finally broke down and ordered a Colt M4 OPS Tactical .22 Rimfire Rifle. These are unrelated, I like school and won't use student loan money for this purchase.
Not entirely familiar with that particular rifle, but if you're really interesting in picking up a new upper to multi-task the rifle, talk to an experienced gunsmith and don't listen to the official word from Colt. If I listened to that bullshit, I wouldn't be able to fire reloads in any of my weapons. Plenty of aftermarket companies make .22LR conversions for standard AR-15s, so it's entirely possible that the opposite is possible. Then again, you're talking about an entirely different set of chamber pressures, so who knows. Never hurts to ask.
