See some AR15 carbines in this chambering, but no pistols. Anyone know of any? Also, does the .45acp upper require a modified lower? Dan

A lot of views on this thread.. but no info.

I don't have a clue, but i'm interested to see the answer!

Me too!

edit to add: - it might be easier on an AR10, since the .45 head size is the same as a .308 case.

.45 ACP uppers do not require a modified lower, but they do require a magazine adapter that fits in the standard magwell. There is a specialized lower called the AR45 that only accepts the .45 magazine without the need for an adapter, but it falls under the heading of nice to have, rather than being a requirement.
Almost all .45 ARs are based on the Olympic Arms bolt, which is blowback and fits in a standard AR15 upper. There are a few custom gas-operated .45 ARs; these use a custom bolt in a standard AR15 upper. To my knowledge, no one has ever built an AR10-based .45, nor is there any need to use the large action.

An AR pistol in .45 would be a custom proposition, but it wouldn't be difficult nor expensive to build.

Perhaps this is because there are tons of pistols available in .45?..

I have one on an AR-45 lower, 10.5 inch barrel, greasegun mags... one of the most practical weapons I own and couldnt see myself without one.Mines gas operated.



edited to add pic