To clarify for the OP, these don’t generally scale down the whole gun. Caliber conversions can be as simple as swapping the bolt.
You can also sometimes swap to a larger caliber. They make ‘conversion kits’ for the AR-15 that are functionally just most of a new gun. You can get those for a variety of calibers from 7.62x39 to .50 Beowulf.
It’s worked surprisingly well in the past, but I just put a heavy (H3) weight in to reduce recoil, probably won’t cycle .22LR any longer. And BTW, that heavy weight is a dream! My wife’s friend brought his stock AR to our camp and I was shocked how much harder it kicked.
Calibre conversion kits do exist. I think they could be for might be cases where people want to practice marksmanship with smaller calibers like a .22 https://en.m.wikipedia.org/wiki/Caliber_conversion_device
To clarify for the OP, these don’t generally scale down the whole gun. Caliber conversions can be as simple as swapping the bolt.
You can also sometimes swap to a larger caliber. They make ‘conversion kits’ for the AR-15 that are functionally just most of a new gun. You can get those for a variety of calibers from 7.62x39 to .50 Beowulf.
I have an easily swapable bolt that let’s my AR-15 shoot .22LR. Pretty nifty, though not quite as accurate since the bullet is .003 thinner.
I have never considered shooting a .22 out of a .223 barrel as a possibility. Very nifty!
Got this one. Only one on the market I know of.
https://cmmg.com/22lr-ar-conversion-kit-bravo-w-3-magazines-blk
Same bolt came in my Han Solo pistol.
It’s worked surprisingly well in the past, but I just put a heavy (H3) weight in to reduce recoil, probably won’t cycle .22LR any longer. And BTW, that heavy weight is a dream! My wife’s friend brought his stock AR to our camp and I was shocked how much harder it kicked.