I don't know about 50BMG but I can promise 45acp and 357 mag don't bother it. I don't shoot it with 22s because my wife and I tried this and one got stuck in it. Probably not a big deal, i just didn't want it to come shooting out the side after being hit with something else.
They make one specifically for smaller calibers.
I guess I could shoot it with my 30-06 and let you guys know what happens.