Or a 20mm, even better :D

Your dumb friend is half right, shortening a shotgun barrel would increase the spread. But that's about all it would do.

AR-15 uppers are getting crazy. I saw one that allows you to use muzzle loading black powder rounds, and one that turns it into a crossbow. Following this line of reasoning, it won't be long before we have an upper that hurls a rock.

The crossbow and muzzle loading uppers have been out for years. Recently I've been looking at the .50 BMG, bolt action and the AR57 uppers

I saw the AR57 upper at a gun show a year or two ago, and I was puzzled by why it would exist. You trade in the compactness of a P90 and the economy of 5.56mm for a bigger gun that shoots more expensive and harder to obtain ammo?

A guy at the range had a .458 SOCOM upper and he let me fire off a round. That at least makes more sense than the AR57.

The same sense on who would want a muzzle loader AR-15 or a crossbow upper on an AR-15 lower.

Some places may only allow black powder hunting or you may want to just shoot bolts. It may not make a WHOLE LOT of sense, but there's still a purpose. I can't figure out the niche of the AR57.

Maybe it's for people who don't like the look and feel of the P90 and if they have the money, they get the AR57 for shits and giggles.

It looks pretty cool, except for the empty magazine well.

I think it's pretty awesome that they used the magazine well as the new ejection port.

I didn't catch that but yeah that makes sense. What did they do with the old ejection port?

e: nevermind I just saw it from the right.