Masterpiece Arms MAC-10 in 5.7x28mm

comparing the 5.7x28mm to a 45 ACP is ridiculous come back in 115 years when the 5.7x28mm has been used in two world wars and countiless minor conflicts world wide. The problem that wll firsta rise is the 5,8mm is not a poular cal/cartridge in militaries world wide and will never be carreid nor used to such an extent as the 45 ACP. Then comparing a armor piercing round to a precut hoolow point bullet that wighes almost 200 grains more is ridiculus as AP rounds tend to do nthing but over penetrate human flesh. In fact actaul results aginst living tissue for the 5.8 mm is sorely lacking and will be 110+ years for now simply becuase its not what its cracked up to be. the round is expensive hard to find and hard to reload plus the only thing its supposed to e able to do is go through kevlar you know that bullet proof stuff that was invented in 1965 by Du-pont and tested in later taht decade for military vests and used commercialy in tires and fishing klines in teh 1970s...kevlar is thick,heavy and out dated as a ballsitic vast material so why is everyone yelling about a 5.7mm can defeat it...I have seen slow 9mm defeat vest of Kevlar IIIA ratings. really get a life and when a few billion rounds ahve been fired over a century and in world wide wars come back and then tell em about the 5.7x28 becuase now the average American cannot afford a pistol or carbine in that caliber.

Despite the obtuse looking grip I picked up one of these in a rifle format at a gun show recently.

The gun is quite accurate which is unsurprising given the barrel length.
With a stock and a forward grip the gun handles like a dream and given the more compact dimensions of the rifle (thanks to the smaller magazine) I would love one as an SBR.

It's unfortunate that 5.7 ammo is kind of rare and very pricey now, especially since there is a reasonably priced platform that can handle the round quite well.