Like Pugs, I initially got into the "Black Rifle" bidness, "just because", so for a long time, I owned just two in 5.56, a Bushmaster (purchased in 2007) and a Colt about three years ago.
Then Hatari got me into the "thumpers" so I built one using a Davidson Defense upper, a bolt from somewhere else and a lower from Palmetto (?) I also spent the "big bucks" and bought a Wyndham "Thumper" both in 450 BM. Even doing some hand loading for them with those mean looking bullets that look like a Phillips screwdriver head. But they also shoot Hornady factory with accuracy (see below three shot group at 100).
Bottom line is you can build these things for less than 500 bucks and they SHOOT. Besides, spending money on these hideous looking irons is like ordering a Yugo with leather seats..

[Linked Image from i.imgur.com]

A good principle to guide me through life: “This is all I have come to expect, standard lackluster performance. Trust nothing, believe no one and realize it will only get worse…”