I used to think semi LMGs were unpractical too. The price point for me makes the M249 undesirable, even at the 8k-10k price points I've seen them at. I own 2 semi auto MG42s and a full auto. Full auto is great fun and all but mine is chambered in 7.62x51 which means I am blowing $50 a belt for either 3 seconds of ripping it or 30 seconds roughly for bursts. One semi is 8mm, and one is also 7.62x51. They are fun in the sense you have a MG42 and they are quite accurate. I do not have an immediate shooting area I can exceed 100 yards but I feel like they'd preform well farther than that. I can't think of a better phrase but the semis have a better "return on investment" I.E shooting a full 50 rounder on a semi, taking time with your shots lasts 2 minutes or so, even slamming the trigger as fast as you can lasts up to a minute. I think my last outing with the full auto I no joke blew $500 in ammo and the entire running time was maybe 2-3 minutes during a 8hr range session with family and friends. I rarely shoot the full auto for myself anymore unless I am trying to fix an issue or just want to pretend I'm at Normandy for a belt or two. Also you can get 3 semi 1919A4s, maybe MG42s if you find some of the 5k ones, maybe DP27s if you have someone build them for you, for the price that shop was selling the one M249. Hell you can even get 3 fightlite raptor uppers for that price and those are a-lot more flexible since binarys, FRTs, and super safeties exist.