MACs are a beast on brass
That's more or less normal. The springs need replaced about every 6000rds. The Ingram or M10 (commonly referred to a "MAC") was available in 9mm & 45acp. The latter was quite popular due to the effectiveness of suppression. The 45acp variant was ~1100rds/min weapon. This was part of the advantage of an M10. Ingram designed it as an ambush/counter-ambush weapon. It's not a "precision" tool. It was a "get them all, let God sort it out" tool. There were several suppressors available. The Sionics weighed over a pound. Heavy by today standards. There was an M11 in 380acp. It was a bit smaller than the M10. In the latter years there was an elongated model of the M11 in 9mm. If you own a M10 you don't reload. Do the math, the magazines hold 40rds You will empty one in 2.4sec. Unless you own a Star machine you'll be "yanking a handle" for a long time. Before 1986 the MAC could be purchased for under $300.00.