the bolt carrier is not rated for fully automatic fire and the barrel is not lined with chrome so it is going to go bad after 25,000 rounds instead of 100,000 rounds.
Thats sorta funny. If a barrel last 25,000 rounds thats impressive. I would think 10-15,000 would be good barrel life for a gun that gets popped off fast most of the time. I don't see full auto in my future. Plus it seems like a 1000 round case of ammo goes for $400 plus shipping these days. Twenty five cases (25,000 rounds) works out to $10,000.00 bucks in ammo not counting shipping or taxes. If I have that much scratch to waste on ammo to shoot targets and plink I can afford a two or three hundred dollar barrel ever so often.
And like you said I would be like most people and doubt I would shoot more than a case of ammo a year.