I bought a new Bushy "Shorty AK" this afternoon and it came with a Colt 20 round mag blocked to only hold 10. The "block" was a bent piece of steel which I removed. Is returning the mag to 20 rounds really that simple?
The actual Bushmaster post-ban mags are not like that. Even the older ones weren't like that (the two-piece ones). Sounds like somebody temporarily blocked the one you have. (other than Bushmaster, that is)