i have the mk1 rifle 2, about the mag not fitting.... i had the same problem, the hop up(it is adjusted by the little hole at the top of the gun right b4 the barrel is extended out) anyway,look and see if u see a goldish-bronze color that u can fit an allen wrench in2(thats the hop up), u will need a flash light 2 locate it because its small if u see it right away and its in the center of the hole, then that isnt the prob, if u dont see it, it means that it was loose and is stuck back so the mag wont go in, and if the mag is in it wont come out, trust me ive tried pulling it, and the part connected 2 the hopup snapped and i basically had 2 get all new parts