My father and I both got M2000's (mine camo kit [26/28" barrel, pistol and standard stocks], my father 18" defender version) . After a break down/cleaning 1-1/8 dram3 #8 would not cycle at all it would eject the shell but not push the bolt back far enough to elevate the next one in. We then ran the heavy loads, 150 #4 2-3/4, for a brake in and they cycled them like a champ. Back with 1-1/8 dram3 #8 and 7-1/2, still the same. On dissassembly of both m2000's i noticed rubbing of the action bar on the forearm and some marring in the blue finish on the mag tube, i sanded (240grit) some material out and polished the inside of the forearm and cleaned up the edges of the action spring removing some small berrs. And the same thing would not cycle. Contacted Stogger to see if they had a lighter action spring and was told no dice they only made one spring for the M2000. Then looking at the design and comparing it to other gas guns i came to the conclusion that the action spacer needed to go but found it near impossible to remove.
So i found the solution i cut a 1/2" off the stock action spring (after ordering a new action spring from stogger just in case, $10 shiped) and now it works perfectly with 1-1/8 dram 3 loads, i have not tried any 1 or 7/8oz as of yet.
-Travis