i have owned 2 echo 249 full and para an a&k mkii and 2 ca m249. they all shoot but ca is by fare better quality.i just ordered a bew ca 249 from apd and picked it up last week shoots amazing and noticed they did some improvements on the gear box seem stronger then there previous models and have a rest window for the anti revers. huge amount of room for any type of battery you want im running a 10,000 mah 7.4 lipo yes 10k and i also run a 6300mah 11.1 lipo and i shoot a min of 1-3 box mags a game and never hand my battery die in a game