I own a full sized G&G m14.
I had a M130 spring installed, and that spring destroyed the stock gears after like 3 shots. I then bought a set of infanant tork gears and a high tork motor, , wasnt really thinking when i did it, but the rof was terrible, so went back to the stock motor and got reasonable ROF, I do plan on putting in a high speed motor soon, I also run on a 9.6 volt pack. i will point out that we had to cut several coils off the M130 spring to make the gun shoot 440 ish with a .2, so a m130 is probably just a bit to much spring, go a little smaller so you dont have to cut the spring.
I also use a systema bucking, a shredder nub and the stock hop unit, paired up with a real promy barrel and not the cheap madbull one.
This gun reaches and taps them pretty good and easily out ranges most of the guns i have went up against on the field.
Diesel did a good job for me with this baby.