reccomended weight FPS

.12 70-230

.20 240-360

.23 365-400

.25 400-430

.28 435-450

.30 455-500

.43 500+

hope this helped, and fps is with .20g bbs and is lower with heaveier bbs (500 w/ .20 = 360 w/ .43 but accuracy is MUCH HIGHER) accuracy will greatly increase with heavier weight but bb speed will suffer and so will range but what is the use of range with no accuracy, and vice versa, so personnaly i prefer .25's for my DBOYS RK-06 AK74.