Tried the following magazines
KWA 360 HICAP (does not fit)
AIM 360 HICAP (does not fit)
MAGPUL P-MAG 120 mid cap (Perfect Fit)
STAR MAGPUL 75 Rds (Fits)
MAG (Short VN style) 120 rds
S-Arm M4 160 rds (Works - just need to slide a little to the side)
LONEX M4 FLASH MAG (Actually Works - just need to slide a little to the side)