3 sets comparison....
1) 14.5 M4 PTW, KAC RAS setting
2) New upper, Noveske 12" from brother sailun412
, very good align with upper rail
3) prime GBB, Taiwan Madxxx Noveske 12" ...... not good
, higher.....
Need some new stuffs to make this new PTW upper looks coooool !!!