I have a DG M249 (A&K) and i have i question regarding fps. I connect my gun to my air rig (HPA) and the gun shoot at about 330fps at 100psi. I still have around 350fps at 160psi. I use o.20gr bb's and a 6.01mm inner barrel. I try 2 different HPA tank 3000 psi (both full) on 2 different chrono (X-cortech). But the fps dont want to go up what ever the psi are.
I test both chrono with other gun to be sure they work well so the problem are not the chrono. I also connect my air rig to my pistol (KJW G23) and i was only able to shoot around 205-215fps (using .20gr bb's) what ever the psi were at 100 or 160.
Is there anyone who know why ?