My MK18 is at 350fps. I use it outdoor and indoor no problem. If your indoor is 310, then it's not low enough to mather outside.
We used to play at 280fps outside in 2002 and the differance in range compared to the rare 400fps rifles was not that much. Back then, everyone was encouraged to play stock (280fps).
Vérificateur d'âge: Terrebonne