Yeah. I own a KWA LM4 with an NPAS installed, and I can get into Ultimate Airsoft in Toronto just fine. The bottom line is, if your gun fires within the field limits, you can use it. Hell, if you had a Barrett sniper rifle that fired under 350, use it as much as your heart desires.
Primary: KWA LM4 PTR, Classic Army LWRC M6 A2, Classic Army G36E, AGM/Javelin MP44.
Secondary: KWA Mk. 4 1911, KWA Mac 11, Skeleton Sidearms 8" .357 revolver.