Anyone else tried the G&P L Mags (46rd ones)?
Seem to be getting some very hot shots for 1-2 BBs then settles down. 285, 276, 263, 260, 258….
My TM STANAG mags give 266fps +/- 2fps.
Leaving the mag for a couple of mins and trying again gives shots around 266 which is what I was expecting...