Thanks to all of you for your varied advice . I shoot A400,s and have never had a problem, 1, always read the manual for any semi automatic shot gun, FIRST, as there are various loading and unloading procedures, 2, clean the gun prior to firing, 3, lightly oil the working parts, 4, pull the barrel through to ensure any surplus oil is removed and the bore is clear of obstruction,5, most importantly clean after firing, wether 50 rds or 500 rds carbon is produced by burning powder, which will over time corrode, and reduce the efficient working and condition of your gun!! Good luck, and keep moving!!