Hello, I own a model 63-3 four inch with very low miles on it .I am having trouble with non firing shells.Roughly two in ten and do not come from same cylinder. I lean towards federal and Winchester high velocity medium grade shells. The same shells have no issues in rifles.I have tried cci mini mags with no problems at all. Also i tried my standard velocity cci with 2 of fifty non fires.I see a nice strike on shells ,is this a ammo issue? I only put standard vel through my k22s and 35s so i have no barometer on other guns. Thanks