bb jams, weight or manufacturer?
Recently picked up my first gun, a G&P M4. It came with a bag of .20g King Arms bb's, but since I play mostly outdoors, I picked up a bag of Bioval .25g's. Problem I'm having is that with the KA .20g's the gun shoots fine everytime, with the .25g Bioval's it almost always jams up the first few shoots, dry fires, double shoots, etc. Once I get it firing, it's usually ok for the rest of the mag, but when I have to change mags or if I'm sitting somewhere and don't shoot for an extended length of time, I run the risk of it jamming again.
Would this be a problem with the weight or just the gun doesn't happen to like that particular manufacturer, or something bigger? I searched the forums and Bioval doesn't seem to be a bad brand, plus most of the guys at the field I play at use them with no problems.