I have played a few times on the speed ball field with my A-5, I don't use a stock on the marker because I like to get it nice an tucked in close.As far as using an A-5,if it has an E-grip I don't see whey you can't.And being hit with a flat-line on on the speed-ball field your opponent will now it.You might want to try a drop forward or what firemedic had suggested.