If your starting out, I'd say try out your highcap, as you should be getting one with your CQB(excellent weapon choice btw). When I started out to me highcaps were the best as they held more ammo. As getting more involved in the hobby I've been hunting for more realism in my game and I now run 10 King Arms M4 lowcaps(68rnds) of which I plan to mod to hold 30rnds.
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