not really...about the only thing you can do is load up the chaos mini arena mut and set it to use only firemines. The other thing you could do is add them yourself in a map. But its the code will spawn at random the 3 different types of ammo for the claw2 (fire, proxies, needles) as it was never built to have that ability to allow the kind of control your suggested. We may think about doing that for our next version in U3 (if its deemed apporate we could have a selection to elminate the ammo types like we have a selection today to limit the wepaons types)