Okay REALLY need help here with model injecting & polyco

[Beastman]

Okay here the deal, i posted a battlerifle before, and some asked me to make one from the ar so we can put it into the game. well i did, problem though i have too many polys, i need to shave off some to get this into halo. i have tried doing this a number of ways and my regular ways like meshsmooth with iterations of 0 arnt working. so is there anyway to cut down the poly count, im using 3d max but if there is a way in another program i will try to import it to that and then go from there. but this is very important, if anyone can help me out it will be GREATLY appreciated. thanks