If by 'better' you mean reliable cycling, try an aftermarket recoil spring. It will be a little stiffer than the stock spring. I installed one along with a full length guide rod right from the start, and haven't regretted it. My GSG cycles anything I feed it. Usually that means thunderbolts/golden bucket/m22, since they are half the price of minimags, so that makes them 'better'. Sure they're a bit dirtier, esp. the m22 I've seen, but I clean my guns after every range trip, so no big deal.
The spring has paid for itself many times over, with what I've saved from not having to buy the high impulse ammo. About 5k rounds through it at present, the only failures have been the occasional bad primer. Oh well, that's rimfire.