I just picked up my new S9 from the dealer. I field stripped it in the shop and everything looked good on 1st inspection. No bad castings, burrs or bad machining found. I'm getting ready to prep clean/lube for break-in. I spotted a sale on a 200 round qty. of Winchester 9 mm 115 gr. FMJ ammo. The only thing is, it is steel case ammo. Would this steel case ammo be recommended or suitable to do break-in of my S9? Or should I use brass cased ammo?