I bought an XD-9mm and put 500 rounds of Winchester 115grain range ammo through it without any problems. Today, I used the Remington UMC 9mm ammo from Gander Mountain (yellow box of 250 rounds you see everywhere) and used all 250 rounds. However today I had several problems and I'm wondering if it's this ammo. The slide would not always open when the clip was done, about 50-75 times the emtpy case would get jammed in the slide, and a few times the gun just wouldn't fire a round. Do you think it's this ammo or any other thoughts? This is only the 5 o5 6th time I've ever shot in my life, but the first time I've had problems like this. Appreciate any help to the new guy!!!