I've been shooting Remington brass for over 30 years and have never had any problems with them. I suppose, if you wre going to shoot competition, you might have to weed through a batch, but for hunting purposes, they work fine. The big difference would be thickness from lot to lot. I usually keep lots seperate for that reason, but with my 7-30 Waters, I use fireformed 30-30 brass picked up from wherever I can get it. For the most part, I keep seperated by brand, unless I start see problems, then I will weigh each one and seperate by weight.