I've been reloading 223 cartridges for my Mini 14 since January of this year. This past week I bought an AR 15. I took it to the range and the grandson and I put about 70 rounds through it. I saved the brass, as I usually do. When I cleaned them, decaped the old primers, and then cleaned them again to remove the lube, I noticed that an average of 5-6 out of every 50 had a noticeable split in the neck or the beginning of one. I culled these and threw them away. I know this is about the fourth time to reload these cases. I was just wondering if this is normal for reloading 223 cases (I do not max my reloads, usually about the middle) or if the specs on the AR 15 are causing it? In other words, with the AR, should I reload the once fired cases only one or two times then throw them away?