so i shoot a little bit the other day after installing some new scope rings to get sighted back in with the coyote gun. shot a batch of loads i put togehter a coupe months ago. i noticed some of the case mouths were cracked just at the tip down about a 1/16th of an inch or so. this is out of a same batch i shot a few weeks ago with no cracks. these loads are charged almost 2 full grains below max charge weight, bullets are seated around .0020's off the lands with no crimp. there were no flattened primers or other signs of over pressure. has got me a little stumped. i had these rounds out with me on some very cold days chasing coyotes this winter. they are hornady brass, cci br primers, sierra 60gr. varminters with 45.5 gr. of imr4350. is hornady brass a little more brittle than others? should i anneal these cases before i resize? like i said the first 10 out of this batch did not crack but the last 10 i shot this last weekend did. seems weird. the only change to anything was the the new rings on the gun. ???