Hey reloaders, I have about 300 pieces of Hornady Brass. They are measuring 1.237 to 1.248. My Speer manual says trim to 1.280. I know that if there a bit short , it's ok. But are these to short? Should I trim them all to the shortest length , that would be easier than trying to sort them all. And finally if I trim them all to 1.237 and make them 1.570 COL as my manual says, will they still have the same velocity ?