Virgin brass doesnt always expand to full chamber length on the first firing.
Softness or degree of annealing left around the neck/shoulder area also affect how much your shoulder pushes back.
Some of the BEST brass you have is once fired in your gun.....for that brass use only your collect die...it will chamber excellent.
Btw...was all that brass you collected from one gun and not several....THAT could be the culprit if it came from several.
If you love your 270 get a body die to go with the keep collect.....its fantastic.
