Just got done annealing my 300 win mag brass for the first time for this rifle after the third firing. Using the templac on the inside of the neck it would burn up at about 10 seconds. About a second and a half after I would first notice the full red glow. I loaded some up and shot them. They shoot great as always. Great like 1410 yards first round impact and 6 more shots directly after on a 15" steel plate. So the accuracy is fine. I have my 100 pieces of brass sorted so half take .334 bushing and the other half take a .335" bushing. The shooting I was talking about we're the lot with the .334" bushing. Today I loaded the .335" lot and noticed how little resistance there was seating bullets. After a couple I tested the tension by pulling and twisting on a bullet and it was very loose. I pulled those bullets, resized the necks with the .334" bushing seated bullets. It was a little more resistance. I twisted the bullet in the casing and it moved. It was tighter than the .335 bushing but still moved. I tested a bullet from the other lot that was shooting alright and sure enough it would move too. A couple things I can think of, let me know which you think or if its something else. Did I over anneal it and there is no elasticity left? Does brass grow thinner at the neck with each firing and I need to drop down in bushing size? Does air temperature have to do with it? By steel wooling the outside of the neck before loading actually take off a little material? If I would have to guess I would say I over annealed it. If so is it unsafe to shoot? I was heating just the necks and quenching in water after. If so, how does it still shoot so well? Thanks for the help.