Clem Bronkoski
Well-Known Member
Today was some more load testing with the 6.5 CM and 270 WSM. I first did a ladder test with charges from 40.0 gr to 42.6 gr of H4350. I got a nice node between 42.0 and 42.6 gr. The single target below is my aiming point at 100 yards to shoot through my chrony. All 9 shots had and extreme spread of 0.9"! Velocities ran from 2472 up to 2618 fps. I had some additional rounds loaded with 41 gr and 42 gr and shot them off at the other target at 200 yards. One 5 shot group and one 3 shot group with the 41 gr measured 1.13" and .87" respecfully and one 5 shot and one 3 shot group of the 42 gr came in at .85" and 1.0". These groups correspond to my ladder test. I'm almost positive it will shoot tighter with a charge of 42.5 gr. At this point I consider this rifle a true 1/2 MOA rifle.
The 270 WSM on the other had didn't fare out so well. Three loads of 73 gr, 74 gr and 75 gr of MagPro shot 3 shot groups of 3.2", 3.5" and 2.6" at 200 yards. Even though the 75 gr shot the best today I was getting some pressure signs via a sticky bolt and a ring around the case head from the bolt face. My previous outing this rifle shot 1" with a 72 gr charge. So I'll stick with that.
The 270 WSM on the other had didn't fare out so well. Three loads of 73 gr, 74 gr and 75 gr of MagPro shot 3 shot groups of 3.2", 3.5" and 2.6" at 200 yards. Even though the 75 gr shot the best today I was getting some pressure signs via a sticky bolt and a ring around the case head from the bolt face. My previous outing this rifle shot 1" with a 72 gr charge. So I'll stick with that.