Shooting the 6.5 CM and the 270 WSM

[Clem Bronkoski]

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.

 

[Barrelnut]

Might consider trying H4350 in the 270 WSM also. WSMs don't usually need a slow magnum powder because of the short powder column in WSM cases. H4350 is the most accurate powder in my 300 WSM. You might loose a bit of speed but accuracy might go way up.

 

[Clem Bronkoski]

Might consider trying H4350 in the 270 WSM also. WSMs don't usually need a slow magnum powder because of the short powder column in WSM cases. H4350 is the most accurate powder in my 300 WSM. You might loose a bit of speed but accuracy might go way up.

Thanks Barrelnut. But H4350 was the first powder I did try in this rifle and it didn't work as well as IMR4350.

 

[Capt RB]

I just started using 4955 in my dad's 270wsm. He had a great load with h4831 but it was slower than my 270 win with the same bullet. The 4955 with the 145eldx seems to want to shoot at top end vs the bottom end for the H4831. For deer season He will be running that eldx @ 3225. He doesn't go far from the truck these days. If the rifle does shoot game I think it will be either me or my brother that does the shooting

 

[Alibiiv]

I've been having really good results with Alliant RL19 in both the .270WSM and the .270 Ackley. I found the Ackley to be finicky with the 150gr ABLR with the RL19 until I found the right load, and from there it was no going back.

 

[Clem Bronkoski]

I just started using 4955 in my dad's 270wsm. He had a great load with h4831 but it was slower than my 270 win with the same bullet. The 4955 with the 145eldx seems to want to shoot at top end vs the bottom end for the H4831. For deer season He will be running that eldx @ 3225. He doesn't go far from the truck these days. If the rifle does shoot game I think it will be either me or my brother that does the shooting

I've been having really good results with Alliant RL19 in both the .270WSM and the .270 Ackley. I found the Ackley to be finicky with the 150gr ABLR with the RL19 until I found the right load, and from there it was no going back.

I don't have any 4955 on hand. I might have some 4831 but that would be really old. I do know I have some RL-19 that I tried in my 325 WSM when I owned one. going to have to look at some data for that.