7 WSM Development

[vermeire]

I know the the WSMs are dead, especially the 7. I inherited a Bansner built on a Model 7 and I'm partial to .284 projectiles so I'm working up a load. Last week my son and I ran shots over the chrono and got the ladder table below. 73.4 is the max book charge. I started to see primer flattening at 74 grains but there was no bolt stick. The flattening was bad enough at 74.6 that I didn't fire them in the later strings. I'm thinking I should load some additional rounds at 71.5-73 and be a little more precise with my charges. For these loads I was using a digital scale and have since decided that the beam scale is a better choice. I'm not going to really have much seating depth adjustment due to the short magazine length. If I get consistency like the 71.6 & 72.2 (1 shot didn't register) loads give I don't think I'll care. I don't have a target from the ladder due to only having 200 yards to shoot; I don't think there would have been enough variation.



At this point I'm asking for opinions or suggestions and to confirm my thoughts. I appreciate any input.

 

[Axlrod]

I would either shoot 3 shot groups at 200 or shoot the powder ladder at 600 or more. The target is what will give you useful info. Velocity is just not going to point to an accurate load.


I was into the 7 WSM about 12 years ago. Had the best results with Reloder 25 and 180 Gr. Berger HVLD's It really was the best of the short fat cartridges of the time. Lack of good brass pushed me to the 28 Nos.

 

[Highvoltage1]

If you’re flattening at 74gr, I think I’d load 73.5, 73, 72.5, 72, 71.5 and shoot them. I’d make the 73.5 my rifles max charge with that powder/ bullet combo. Don’t stress the velocity thing, Let the target talk. Sounds like you know your max charge and your max oal. I’ve been using the ocw method for load development and it’s helped me a lot and saved me a bunch of reloading components. I shoot it at 100 yds max. Best wishes!!

Ps my buddy killed a nice bull this year with his 7wsm and a 175 elite hunter, went 20 yds.