7mm-300 Win Mag

[grit]

A 7mm Remington chamber is larger than a 7mm Weatherby. The Weatherby case is about .050" longer but it is all in the neck. The Remington case is longer to the shoulder and to the shoulder neck junction. I've been using Weatherby cases in my 7mm for many years. I trimmed the necks and fire formed the Weatherby cases in my 7mm Remington.

I'm curious, why?

 

[Edd]

I'm curious, why?

Why what? Why I used Weatherby cases? Because that is what I had. But maybe I got a benefit I didn't even know I was getting. Almost every comparison I see of the 7mm RM and the 7mm WM the WM supposedly has a lot more case capacity. That certainly isn't from external case dimensions.

 

[ssphunter]

I have done 3 so far and love them. We have well passed the throat life of some of the larger 7mm's like the RUM and STW. I prefer leaving the 25 degree shoulder. This makes the choice of dies easy. I use Redding comp bushing dies for a 300 win and simply step down necks by reducing bushing size until I am at the needed bushing for 7mm. I also feel there is some inherent accuracy from the 300 win case as we are seeing excellent accuracy from all 3 rifles. So I would leave the taper alone and keep it simple and also for easy extraction. We have done 9 twists and throated for 180 Bergers. The velocity is plenty good from a 28" tube with H-1000 for propellent easily in the 3150 to 3175 area @ 4000 ft.

Hope this helps to answer your origional posted questions.

Jeff

How many grains of H1000 are you using to reach this velocity?