Has anyone had experience with this round? If so how hard is it to neck down, velocities, and load data?

you should be able to neck up 270 WSM brass in a 300WSM F.L. bushing die with the appropriate bushing and a tapered neck expander. Use a 7mm WSM seater die for bullet seating. I would think using maybe a couple of bushings ( may not need but the one) using 300WSM brass shouldn't be a problem either. There couldn't be that big a difference between the 7WSM and the 7mm-300WSM so start with the starting loads for the 7WSM and work up. Good luck and good shooting!

Glenn

I don't have any experience with it but I thought this was a cool article. He lists reamer specs and velocities (though from a rifle).

http://www.ballisticstudies.co...e/7mm+Practical.html

This is based on the 300 Win Mag, not the WSM.

quote:

you should be able to neck up 270 WSM brass in a 300WSM F.L.

From his header he wants to neck the 300 Win Mag down to 7mm. The 300WM is 2.620" where as the 7mmRM is 2.500" so you will gain a bit more case capacity not a lot but some so it will gain a few fps velocity over the 7mmRM round.

The neck down of the 300WM should be very easy to do, I think I have a set of 7mmRM dies if I do I'll try to see if its as easy as I think it will be. Give me a few days to check it out and I'll let you know.

If I'm not mistaken, Sawcarver here on SP is shooting the 7mm-300 WM. (Not WSM)
Maybe he will chime in here?

-Mike

I'm sorry, I misread his post. Yes, Sawcaver has a 7mm-300WM.

Glenn

I sized down 2 cases this evening and they sized like a dream, I kept running the die down until it just kissed the shoulder and using Hornady spray lube.

Thanks for all the great info. I'm going to try this round. Thanks for trying the neck down Al!

Adam does shoot one. According to him it is a beast.
In a good way. Lol

Yes I have a 7-300 Win Mag. Currently I am shooting 195 bergers out of it just a fuzz over 2700 fps out of a 17.5" barrel. When I have it set up as a bench gun it is about 17lbs and recoil isn't bad at all with a Ross brake on it. It does have a bit of blast factor to it for those standing or sitting beside it and it is loud but its fun. Shots over a mile are do able with it for sure

Adam