I've been slowly acquiring components and equipment to start reloading for my #1 in .303 British. My question is, how important is it to not mix brands of cases when trying to develop a load? I've got a fair number of Federal, S&B and Winchester cases and a few random Kynoch and Imperial cases. Just for context, I'm thinking of using BL-2(C) to lob Hornady 174 RN's at .308 velocities.

I would sort the cases regardless of whether it is going to be used for target or hunting.
How can you load safely looking for pressure signs (loading to 308 velocities) when every brand of brass is going to give you different pressures?
Just buy a 308 if you want 308 velocities, load the 303 to 303 velocities and enjoy it for what it was designed, why push it? You'll just burn through brass anyway and have to start buying it to keep up with how much you're destroying.
I would load for the most accurate load you can and forget about maximizing velocity. Being accurate is way more noticeable than an extra 200fps.
https://www.chuckhawks.com/303British.htm
I don't intend to start at 80000 psi, I intend to start at regular loads and work up. I'll probably go with PPU brass as recommended and try out RL-15 and BL(C)-2 as the pressures tend to stay very reasonable in the manuals.
As to the .308 comment, I've had .308's before but I LIKE .303.
With a Ruger No1 you can load them to 308 velocities with absolutely no issues as long as you check your case dimensions when working up the loads.
However good brass that has been fireformed in the same rifle is a mandatory requirement for a project like that .
I haven't lost any brass due to high pressures in my Ruger.
Cat
I don't intend to start at 80000 psi, I intend to start at regular loads and work up. I'll probably go with PPU brass as recommended and try out RL-15 and BL(C)-2 as the pressures tend to stay very reasonable in the manuals.
As to the .308 comment, I've had .308's before but I LIKE .303.



























