berdan or boxer primed?

I am just getting into reloading and my dad had a box of surplus .303 British from when he was a kid. I was wondering if they are berden or boxer primed. They are stamped K50 and 7. I compared one to a commercial round and the primer on the commercial round was smaller in diameter (as far as I can tell) and the primer on the surplus round looks like it is made of copper and is relatively flat (compared to the curved edges of the commercial ammo primer) so if anybody could tell me if these are berden or boxer primed it would be great. Thanks

I believe K50 stands for Kynoch manufactured in 1950

The cartridge will be berdan primed and loaded with cordite.

Yes, Kynock, 1950. Quarter inch Berdan primed. Corrosive. I have reloaded cases with this size of primer, but it is hardly worth it, considering that .303 cases can be readily obtained.

Ok thanks, I thought they were berden but i just wanted to make sure. Their are only around 30 so its not a big deal.