peepsight3006;
We've got two .308 Normas, one built on a 98 action that has a 23 5/8" barrel and one built on a tang model Ruger 77 with a 24" barrel.
As well, we've got a .300Win. Mag in the safe in a Ruger #1 with a 26" barrel and a really long throat, so one can make the cartridge pretty much "all it can be."
Speaking in broad terms, I've done some experiments with all three using the same powder, bullet and primer combinations and the Normas will usually come close to equaling the velocity of the .300WM using a grain less powder.
To my way of thinking the Normas are a bit better fit in a 98 action or the Ruger 77 tang model, or perhaps better said, required less tinkering on my part to get them to feed nicely.
I've worked on a couple .300WM built on 98 actions and they needed more work to make a nice fit and feed situation.
As I have no pressure testing equipment I can't speculate on pressures.
Somewhere in my reloading notes I did measure the volume difference in the cases and it isn't really much, perhaps a couple or three grains, but not much in terms of percentage increase.
Lastly, we've always used necked down and blown out .338 brass or necked up and blown out 7mmMag brass because for years Norma brass was quite tough to find up here and very expensive when it was found.
The ironic thing is that using those cases results in a neck roughly equal to the neck length on a .300WM, so I've lost all the advantages of that long neck.
I will say we've not really noticed any practical difference thus far with the shorter neck, but we don't shoot 1000 meter match or anything with our rifles and might if we did? I can't say for sure.
Hopefully that was some use to you. Good luck on your upcoming hunts.
Regards,
Dwayne
