John Polk
Well-Known Member
A 300/340/375 Weatherby case would be very easy to convert to 358. This would make a fine rifle and an easy conversion. More powder capacity and more velocity.The birth of the 358 PRC
375 ruger necked down to 358
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Overkill338
Well-Known Member
I would rather have the option to use standard length LA.
John Polk
Well-Known Member
John Polk
Well-Known Member
You may have to seat your bullet very deep so that it protrudes into the case displacing powder.
Overkill338
Well-Known Member
I did the .30-375 Ruger wildcat in 2009. Mine was for the purpose of using the belt size for powder space. Max COAL of 3.34" just like the .300 Win Mag. I formed it using the .300 RCM die.
John Polk
Well-Known Member
Aren't .358 bullets longer than .300 bullets to obtain the same ballistic coefficient?
Overkill338
Well-Known Member
It works that way for any bullet as you go up.
rbTanzan
Well-Known Member
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Mram10us, what are the dimensions and neck length on reamer diagrams for your 338/375? How would it compare to a 338 PRC?
Didn't come with a diagram. I'll have to look and see if it's a standard reamer or modified.
I'm ignorant to the 300 and 338 prc, but from looking at specs it looks like a 30-375 and 338-375 ruger to me. I'm probably wrong
Kiwi Greg
Well-Known Member
Yep within a few thou here & there to what was done years ago to the 375 Ruger case
7-375 Ruger, 30-375 Ruger & 338-375 Ruger
Overkill338
Well-Known Member
I want to see if a .458 is possible. But with no belt, how would you headspace it?
I shot a 358 Norma Magnum for many years.
Max speed in a 26" barrel for me with 225gr Nosler Partitions was about 3030 fps. Could hit 3050 fps easily, but primer pockets would not last more than 3 firings. The lack of good long range bullets and good quality brass with strong primer pockets is what made me abandon the cartridge. But it was a hammer on deer for sure.
I also still own a 338-375 Ruger. It pushes 250gr Berger Elite hunter bullets at 2980 fps in a 26" barrel. That's quite a bit faster than 338 Lapua factory ammo offerings with 250gr bullets.
If a person wanted to neck down the 375R, I would highly recommend going to 338 vs any other bore size. I'm sure it would push 35 cal bullets very fast, but the selection of decent bullets is very limited.
Max speed in a 26" barrel for me with 225gr Nosler Partitions was about 3030 fps. Could hit 3050 fps easily, but primer pockets would not last more than 3 firings. The lack of good long range bullets and good quality brass with strong primer pockets is what made me abandon the cartridge. But it was a hammer on deer for sure.
I also still own a 338-375 Ruger. It pushes 250gr Berger Elite hunter bullets at 2980 fps in a 26" barrel. That's quite a bit faster than 338 Lapua factory ammo offerings with 250gr bullets.
If a person wanted to neck down the 375R, I would highly recommend going to 338 vs any other bore size. I'm sure it would push 35 cal bullets very fast, but the selection of decent bullets is very limited.
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375 Ruger case capacity is 99gr H2O.
300/340/375 weatherby all basically have the same capacity as the 375 Ruger. All between 98-100gr H20.
Wouldnt be gaining anything there...
Now if you used the 378 weatherby, that would be a significant increase in case capacity. But then a person would need a Lapua size action for the .580 case rim diameter
John Polk
Well-Known Member
You could set the bullets further out to gain case capacity.
