375 RUM Build

To prove your point, in 2017 Mitch Fitzpatrick won the King of 2 Miles competition with a .375. At that time using a prototype 400 grain solid made by Brian Litz. We currently know that bullet as the 400 grain solid Berger released last year.
 
There was a question about Free bore for the 375 RUM and this may help.

The RUMs all normally have close to .200 thousandths freebore because they were designed for Spitzer bullets and also designed to manage the pressure better. The big Weatherbys have much more freebore because of the powder charge and the use of round nose bullets for dangerous game.

The 378 Weatherby (A 375 cartridge) has close to .500 freebore and the 460 Weatherby has .756 freebore. This may sound excessive, but considering the bullet shape the freebore is used up fast with these bullets and what is left is to keep pressures manageable.

With today's Low drag bullets, .200 to .250 freebore is plenty if you don't encroach on it. Many feel that freebore is the enemy of accuracy, Not true. It is a plus for velocity and with proper loading these cartridges can be extremely accurate.

Long range hunting shooting is aided by velocity and freebore definitely aides velocity. All of my big wildcats have generous amounts of freebore and are very accurate. (Well under 1/4 MOA).

Yorke-1 375 BME has .391 freebore to get the most capacity and manage the pressure. (It is also almost the same as the 378 Weatherby)

I would recommend a minimum of .200 freebore for the 375 RUM to get the best performance from this cartridge. My 416 Buff has just under .400 thousandths of freebore and has shot 400 grain Spitzer's to an all time best group for me of .034 Thousandths @ 2700 ft/sec and no pressure.

Don't crowed the big Magnums and you will be amazed at what they will do.

Just my opinion

J E CUSTOM
 
Many feel that freebore is the enemy of accuracy, Not true. It is a plus for velocity and with proper loading these cartridges can be extremely accurate.

Exactly my thoughts as well. My Weatherby wildcats are all extremely accurate and still have the factory freebore. They both are very forgiving and easy to load. The best attribute is that the freebore keeps the pressures down.
 
I have a 28 inch barrel too. RL 33 really makes the 230 sing. I just wish 33 wasn't so temp sensitive. Oh well, it's still one of my favorite rifles, but then again, they are all my favorite.
 
One thing I learned. Factory bolt is pretty lose. Once you shorten the stop and it comes back further it will bind if you work it fast. Work around is to close with your thumb on the striker. If I had a do over I would use a different action or a ptg bolt
 
One thing I learned. Factory bolt is pretty lose. Once you shorten the stop and it comes back further it will bind if you work it fast. Work around is to close with your thumb on the striker. If I had a do over I would use a different action or a ptg bolt
What difference does the PTG bolt make?
 
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