375 RUM Build

[Doublezranch]

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.

 

[J E Custom]

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

 

[Doublezranch]

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.

 

[Whitetail312]

Do any of your RUM's feed out of an extended Wyatt's mag or are they all single fed?

 

[Doublezranch]

I have a Wyatt's box for my 300 RUM. I load the 230 Berger at 4.0 COAL

 

[Whitetail312]

I have a Wyatt's box for my 300 RUM. I load the 230 Berger at 4.0 COAL

I think at a 4.0 COAL I can get some good velocity out of the hammers!

 

[Doublezranch]

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.

 

[Orange Dust]

I second the Wyatts center feed box. They really make shooting longer VLD type bullets much easier.

AND PTG makes bottom metal that actually fits the magazine, if you're interested.

 

[Whitetail312]

AND PTG makes bottom metal that actually fits the magazine, if you're interested.

What COAL is the mag?

 

[Orange Dust]

What COAL is the mag?

A shade over 4". It will also fit the 3.85" wyatt's box I have on my rum, but it is too long in the back. Works anyway and solved the feeding problem you will ha e with factory bdl. Fairly inexpensive too. Seems like it was 125 or so.

 

[Doublezranch]

I use mine as a single shot.

 

[Whitetail312]

I use mine as a single shot.

I've considered it, but being a hunting rifle I would prefer at least two more rounds in the box. I know it isn't necessary

 

[Orange Dust]

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

 

[Whitetail312]

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?