300 RUM build

[EMCA]

Hi guys.
A few months ago I was going to build a 300 prc, but I thought I want a big 30.
I have decided on a 300 Rum to shoot berger 245 or atip 250.
What do you think of this configuration:
-I want it to be heavy to mitigate recoil.
-32" barrel length
-1:8 twist
-single shot
I would like to reach more than 3000 fps with these bullets.
What barrel life can I expect?.
What speeds are you getting from something similar?
Thank you so much

 

[Carolina Hill Billy]

Hi guys.
A few months ago I was going to build a 300 prc, but I thought I want a big 30.
I have decided on a 300 Rum to shoot berger 245 or atip 250.
What do you think of this configuration:
-I want it to be heavy to mitigate recoil.
-32" barrel length
-1:8 twist
-single shot
I would like to reach more than 3000 fps with these bullets.
What barrel life can I expect?.
What speeds are you getting from something similar?
Thank you so much

300 rum would have almost the same case capacity of a 30-338 Lapua. You could do the improved version for even more capacity. I’ve had great luck with the BAT M for this sort of single shot project. It will fit in a McMillan A5 style stock with magnum fill. I think there’s an xl version nowadays to balance your 32” barrel. Good luck, it sounds like a fun rifle.

 

[category_theory]

I have 300 PRC, 30” barrel 1:9 twist and custom throat to get more case capacity and I’m launching Berger 245s w n570 at close to 3000ft/s…. From what I’ve read it seems pretty damn close to what a 300 rum would do for you and I can get factory ammo… not that I would . Also don’t most folks custom throat 300 rum anyway these days? The original Sammi spec seats the bullets fairly deep in the cartridge, no?

 

[EMCA]

The idea is to make a 300 rum with the right throat to get maximum powder capacity.
It would be something like a 4.100 "-4.150" ltc.
I don't know, I hope to reach 3050-3100 fps with a 32" barrel.
Before I wanted to know the opinion of people
Thanks

 

[mullmann]

A 32” barrel with a 245 and N570 should get you 3000 FPS easily. You definitely need a custom throat. Good idea going single shot. Even a 4” box won’t do what you need. In the pictures show a 215, 230 and 245 at 4.070. The bullet seated is my 300 RUM around 3.83. I shoot 230’s at 3050 with 86.5 grains of H1000 out of a 30” barrel.

If you shoot slow and don’t get the barrel really hot you can get 800-1000. If you shoot one right after another, especially with N570 you will shorten barrel life.

The great thing about 4.070 is it gives you the option to run 215, 230 and 245’s. Lane precisions rifles reamer is set up for 4.070. Dallas lane said 3000fps with 245’s and N570 is doable out of a 26” barrel.

Mark

 

[EMCA]

Thank you.
Something like this is what I want to build.

 

[Longtine]

My 300 RUM is a 28" proof. My 245's I shoot are 3.975" COAL. I use N570 and I get 3,052 fps average with a ES of 8 and .2 moa. Best groups at 1000 yards are in the 4" range. I will say this. Plan on a single shot. I highly suggest it. Cause after I have lost lost .028" of throat on 210 rounds down it. And that's mostly cold bore shots.

 

[4O6shootist]

Long barrel 300 norma imp will do what you want with less powder and better brass. 300 lapua improved is another option.

 

[Longtine]

Long barrel 300 norma imp will do what you want with less powder and better brass. 300 lapua improved is another option.

I totally agree with that statement!!!

I'm fixing to chamber me a 338 NMI 40 deg!

 

[Ebar48]

Another vote for a 300NMI. I went with the 35AW version. Bullet central makes sizing dies for it, and the reamer is available at JGS.

 

[4O6shootist]

Another vote for a 300NMI. I went with the 35AW version. Bullet central makes sizing dies for it, and the reamer is available at JGS.

This one? Dedicated 245/250 could use a lil more freebore. N570 makes freebore in abundance tho.

 

[DJL2]

I have 300 PRC, 30” barrel 1:9 twist and custom throat to get more case capacity and I’m launching Berger 245s w n570 at close to 3000ft/s…. From what I’ve read it seems pretty damn close to what a 300 rum would do for you and I can get factory ammo… not that I would . Also don’t most folks custom throat 300 rum anyway these days? The original Sammi spec seats the bullets fairly deep in the cartridge, no?

The original design for a 2.850" case with a 3.6" COAL is simply Fuddtastic... a great way to see just how fast you can shoot that 150 grain Core-Lokt or 130 grain Barnes TSX. It followed the Weatherby model with a looooong free bore to burn more powder without unsafe peak pressure. Sort of Remington's take on the .300-378 Weatherby.

ETA: that reminds me of a piece I read as a lad that I still remember well over two decades later for its tremendous stupidity... it was perhaps the first truly clear moment where my younger self realized that gun magazines/writers often publish "pushing products to pay the bills" or "don't really know shit, but I gotta eat" articles... basically ad copy with a by line. Young me didn't know a whole hell of a lot (I really wanted an M40), but I knew when I read that the author had built a "tactical" rifle in .300-378 Weatherby and selected a 130 grain TSX because he "knew it would range beautifully" that I had waded waist deep into bull shit.

 

[Ebar48]

This one? Dedicated 245/250 could use a lil more freebore. N570 makes freebore in abundance tho.View attachment 8221665

I am running the 35AW, not the AW2 (I attached my reamer print below), and if you shoot alex a message asking what freebore he has set up for the 250s he will pass that info. He has 3 freebore lengths tested. One for the 215/208 Bergers which I believe is the one you posted above. My reamer length which was setup for the 220/230s/will work with the 245s, and then one for the 250 specifically. Can’t recall the freebore for the 250 reamer off the top of my head but yea, it does have more than the print you posted.

This is my reamer:

 

[EMCA]

Guys, in the end I'm going to build a 33xc.
It seems that at further distances the heavy bullets work better with the wind.
If I don't like the caliber later, I have the option of a 300 norma barrel.
Thanks