Rebuilding my 375 RUM

[Tikkamike]

I have decided its time to start a new project. Going to rebarrel my 375 rum to a 375h&h. I currently have a 26" stainless tube. I ordered a #5 benchmark 5r 10twist finish at 25". Iay take it down to 24" I'm not 100% decided on that.going to put a harrells brake on it and the rest will be the same as it is now other than a new .25 recoil lug.

 

[benchracer]

Re: building a 375 h&h

Cool project! I love my 375 H&H. I am really curious, though, as to why you decided to back it down from a RUM to an H&H. Seems like most folks would say the RUM is a better cartridge. I don't personally have any experience with the bigger 375's. I would be interested in your thoughts on this...

 

[Lefty7mmstw]

Re: building a 375 h&h

I love my 375 h@h too, and I too am a bit perplexed as to why you are taking out a 375 rum for an h@h. I'd think of downloading a bit first.

 

[ancient]

Re: building a 375 h&h

Admittedly I am a novice at the technical aspects of either cartridge. I can say this though, most people in Zambia have .375 H&H as their heavy callibre rifle. This could be as a result of it being marketed more......What is the major difference between the two?

 

[Greyfox]

Re: building a 375 h&h

I'm a big fan of the 300H&H, owning a Whitworth Express rifle for over 30 years. Shot a bunch of game from Impala to Cape Buffalo on a few trips to the Dark Continent.

 

[Tikkamike]

Re: building a 375 h&h

The reason I'm doing an h&h are I love that cartridge. Its been one of my favorites since I was a little kid reading about them. Also I wanted a shorter rifle and the h&h at 24-25" is pretty impressive. A lot of people may not know this but the h&h is very under loaded in the reload manuals.... the h&h is a 100 year old cartridge and there are a lot of old rifles out there in that chambering so they typically only load them to 50k-55kpsi for safeties sake. And all newer cartridges go to 60k-65k psi. If you load an h&h up its no slouch. I have seen 2800+ out of a 24" h&h with 270 grain bullets. Now the ultra is obviously faster especially with a 26" tube. But I wanted something shorter... why not an ultra with a 24"? Because an ultra really shines with a 26+. I have owned 2 ultras one in a 24" one in a 26" the 26 in my opinion is the way to go because at 24 it doesn't have enough burn time and hasn't really passed the h&h by much yet. Also this is my serious elk rifle. Probably my 500 yard rifle shooting 270 tsx. The h&h will do exactly what I want for its intended use. I love the ultra and I'm going to build another but my plan for the ultra will be a heavy barrel and a 28"+ tube throated to shoot 350 grain cutting edge bullets. Or something along those lines. I might do another one in a hunting rifle I'm not sure but that's where I'm at right now.... can't have too many 375's

 

[Outlaw6.0]

Re: building a 375 h&h

After reading your last post, I think you've got it right. The RUM needs more than 24" to shine (IMHO). A 28" tube throated for 350CEB's should be REALLY fun to play with, one can't help but wonder about the performance potential .

I too have read many African adventure stories beholding the .375 H&H (I still own most of Capstick's books). I had a wild hair many moons ago of building a 500NE on a Ruger #1 frame.... the 458Lott beat me to death so the 500 idea died


Better start a build thread


t

 

[HARPERC]

Re: building a 375 h&h

I had a wild hair many moons ago of building a 500NE on a Ruger #1 frame...

Similar thoughts in my head, only 50-140 Sharps on a large Falling Block Works action, got brass got dies, had action almost in hand-got divorced instead. I believe the NE and the Sharps are the same basic case. If I did it now it would have to be very heavy to be manageable. Never met a .375 H&H I didn't like, same with the .300. I definitely want to watch modern loads take shape, keep us in the loop. I know you guys have a couple in your group so no need to start from scratch.

 

[benchracer]

Re: building a 375 h&h

The reason I'm doing an h&h are I love that cartridge. Its been one of my favorites since I was a little kid reading about them. Also I wanted a shorter rifle and the h&h at 24-25" is pretty impressive. A lot of people may not know this but the h&h is very under loaded in the reload manuals.... the h&h is a 100 year old cartridge and there are a lot of old rifles out there in that chambering so they typically only load them to 50k-55kpsi for safeties sake. And all newer cartridges go to 60k-65k psi. If you load an h&h up its no slouch. I have seen 2800+ out of a 24" h&h with 270 grain bullets. Now the ultra is obviously faster especially with a 26" tube. But I wanted something shorter... why not an ultra with a 24"? Because an ultra really shines with a 26+. I have owned 2 ultras one in a 24" one in a 26" the 26 in my opinion is the way to go because at 24 it doesn't have enough burn time and hasn't really passed the h&h by much yet. Also this is my serious elk rifle. Probably my 500 yard rifle shooting 270 tsx. The h&h will do exactly what I want for its intended use. I love the ultra and I'm going to build another but my plan for the ultra will be a heavy barrel and a 28"+ tube throated to shoot 350 grain cutting edge bullets. Or something along those lines. I might do another one in a hunting rifle I'm not sure but that's where I'm at right now.... can't have too many 375's

I agree with you about the H&H being underloaded. I started experimenting with it this last spring using 300g bullets and H4350. I am loading it a lot longer than standard, as well. With 300g Hornady BTSP, I achieved 2720ish from a 25" barrel and Hodgdon BOOK LOADS. With 300g CE's, I got 2760+. I was getting zero pressure signs and felt that there was still some throttle left, but didn't push it because I had already exceeded what I was hoping for.

I haven't developed accuracy loads for those yet, but my next round of testing will include 320g CE's and 350g SMK's with RL-17. If I can run the 320's @ 2650-2700, I will have a formidable long range elk rifle. I will use the SMK's for less expensive practice to develop my skills far enough to take full advantage of the rifle's capabilities. I am also keeping a watchful eye out for the Berger .375 that is supposedly in development. I might switch to that for my practice bullet, depending on how it works out.

Though I recognize that it is nowhere near the top of the ballistic heap, I am a big fan of the ol' H&H. I am convinced that, loaded to modern levels with the latest components, the H&H has a lot more potential than people believe it does. I firmly believe that both the H&H and the 375 Ruger have the ability to punch well above their weight class (or case capacity) when fed the right powders and bullets.

I am glad to know that there are others thinking along similar lines. I am very interested in your H&H build and I look forward to reading more as your build progresses.

 

[Tikkamike]

Re: building a 375 h&h

I agree with you about the H&H being underloaded. I started experimenting with it this last spring using 300g bullets and H4350. I am loading it a lot longer than standard, as well. With 300g Hornady BTSP, I achieved 2720ish from a 25" barrel and Hodgdon BOOK LOADS. With 300g CE's, I got 2760+. I was getting zero pressure signs and felt that there was still some throttle left, but didn't push it because I had already exceeded what I was hoping for.

I haven't developed accuracy loads for those yet, but my next round of testing will include 320g CE's and 350g SMK's with RL-17. If I can run the 320's @ 2650-2700, I will have a formidable long range elk rifle. I will use the SMK's for less expensive practice to develop my skills far enough to take full advantage of the rifle's capabilities. I am also keeping a watchful eye out for the Berger .375 that is supposedly in development. I might switch to that for my practice bullet, depending on how it works out.

Though I recognize that it is nowhere near the top of the ballistic heap, I am a big fan of the ol' H&H. I am convinced that, loaded to modern levels with the latest components, the H&H has a lot more potential than people believe it does. I firmly believe that both the H&H and the 375 Ruger have the ability to punch well above their weight class (or case capacity) when fed the right powders and bullets.

I am glad to know that there are others thinking along similar lines. I am very interested in your H&H build and I look forward to reading more as your build progresses.

My dad and I both have a good amount of experience with the h&h and i have found that you are right on the money. Brian Jeppson Shoot-Long | Long Range Rifles, Long Range Shooting is just about finished with a 375 ruger I had him build for my dad. I got some pics last night and it looks sweet. I will post some when its in hand. The 375 diameter is by far my favorite for shooting big game.

 

[Lefty7mmstw]

Re: building a 375 h&h

Most 375 h@h rifles can be run a bit harder than book, but I'm at 2700 fps with a 270 or 2550-2650 fps with a 300(depending on load)so I don't think I'm that far off the top anyway. Plus, if I ever do get over to Africa to do some game thumping I don't want the empties sticking in the rifle. I am using I 4320 in my rifle and though it is a hell of a powder it isn't temp. stable so the last few % aren't on the table.
I think I'm doing fine with an 8# rifle with no brake and a striaght 6x scope holding sub moa with a 300 grain barnes tsx. The 270 speer may be on the table though one day as the last group from that pill was a cloverleaf.
In any case good luck with your build; it's one heck of a round.

 

[Tikkamike]

Re: building a 375 h&h

I will be shooting the 270 TSX hopefully. I think it will be a lot of fun

 

[J E Custom]

Re: building a 375 h&h

Sounds like you know what you want.

I have a few comments about the 375 H&H (Not bad at all).

The old H&Hs were designed to use Cordite Powder (Long sticks that were counted instead of
being weighed) Hence the long case and shoulder angle.

One of the problems of "ANY" dangerous game cartridge loaded hot is pressure in high temperatures
The H&H had lots of body taper helping extraction in these conditions.

The 416 Rem is a good example. With factory loads and velocities it can become edgy and hard to extract in high temperatures. Remington Wanted to meet or beat the old Rigby with lots more case capacity and the results were High pressure at high temperature.

I have one and love to shoot it but in hot weather I decline and move on to something with more case capacity loaded at the same velocity. This avoids any problems that could cause injury from
a bad *** animal intent on ruining your day.

I personally would stay with the Rum And load down to H&H velocities rather than load the H&H
hot. There is no doubt that with modern powders you can get more power from The H&H.

I am the last person to try and talk someone out of building what they want, so don't take this
that way. I just wanted to share My experiences with Some of the old cartridges that were designed
for much lower pressures than the modern rifles/powder can produce.

Most of the older cartridges were designed for less than 50,000 psi compared to 65,000 psi of modern
rifles and brass.

Anyway, have fun on your build. (And build what you want in spite of what we say)

J E CUSTOM

 

[benchracer]

Re: building a 375 h&h

I agree completely about using an H&H, or any DG cartridge, with max loads in hot weather. When I finally am able to take my rifle to Africa, you can bet I won't be taking my max handloads along. It doesn't make sense to do so given the application.

However, for use in North America, I don't see any reason to leave that much performance on the table. Keep in mind that I have well exceeded book performance using BOOK loads with a substantially longer COAL and about .080 from the rifling. Given those specs, there is no way that I am even running hot loads yet. Moreover, I have done this using a very temp stable powder.

I say all of that only to point out how much headroom there is in this cartridge in factory form before book loads are even exceeded. I haven't even tried to load up to more modern pressures yet.

At this point, my theory regarding this cartridge is that the factory 3.6" OAL is the big performance thief. It limits case capacity and prevents effective use of powders of the proper burn rate to get max performance with 300g and up bullets. It seems to me that being limited to faster powders tends to limit performance with anything heavier than a 270g bullet.

I strongly suspect that the OAL limit of 3.6" has a lot to do with the long standing practice of stuffing the H&H and similar cartridges into modified 30-06 length actions, rather than putting it in a proper magnum length action. When the H&H is housed in a proper magnum length action, a lot more of its potential can be unlocked without pushing pressures, simply from the gain in effective case capacity afforded by loading long.

Everything I have looked at so far tells me that, even relative to already low SAAMI pressures, the .375 H&H is underloaded as it is. Simply loading it to a length that doesn't eat up case capacity and using powders with the right burn rate for the bullet weight and available case capacity does a lot to bring this cartridge alive.