Toying with idea to convert one of my .375’s to .375 WBY. One is a 24” Winchester one a 20” Winchester. Obviously more velocity from the 24” but will there be an increase in the 20”? My 20” shot factory 300 A frames at 2400 and been to Alaska a couple times. Or just make my extra .300 RUM into a .375 RUM? Or just leave it all alone and go hunt with them

I have a .416 RM so really it would be about trajectory

This is a boring answer, but just go hunt with them and have fun.

The Wby 375 is a fine round, but only has an 11% usable volume advantage over the H&H. Using the old wildcatting rule of thumb that it takes 4% more volume to gain 1% more velocity at the same pressure, that gives the Wby an about 70fps advantage, too little to care about IMO. Everything else comes from simply increasing the pressure, and you don't need a special chamber or brass to do that. If H&H brass fireformed in 375 Weatherby can take an extra 10K psi in a rechambered H&H barrel they can survive it in their original form too.

Bob

I wouldn't bother - there's little point between the two, and no point in changing one to the other ... it's a .375, hunt with it, it'll do the job. if you have the itch, sell one, buy a ruger

if you held a gun to my head, do the 24" one, you'll have better difference

quote:

Originally posted by Omnivorous_Bob:
This is a boring answer, but just go hunt with them and have fun.

The Wby 375 is a fine round, but only has an 11% usable volume advantage over the H&H. Using the old wildcatting rule of thumb that it takes 4% more volume to gain 1% more velocity at the same pressure, that gives the Wby an about 70fps advantage, too little to care about IMO. Everything else comes from simply increasing the pressure, and you don't need a special chamber or brass to do that. If H&H brass fireformed in 375 Weatherby can take an extra 10K psi in a rechambered H&H barrel they can survive it in their original form too.

Bob

I can't talk to the Math but I've chrono'd Weatherby factory loads with 300g Partitions through my Rem XCR II with a 24" barrel. They are right around 2750 fps. That's as significant an improvement as the 300 Win Mag over the 30-06. It allows you to leave that 300 Mag or 338 Mag at home since it will reach out and touch something at past 400 yards.

Keep what you got.

Re-chamber the 24 inch one or re-barrel the 20 incher with a lighter weight tube. I'm not into short barrels and with the Weatherby I sure wouldn't want to give up velocity.

Or just build a 375 RUM.

FWIW, my 375 Weatherby tops out a 300 grain TSX at 2760ish. My RUM easily pushes the same bullet at 2800fps. If that matters...

With a healthy dose of RL-17, my 375 Bee pushes a 300 NAB out of a 24" barrel at 2779 fps.

Sell them both and buy a 416.

quote:

With a healthy dose of RL-17, my 375 Bee pushes a 300 NAB out of a 24" barrel at 2779 fps.

[/quote]They are right around 2750 fps. That's as significant an improvement[/quote]

My point was just that, loaded to the same high pressure, even the old H&H will get over 2700fps. As a reference Quickload shows a pressure of 65.1 psi to get 2770 with RL17 in a 24" barrel. The H&H shows 2706 with RL17 at the same pressure with the same 300 NAB. The 375W is a great round, but when it comes to ballistics there is no free lunch. (And for reference, my all around rifle for 20+ years is a light short H&H that "only" does 2450fps with 300NPs)

EDIT: What Todd said!

Did you read my post ? I have a .416 RM so that not an issue. Killed many Buffalo with it but I like to mess around but maybe I’ll keep these as is

quote:

Originally posted by Todd Williams:
Sell them both and buy a 416.

You could look at a 375 RUM. Same bolt face. Mag may need work, depends on the rifle. With a Remington I think all you would need is an RUM mag box. Significant power increase over the H&H.

quote:

Originally posted by gunslinger55:
Did you read my post ? I have a .416 RM so that not an issue. Killed many Buffalo with it but I like to mess around but maybe I’ll keep these as is

quote:

Originally posted by Todd Williams:
Sell them both and buy a 416.

Sure I read your post. But ...

1) You are looking to get more power from one of your 375's. If you need more power, a 416 makes sense since there's nothing a 375 can do that a 416 can't do better, albeit with a bit more recoil.

2) You have two 375's in the same chambering so I figured you have no problem with having multiple rifles in the same caliber. Adding another 416 should be no problem. Maybe a Rigby this time if you want to have 2 rifles in the same caliber, but different chamberings. With the Rigby, you'll have lower pressure than the RM, and have the ability to load it up to WBY specs if you want.

3) My comment was a bit tongue in cheek anyway!

Maybe you need a .338 or a 9.3 of sorts!!k You have a gap to fill there!

Got a .338 lol. I guess I’ll just leave as be unless I am really bored. Got tons of rifle and projects that never seem to get finished anyways I’m sure that’s a common issue…

quote:

Originally posted by Todd Williams:
Sell them both and buy a 416.

Got one. Good on Buffalo

quote:

Originally posted by Omnivorous_Bob:

quote:

With a healthy dose of RL-17, my 375 Bee pushes a 300 NAB out of a 24" barrel at 2779 fps.

They are right around 2750 fps. That's as significant an improvement[/quote]

My point was just that, loaded to the same high pressure, even the old H&H will get over 2700fps. As a reference Quickload shows a pressure of 65.1 psi to get 2770 with RL17 in a 24" barrel. The H&H shows 2706 with RL17 at the same pressure with the same 300 NAB. The 375W is a great round, but when it comes to ballistics there is no free lunch. (And for reference, my all around rifle for 20+ years is a light short H&H that "only" does 2450fps with 300NPs)

EDIT: What Todd said! [/QUOTE]

Omnivorous_Bob,

Do you mind sharing the QL of RL-17 for the H&H at 65.1K psi? I've a new .375 H&H with a 22" barrel and have yet to fire it, but have loaded 77 grs of RL-17 behind the 300gr TSX. Then 235 TSXs,250 Sierras and 270 TSX's are all loaded with CFE 223. But I'm curious about that RL-17 load you mentioned using RL-17 for the 300gr NP. My last .375 H&H (Browning) had a 26" barrel and would make ~2700 fps from Hornady's 300gr BT. That was long ago before RL-17. I used RL-15 and IMR 4320, both giving about the same results. I currently use RL-17 in my 9.3 x 62 exclusively, so am quite familiar with it.

Thanks,

Bob
www.bigbores.ca

Bob, here's what I got for both the NP and 300 accubond. My favorite load is the 300 NP with 70.0 of RL15.




Bob

Thank you very much Bob. I greatly appreciate this!

That's impressive from a 24". 1gr less in my 22" might mean a loss of up to 100 fps, but may, on the other hand, be compensated by the longer 300gr TSX. It is seated about 1/8" deeper. I believed RL-17 would be best in a .375 H&H with 300 grainers since it has been near a miraculous performer in my 9.3 x 62 shooting the 286 NP and 320gr Woodleigh PP, giving 150 fps more from the 286gr at less apparent pressure than RL-15. Then, it was tested for me by a friend with QL, as also the 320gr Woodleigh PP was.

Thanks again...

Bob
www.bigbores.ca