The .375 Remington Ultra Magnum, also known as the .375 RUM is a .375 riflecartridge introduced by Remington Arms in 2000. The cartridge is intended for large and dangerous game.
It is a beltless, rebated rim cartridge created by necking up the .300 Remington Ultra Magnum case to .375 caliber with no other changes. Factory loadings are less powerful than handloads for the cartridge. Remington factory loads push a 300 grain (19 g) bullet at 2760ft/s (840m/s), producing 5070ft·lbf (6.88 kJ) of energy. A handloader can increase the muzzle velocity of a 220gr bullet to 3321ft/s (900m/s), and develop 5800ft·lbf (7.9 kJ).
General information
The intended use of this cartridge includes hunting large, thick-skinned game. It is powerful enough to kill any land animal and, with its high velocity, can do so at fairly long ranges. One should note that such performance comes at the price of a heavy recoil: in a sporting-weight rifle of ~8lb (3.6kg), this cartridge can produce a fierce 80ft·lbf (108 J) of recoil (approximately 3.5 times that of a .30-06.) This is well beyond the limits of most shooters.
The .300 Remington Ultra Magnum, also known as the .300 Ultra Mag' or .300 RUM is a 7.62mm (.308in.) caliber rifle cartridge, 7.62×72mm, or .30 caliber rifle cartridge introduced by Remington Arms in 1999. The .300 Remington Ultra Magnum is one of the largest commercially available .30 caliber magnums currently being produced. It is a beltless, rebated rim cartridge, capable of handling all large North American game, as well as long-range shooting. Among commercially produced .30-caliber rifle chamberings, the .300 Remington Ultra Magnum is second to the .30-378 Weatherby Magnum in cartridge-case capacity.
Origin & History
In the early 1980s Aubrey White and Noburo Uno of North American Shooting Systems (NASS) based in British Columbia Canada began experimenting with the full length .404 Jeffery by reducing the taper and necking it down to various calibers such as 7mm, .308, 311, 338, 9.3mm and .375. These cartridges were known variously as the Canadian Magnum or the Imperial Magnums. Rifles were built on Remington Model 700 Long Actions and used McMillan stocks. Cartridges were fire formed from .404 Jeffery cases with the rim turned down, taper reduced and featured sharp shoulders.
It is a beltless, rebated rim cartridge based on the .300 Remington Ultra Magnum case shortened .090" and necked-up to accept a 0.338-inch (.338 caliber) bullet. The .338 Remington Ultra Magnum has a similar case capacity as the .338 Lapua Magnum and somewhat lower than that of the .338-378 Weatherby Magnum. It is one of the most powerful .338-caliber rounds in production.
Because this cartridge already operates at very high pressures (65,000 PSI), handloaders cannot realize significant velocity improvements over factory ammunition as many handloaders have done over the years with more conventional, lower pressure rounds. However, they can still tune their own loads for best precision in their specific rifles, as with any other cartridge.
Remington Ultra Magnum, or RUM, refers to a "family" of cartridges developed in 1999 and the early 2000s by Remington Arms. All of the RUM cartridges are based on the .404 Jeffery non-belted magnum cartridge. There is a long-case line, as well as a shortened version designed to fit a short rifle action (such as a .308 Winchester). The long case is very large and provides performance that exceeds existing commercial magnums, such as the .300 Winchester Magnum and .300 Weatherby Magnum.
The short design is the same idea as used in the Winchester Short Magnum cartridges. The shorter cartridges are known as Remington Short Action Ultra Magnum, RSAUM, RSUM, or SAUM.
The RUM family of cartridges are Delta L problem cartridges, meaning they can present unexpected chambering and/or feeding problems. The Delta L problem article explains this problem in more detail.
Influences
7.21 Lazzeroni
The RUM family is based on work done creating short magnums by John Lazzeroni, similar to the Winchester Short Magnum line. Lazzeroni's short magnums (7.21 Lazzeroni Tomahawk) were designed to operate in a short-action rifle, instead of requiring a long action. The U.S. Repeating Arms Company was the first major manufacturer to commercialize Lazzeroni's concept, followed shortly thereafter by Remington with their "Short Action Ultra Mag" line.
Speed shooting REm 375 Rum
Never do this if there is anyone even remotely behind you.
published: 29 Mar 2008
Scoped by the 375 RUM
He slightly underestimated the recoil of the 375 Remington Ultra Magnum.
published: 16 Apr 2014
375 Ultra Mag
375 Ultra Mag
published: 06 Oct 2008
Ultimate Guide To 9.3mm & 375 Cal Cartridges | 9.3x62, 375 H&H, 375 Ruger, 375 RUM, 375 Wby & More!
This video is your ultimate guide to the most popular 9.3mm and .375 caliber cartridges where I discuss the most popular 9.3mm and 375 caliber CIP and/or SAAMI certified cartridges and discuss their history, legacy, their strengths and weaknesses, and their recommended uses in detail. Specifically, I talk about the 9.3x72R, 9.3x57mm, 9.3x62mm, 9.3x74R, 9.3x64mm Brenneke, 370 Sako (9.3x66mm), 38-55 Winchester, 375 Winchester, 376 Steyr, 375 Holland & Holland Magnum (375 H&H), 375 Flanged, 375 Ruger, 375 Weatherby Magnum, 375 Ackley Improved, 375 Remington Ultra Magnum (375 RUM), 378 Weatherby Magnum, 375 Swiss P (9.5x70mm)& 375 CheyTac.
Most of those cartridges are very popular for hunting Africa, but as you’ll learn here shortly, that’s not the case with all of them. Indeed, a couple are ...
published: 12 Feb 2024
375 Remington Ultra Mag www.nyatiinc.com
375 Remington Ultra Mag Intermediate Load
published: 14 Oct 2011
338 Win Mag vs 375 H&H: Surprising Results On Steel
In today's video, we will be comparing the performance of the 338 Winchester Magnum and the 375 H&H Magnum on mild steel. These are two absolute power houses, so I hope you enjoy. Testing was setup at 50 yards using A529 gr 55 mild steel along with steel sled v3. Thanks for watching!
Steel Sled 4.0 is coming.
Testing: 2:32
*These tests are meant for entertainment and educational purposes only. Shooting steel can be dangerous, so do not try any of these tests at home!
Local Elevator by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license.
https://creativecommons.org/licenses/by/4.0/
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300012
Artist: http://incompetech.com/
#midwayusa
This video is your ultimate guide to the most popular 9.3mm and .375 caliber cartridges where I discuss the most popular 9.3mm and 375 caliber CIP and/or SAAMI ...
This video is your ultimate guide to the most popular 9.3mm and .375 caliber cartridges where I discuss the most popular 9.3mm and 375 caliber CIP and/or SAAMI certified cartridges and discuss their history, legacy, their strengths and weaknesses, and their recommended uses in detail. Specifically, I talk about the 9.3x72R, 9.3x57mm, 9.3x62mm, 9.3x74R, 9.3x64mm Brenneke, 370 Sako (9.3x66mm), 38-55 Winchester, 375 Winchester, 376 Steyr, 375 Holland & Holland Magnum (375 H&H), 375 Flanged, 375 Ruger, 375 Weatherby Magnum, 375 Ackley Improved, 375 Remington Ultra Magnum (375 RUM), 378 Weatherby Magnum, 375 Swiss P (9.5x70mm)& 375 CheyTac.
Most of those cartridges are very popular for hunting Africa, but as you’ll learn here shortly, that’s not the case with all of them. Indeed, a couple are uniquely American or European hunting cartridges and a couple of others aren’t even hunting cartridges at all!
To learn more about popular calibers like the 375 H&H, visit: https://huntingguns101.com/optin1615146914565?utm_source=YouTube&utm_medium=referral&utm_campaign=HG101&utm_term=YT&utm_content=93and375
______________________________________________
HUNTING AND SHOOTING GEAR I LIKE AND USE
Hearing Protection: https://thebiggamehuntingblog.com/earbuds
My favorite scopes (blog article): https://thebiggamehuntingblog.com/best-rifle-scopes-for-hunting/
My favorite budget hunting rifles (blog article): https://thebiggamehuntingblog.com/best-hunting-rifles-under-500/
My favorite budget hunting rifle slings (blog article): https://thebiggamehuntingblog.com/best-hunting-rifle-slings/
The above links, or the pages referenced, contain affiliate links. Commissions earned.
______________________________________________
To learn more about the 9.3x62mm Mauser, 375 H&H Magnum, or 375 Ruger, visit:
https://thebiggamehuntingblog.com/the-93x62mm-mauser-html/
https://thebiggamehuntingblog.com/is-the-375-hh-magnum-the-most-versatile-big-game-hunting-cartridge-of-all-time/
https://thebiggamehuntingblog.com/375-ruger/
-----------------------------------------------------------------------------------------------
Follow BGHB:
https://thebiggamehuntingblog.com/
Facebook: https://www.facebook.com/TheBigGameHuntingBlog
Instagram: https://www.instagram.com/thebiggamehunter_/
Twitter: https://twitter.com/TheBigGameHunt
-----------------------------------------------------------------------------------------------
0:00 Intro
1:46 9.3x72R
9:20 9.3x57mm
11:15 9.3x62mm
19:17 9.3x74R
22:25 9.3x64mm Brenneke
26:38 370 Sako (9.3x66mm)
28:44 38-55 Winchester
30:50 375 Winchester
33:29 376 Steyr
40:02 375 Holland & Holland Magnum (375 H&H)
50:28 375 Flanged
55:30 375 Ruger
1:04:57 375 Weatherby Magnum & 375 Ackley Improved
1:12:33 375 Remington Ultra Magnum (375 RUM)
1:21:20 378 Weatherby Magnum
1:26:29 375 Swiss P (9.5x70mm)
1:28:11 375 CheyTac
9.3x72R
9.3x57mm Mauser
9.3x62mm Mauser
9.3x74R
9.3x64mm Brenneke
370 Sako (9.3x66mm)
38-55 Winchester
38-55 Ballard
375 Winchester
376 Steyr
375 Holland & Holland Magnum (375 H&H Magnum)
375 Flanged
375 Ruger
375 Weatherby Magnum
375 Ackley Improved
375 Remington Ultra Magnum (375 RUM)
378 Weatherby Magnum
375 Swiss P (9.5x70mm)
375 CheyTac
This video is your ultimate guide to the most popular 9.3mm and .375 caliber cartridges where I discuss the most popular 9.3mm and 375 caliber CIP and/or SAAMI certified cartridges and discuss their history, legacy, their strengths and weaknesses, and their recommended uses in detail. Specifically, I talk about the 9.3x72R, 9.3x57mm, 9.3x62mm, 9.3x74R, 9.3x64mm Brenneke, 370 Sako (9.3x66mm), 38-55 Winchester, 375 Winchester, 376 Steyr, 375 Holland & Holland Magnum (375 H&H), 375 Flanged, 375 Ruger, 375 Weatherby Magnum, 375 Ackley Improved, 375 Remington Ultra Magnum (375 RUM), 378 Weatherby Magnum, 375 Swiss P (9.5x70mm)& 375 CheyTac.
Most of those cartridges are very popular for hunting Africa, but as you’ll learn here shortly, that’s not the case with all of them. Indeed, a couple are uniquely American or European hunting cartridges and a couple of others aren’t even hunting cartridges at all!
To learn more about popular calibers like the 375 H&H, visit: https://huntingguns101.com/optin1615146914565?utm_source=YouTube&utm_medium=referral&utm_campaign=HG101&utm_term=YT&utm_content=93and375
______________________________________________
HUNTING AND SHOOTING GEAR I LIKE AND USE
Hearing Protection: https://thebiggamehuntingblog.com/earbuds
My favorite scopes (blog article): https://thebiggamehuntingblog.com/best-rifle-scopes-for-hunting/
My favorite budget hunting rifles (blog article): https://thebiggamehuntingblog.com/best-hunting-rifles-under-500/
My favorite budget hunting rifle slings (blog article): https://thebiggamehuntingblog.com/best-hunting-rifle-slings/
The above links, or the pages referenced, contain affiliate links. Commissions earned.
______________________________________________
To learn more about the 9.3x62mm Mauser, 375 H&H Magnum, or 375 Ruger, visit:
https://thebiggamehuntingblog.com/the-93x62mm-mauser-html/
https://thebiggamehuntingblog.com/is-the-375-hh-magnum-the-most-versatile-big-game-hunting-cartridge-of-all-time/
https://thebiggamehuntingblog.com/375-ruger/
-----------------------------------------------------------------------------------------------
Follow BGHB:
https://thebiggamehuntingblog.com/
Facebook: https://www.facebook.com/TheBigGameHuntingBlog
Instagram: https://www.instagram.com/thebiggamehunter_/
Twitter: https://twitter.com/TheBigGameHunt
-----------------------------------------------------------------------------------------------
0:00 Intro
1:46 9.3x72R
9:20 9.3x57mm
11:15 9.3x62mm
19:17 9.3x74R
22:25 9.3x64mm Brenneke
26:38 370 Sako (9.3x66mm)
28:44 38-55 Winchester
30:50 375 Winchester
33:29 376 Steyr
40:02 375 Holland & Holland Magnum (375 H&H)
50:28 375 Flanged
55:30 375 Ruger
1:04:57 375 Weatherby Magnum & 375 Ackley Improved
1:12:33 375 Remington Ultra Magnum (375 RUM)
1:21:20 378 Weatherby Magnum
1:26:29 375 Swiss P (9.5x70mm)
1:28:11 375 CheyTac
9.3x72R
9.3x57mm Mauser
9.3x62mm Mauser
9.3x74R
9.3x64mm Brenneke
370 Sako (9.3x66mm)
38-55 Winchester
38-55 Ballard
375 Winchester
376 Steyr
375 Holland & Holland Magnum (375 H&H Magnum)
375 Flanged
375 Ruger
375 Weatherby Magnum
375 Ackley Improved
375 Remington Ultra Magnum (375 RUM)
378 Weatherby Magnum
375 Swiss P (9.5x70mm)
375 CheyTac
In today's video, we will be comparing the performance of the 338 Winchester Magnum and the 375 H&H Magnum on mild steel. These are two absolute power houses, s...
In today's video, we will be comparing the performance of the 338 Winchester Magnum and the 375 H&H Magnum on mild steel. These are two absolute power houses, so I hope you enjoy. Testing was setup at 50 yards using A529 gr 55 mild steel along with steel sled v3. Thanks for watching!
Steel Sled 4.0 is coming.
Testing: 2:32
*These tests are meant for entertainment and educational purposes only. Shooting steel can be dangerous, so do not try any of these tests at home!
Local Elevator by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license.
https://creativecommons.org/licenses/by/4.0/
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300012
Artist: http://incompetech.com/
#midwayusa
In today's video, we will be comparing the performance of the 338 Winchester Magnum and the 375 H&H Magnum on mild steel. These are two absolute power houses, so I hope you enjoy. Testing was setup at 50 yards using A529 gr 55 mild steel along with steel sled v3. Thanks for watching!
Steel Sled 4.0 is coming.
Testing: 2:32
*These tests are meant for entertainment and educational purposes only. Shooting steel can be dangerous, so do not try any of these tests at home!
Local Elevator by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license.
https://creativecommons.org/licenses/by/4.0/
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300012
Artist: http://incompetech.com/
#midwayusa
This video is your ultimate guide to the most popular 9.3mm and .375 caliber cartridges where I discuss the most popular 9.3mm and 375 caliber CIP and/or SAAMI certified cartridges and discuss their history, legacy, their strengths and weaknesses, and their recommended uses in detail. Specifically, I talk about the 9.3x72R, 9.3x57mm, 9.3x62mm, 9.3x74R, 9.3x64mm Brenneke, 370 Sako (9.3x66mm), 38-55 Winchester, 375 Winchester, 376 Steyr, 375 Holland & Holland Magnum (375 H&H), 375 Flanged, 375 Ruger, 375 Weatherby Magnum, 375 Ackley Improved, 375 Remington Ultra Magnum (375 RUM), 378 Weatherby Magnum, 375 Swiss P (9.5x70mm)& 375 CheyTac.
Most of those cartridges are very popular for hunting Africa, but as you’ll learn here shortly, that’s not the case with all of them. Indeed, a couple are uniquely American or European hunting cartridges and a couple of others aren’t even hunting cartridges at all!
To learn more about popular calibers like the 375 H&H, visit: https://huntingguns101.com/optin1615146914565?utm_source=YouTube&utm_medium=referral&utm_campaign=HG101&utm_term=YT&utm_content=93and375
______________________________________________
HUNTING AND SHOOTING GEAR I LIKE AND USE
Hearing Protection: https://thebiggamehuntingblog.com/earbuds
My favorite scopes (blog article): https://thebiggamehuntingblog.com/best-rifle-scopes-for-hunting/
My favorite budget hunting rifles (blog article): https://thebiggamehuntingblog.com/best-hunting-rifles-under-500/
My favorite budget hunting rifle slings (blog article): https://thebiggamehuntingblog.com/best-hunting-rifle-slings/
The above links, or the pages referenced, contain affiliate links. Commissions earned.
______________________________________________
To learn more about the 9.3x62mm Mauser, 375 H&H Magnum, or 375 Ruger, visit:
https://thebiggamehuntingblog.com/the-93x62mm-mauser-html/
https://thebiggamehuntingblog.com/is-the-375-hh-magnum-the-most-versatile-big-game-hunting-cartridge-of-all-time/
https://thebiggamehuntingblog.com/375-ruger/
-----------------------------------------------------------------------------------------------
Follow BGHB:
https://thebiggamehuntingblog.com/
Facebook: https://www.facebook.com/TheBigGameHuntingBlog
Instagram: https://www.instagram.com/thebiggamehunter_/
Twitter: https://twitter.com/TheBigGameHunt
-----------------------------------------------------------------------------------------------
0:00 Intro
1:46 9.3x72R
9:20 9.3x57mm
11:15 9.3x62mm
19:17 9.3x74R
22:25 9.3x64mm Brenneke
26:38 370 Sako (9.3x66mm)
28:44 38-55 Winchester
30:50 375 Winchester
33:29 376 Steyr
40:02 375 Holland & Holland Magnum (375 H&H)
50:28 375 Flanged
55:30 375 Ruger
1:04:57 375 Weatherby Magnum & 375 Ackley Improved
1:12:33 375 Remington Ultra Magnum (375 RUM)
1:21:20 378 Weatherby Magnum
1:26:29 375 Swiss P (9.5x70mm)
1:28:11 375 CheyTac
9.3x72R
9.3x57mm Mauser
9.3x62mm Mauser
9.3x74R
9.3x64mm Brenneke
370 Sako (9.3x66mm)
38-55 Winchester
38-55 Ballard
375 Winchester
376 Steyr
375 Holland & Holland Magnum (375 H&H Magnum)
375 Flanged
375 Ruger
375 Weatherby Magnum
375 Ackley Improved
375 Remington Ultra Magnum (375 RUM)
378 Weatherby Magnum
375 Swiss P (9.5x70mm)
375 CheyTac
In today's video, we will be comparing the performance of the 338 Winchester Magnum and the 375 H&H Magnum on mild steel. These are two absolute power houses, so I hope you enjoy. Testing was setup at 50 yards using A529 gr 55 mild steel along with steel sled v3. Thanks for watching!
Steel Sled 4.0 is coming.
Testing: 2:32
*These tests are meant for entertainment and educational purposes only. Shooting steel can be dangerous, so do not try any of these tests at home!
Local Elevator by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license.
https://creativecommons.org/licenses/by/4.0/
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300012
Artist: http://incompetech.com/
#midwayusa
The .375 Remington Ultra Magnum, also known as the .375 RUM is a .375 riflecartridge introduced by Remington Arms in 2000. The cartridge is intended for large and dangerous game.
It is a beltless, rebated rim cartridge created by necking up the .300 Remington Ultra Magnum case to .375 caliber with no other changes. Factory loadings are less powerful than handloads for the cartridge. Remington factory loads push a 300 grain (19 g) bullet at 2760ft/s (840m/s), producing 5070ft·lbf (6.88 kJ) of energy. A handloader can increase the muzzle velocity of a 220gr bullet to 3321ft/s (900m/s), and develop 5800ft·lbf (7.9 kJ).
General information
The intended use of this cartridge includes hunting large, thick-skinned game. It is powerful enough to kill any land animal and, with its high velocity, can do so at fairly long ranges. One should note that such performance comes at the price of a heavy recoil: in a sporting-weight rifle of ~8lb (3.6kg), this cartridge can produce a fierce 80ft·lbf (108 J) of recoil (approximately 3.5 times that of a .30-06.) This is well beyond the limits of most shooters.