7 lrm Thoughts

Sorry, you guys that love the belted cases have it all wrong. Charles Newton created the .30 Newton in like 1913 or something like that, way before the .300 WM or the 7mm RM, even before the .300 H&H. His design was the original .308 caliber magnum, which is very similar to this new offering from Hornady. Whoever it was that decided to use a belted case for the modern magnum cartridge messed it up, Hornady is finally setting the world straight. :)
 
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When Ruger first announced the .375 Ruger there was a good deal of discussion about the case and what a great parent case it would make for 6.5, 7mm, .30, and .338 offshoots in the future.

Much of that discussion was held right here and it has certainly proven to be a great case to work off of over the last few years.

Much like the original .300wm case it is going to be the basis for many more wildcats and standardized factory rounds for decades to come.

As much as I like my current string of .300wm's and .300 Rum's as well as my 6.5's I could easily see changing over when the time comes to replace barrels to using the variants using the .375R case if for no other reason than to simplify my reloading. We're guaranteed to have a steady supply of quality brass long into the future for the .375R which makes it very appealing to me for the future.
 
375 ruger and all its variants and wildcats are not rebated rim. Case head is .532 as is base diameter. Forming 7lrm brass will still require custom forning dies since the shoulder position is further forward on the 300 case. Gunworks gave the 7lrm a very long neck, the new 300 doesn't share that, plus it's a longer overall case.
 
gregsjt said:
Sorry, you guys that love the belted cases have it all wrong. Charles Newton created the .30 Newton in like 1913 or something like that, way before the .300 WM or the 7mm RM, even before the .300 H&H. His design was the original .308 caliber magnum, which is very similar to this new offering from Hornady. Whoever it was that decided to use a belted case for the modern magnum cartridge messed it up, Hornady is finally setting the world straight. :)
Click to expand...
ACTUALLY... You're incorrect. The .375 H&H came out in 1912, and is THE first belted magnum cartridge. ;)

.375 Belted H&H Magnum

The famous .375 Belted H&H Magnum (.375 H&H Mag. to Americans) was the first belted magnum cartridge, but not the first belted cartridge. The latter honor goes to the .400/.375 Belted Nitro Express, introduced in 1905 by Holland & Holland. The rimless, belted case design was intended to provide a positive edge for headspacing, like a rim, and yet still feed easily from the box magazines of repeating rifles. It was, of course, a very successful idea.

Holland & Holland refined and enlarged the belted case and in 1912 introduced the seminal .375 H&H Magnum, which spawned a rash of popular belted magnum cases. The .375 Magnum case has a .532" rim diameter and this has become the standard rim diameter for standard (.30-06 length) and long (.375 H&H length) magnum cases.

Strangely, despite their diversity and number, few of the long magnum cartridges have been very successful in the marketplace. Today only the original .375 H&H and the .300 Weatherby, probably the best seller among the full length magnums, enjoy much popularity. Among the small bore calibers, the .275 is dead and the .244 H&H, .300 H&H and 8mm Rem. Magnums appear to be on the way out. The 7mm STW had a modest run of popularity that appears to have waned, although it is loaded by all of the major U.S. ammo manufacturers. Probably its propensity to burn-out barrels has not helped its reputation.

The medium and big bore magnums have their place as specialty cartridges and it is here that the big case magnums make the most sense. Unfortunately, few game animals require such cartridges and even fewer shooters can tolerate their outsized recoil. Those factors definitely limit their sales appeal. Factory loaded cartridges based on the full length .375 H&H case include:

  • .244 H&H Magnum
  • .275 H&H Magnum*
  • 7mm STW
  • .300 H&H Magnum
  • .300 Weatherby Magnum
  • 8mm Remington Magnum
  • .340 Weatherby Magnum
  • .375 H&H Magnum
  • .375 Weatherby Magnum
  • .400 H&H Magnum
  • .416 Remington Magnum
  • .458 Lott
  • .465 H&H Magnum
The widespread adoption of the .375 H&H case with its big .532" rim diameter provided a big increase in powder capacity compared to 8x57 and .30-06 size cases, but the 3.600" COL of the .375 H&H cartridge required a special long action that some manufacturers did (and do) not build.

Considerable demand developed for standard (.30-06) length cartridges based on a shortened (and blown-out) .375 H&H case. Many of these cartridges have achieved factory loaded status, and the 7mm Rem. Mag. became the best selling of all magnum cartridges, followed by the .300 Win. Mag. and the .338 Win. Mag. These three are in the top 10 on cartridge sales lists, the only magnum cartridges ever to attain that status. The 7mm Rem. Mag. made our short list of all-around rifle cartridges (see the article "All-Around Rifle Cartridges" on the Rifle Information Page) and the .338 Win. Mag. is the premier Western elk and Alaskan CXP3 game cartridge.

Most of the standard length magnums are reasonably healthy. Only the 7x61 S&H Super is obsolete and the critical list is limited to the Norma pair. Here are the standard length belted magnum cartridges derived from a shortened .375 H&H case:

  • .257 Weatherby Magnum
  • .264 Winchester Magnum
  • .270 Weatherby Magnum
  • 7x61 Sharpe & Hart Super*
  • 7mm Remington Magnum
  • 7mm Weatherby Magnum
  • .308 Norma Magnum
  • .300 Winchester Magnum
  • .338 Winchester Magnum
  • .358 Norma Magnum
  • .458 Winchester Magnum
In the mid-1960's Remington went the rest of the boys one step farther by introducing a pair of true short action (.308 length) magnum cartridges based on an even shorter version of the .375 H&H case. These 6.5mm and .350 caliber cartridges did not catch on, although the .350 Rem. Mag. became a cult classic in Alaska as a "guide rifle" cartridge for protection against the great bears as well as a Guns and Shooting Online favorite. (See the article "Guns and Shooting Online Rifle Cartridges" on the Rifle Information Page).

The Remington short magnums seemed to be obsolete when the less well balanced WSM and SAUM cartridges hit the market in 2000 with much media fanfare. The hype surrounding the squat WSM cartridges, which were not based on the .375 belted case, revived interest in Remington's original short action magnums, giving them a new lease on life, so here they are:

  • 6.5mm Remington Magnum
  • .350 Remington Magnum
Both of Remington's original short magnums are back in production as I write these words and Remington and Ruger are offering new factory built rifles in .350 Rem. Mag. caliber.
Click to expand...

https://www.chuckhawks.com/great_cartridge_families.htm
 
MudRunner2005 said:
ACTUALLY... You're incorrect. The .375 H&H came out in 1912, and is THE first belted magnum cartridge. ;)



https://www.chuckhawks.com/great_cartridge_families.htm
Click to expand...

I said the first .308 caliber magnum, not the first "belted magnum". I could still be wrong, but I do know that Newton beat the .300 H&H by 12 or 13 years. Its too bad his design didn't catch on, the belted cases on the H&H magnums were probably needed, but for all the other derivatives (Weatherbys, Win Mag, ect.) the belt served more as a marketing ploy than anything else.
 
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