17-04-2008, 01:22 AM
17-04-2008, 01:39 AM
Fandt lidt interessant læsning men ingen angivelse af krudttype der er brugt.
Remington's Short-Action Ultra Mags
Initially Remington will be offering two loads for the 7mm SA Ultra, a 140-gr. Core Lokt Ultra and a 160-gr. Nosler Partition. At the time of testing only the 140-gr. load was available for the author to shoot.
Not only was the mid-year introduction of these new cartridges and bullet highly unusual for Remington, so too was the fact that I actually had a test rifle in 7mm SA Ultra in my hands within a week after returning home from Madison, and the ammo just a few days after that! I can't tell you how rare that is!
The rifle sent me was one of several that had been available for shooting at the press conference the week before. It all could not have worked out better for me because this all happened just three weeks before I was to leave for a plains game hunt in the Kimberly region of South Africa.
Since neither Browning nor U.S. Repeating Arms anticipated shipping A-Bolts or Model 70s in .300 WSM before my scheduled departure, I had long since committed to take an H-S Precision Pro-Series 2000 rifle on this hunt. H-S had begun chambering for the .300 WSM shortly after it was officially announced at the last SHOT Show, so I knew I'd have one of them in time. I couldn't pass up this opportunity, however, so I plan to also bring the SA Ultra Mag with me as well, along with the new 140-gr. Core Lokt Ultra load to field test.
Only two Remington rifles are being chambered for the SAUMs this year, and both are Model Sevens. Officially designated as the Model Seven Magnum, the one I've got is the SS version with an all-stainless, sightless barreled action in a black, injection-molded stock. The other option is the LS, which sports a blued barreled action with sights, set into a brown laminated stock. Nominal weight for both guns is said to be 71#8260;8 lbs. My rifle came with a Leupold Compact 3-9x scope already mounted and weighed 81#8260;4 lbs. field ready.
Oddly enough, both models come with a 22-inch barrel as standard, so for this year anyway, no production Remington will be capable of extracting the advertised muzzle velocity in either caliber. To keep the rifle at a sensible weight for what are essentially 7mm and .300 magnum rifles, the barrel measures .700 at the muzzle, which is quite stout by pseudo-carbine standards.
Those wishing for a 24-inch barrel can either order the Model Seven AWR through the Custom Shop, or wait 'til next year when Remington will add both chamberings to several models in the 700 line. The AWR is distinguished by its Aramid fiber-reinforced fiberglass stock and Teflon-coated stainless barreled action. All three models feature three-round magazines with hinged floor plate.
The MSRP on the Model Seven Magnum SS is $719 in either caliber; for LS it's $673. The AWR out of the Custom Shop is $1,257.
As this is written I have but three days before I leave for Africa and I've had precious little time to spend with the gun. Nevertheless, I have managed three short range sessions with it using the limited amount of ammo sent me--less than five boxes, in fact, and I'm saving two of them for the hunt. I was promised loading dies would be shipped with the gun, but alas, that hasn't happened. It's no biggie, though, 'cause I want to use the new Core Lokt Ultra bullets, so I'm limited to using factory ammo in any case.
So far, only data for the 160-gr. Nosler Partition load is given. I, however, have received only the 140-gr. Core Lokt Ultra loads for which velocity data has yet to be published. I presume, however, they will be claiming to at least match the 140 gr. 7mm Rem. Mag loading of 3,175 fps. Indeed, the 10-shot string of factory ammo I put through the test gun averaged 3,135 fps through its 22-inch barrel.
Compared to its big brother, the new 7mm SA version at left achieves 3,175 fps with a 140-gr. bullet atop a charge of 60 grs. of powder. The huge Ultra Mag at right requires 50 percent more powder to achieve a bit less than an eight percent gain in velocity.
Considering a certain velocity loss of 50-60 fps for the two-inch shorter barrel, the loads I'll be using in Africa actually exceed 7 Mag performance. I hasten to add, however, that this is pre-production ammo I'm using and it's a little on the warm side. Bolt lift is a bit stiff, and there's a slight flow of brass into the ejector hole that's slightly burnished by bolt rotation. I'm guessing production ammo will be further refined to produce less pressure at or near the targeted velocities.
Remington's Ammunition Products Manager, John Chisnall, tells me that thus far a ball propellant similar to W-760 has worked best in the SAUM's. In the 140-gr. Core Lokt Ultra load I've got, there's a 60-gr. charge. Do not interpret this to be loading data; I'm only reporting that there is a charge of 60 grs. of an unknown ball propellant in this particular factory load.
It's always interesting to compare the efficiency of these new short magnums like Lazzeronis, the Winchester, and now the two Remingtons, with larger-cased equivalent calibers. Take the equally new, magnum-length 7mm Ultra Mag introduced just a few months before the SA version, for example.
The former requires a propellant charge of 90 grs. to push a bullet of 140 grs. to 3,425 fps. That means, to achieve a little over a seven percent increase in velocity over the SA version requires 50 percent more powder, to say nothing of double the recoil, a barrel life measured in hundreds rather than thousands of rounds, and the extra length and weight of a magnum action.
With Remington having thrown its hat into the short action magnum arena, it can definitely be said that this new direction is not just a flash in the pan; it's going to change forever how future generations of hunters and shooters perceive sporting cartridges. And it won't stop here. Look for Winchester to introduce a .338, a 7mm and/or a .270 version of their WSM, and Remington to also add a .338, as well as something smaller than 7mm, perhaps a .25 or 6.5.
Yep. It's all going to be verrr-ry interesting!
![[Image: modibuk07.jpg]](http://i148.photobucket.com/albums/s32/vrangbaek/modibuk07.jpg)
+GONE2HUNT+
Remington's Short-Action Ultra Mags
Initially Remington will be offering two loads for the 7mm SA Ultra, a 140-gr. Core Lokt Ultra and a 160-gr. Nosler Partition. At the time of testing only the 140-gr. load was available for the author to shoot.
Not only was the mid-year introduction of these new cartridges and bullet highly unusual for Remington, so too was the fact that I actually had a test rifle in 7mm SA Ultra in my hands within a week after returning home from Madison, and the ammo just a few days after that! I can't tell you how rare that is!
The rifle sent me was one of several that had been available for shooting at the press conference the week before. It all could not have worked out better for me because this all happened just three weeks before I was to leave for a plains game hunt in the Kimberly region of South Africa.
Since neither Browning nor U.S. Repeating Arms anticipated shipping A-Bolts or Model 70s in .300 WSM before my scheduled departure, I had long since committed to take an H-S Precision Pro-Series 2000 rifle on this hunt. H-S had begun chambering for the .300 WSM shortly after it was officially announced at the last SHOT Show, so I knew I'd have one of them in time. I couldn't pass up this opportunity, however, so I plan to also bring the SA Ultra Mag with me as well, along with the new 140-gr. Core Lokt Ultra load to field test.
Only two Remington rifles are being chambered for the SAUMs this year, and both are Model Sevens. Officially designated as the Model Seven Magnum, the one I've got is the SS version with an all-stainless, sightless barreled action in a black, injection-molded stock. The other option is the LS, which sports a blued barreled action with sights, set into a brown laminated stock. Nominal weight for both guns is said to be 71#8260;8 lbs. My rifle came with a Leupold Compact 3-9x scope already mounted and weighed 81#8260;4 lbs. field ready.
Oddly enough, both models come with a 22-inch barrel as standard, so for this year anyway, no production Remington will be capable of extracting the advertised muzzle velocity in either caliber. To keep the rifle at a sensible weight for what are essentially 7mm and .300 magnum rifles, the barrel measures .700 at the muzzle, which is quite stout by pseudo-carbine standards.
Those wishing for a 24-inch barrel can either order the Model Seven AWR through the Custom Shop, or wait 'til next year when Remington will add both chamberings to several models in the 700 line. The AWR is distinguished by its Aramid fiber-reinforced fiberglass stock and Teflon-coated stainless barreled action. All three models feature three-round magazines with hinged floor plate.
The MSRP on the Model Seven Magnum SS is $719 in either caliber; for LS it's $673. The AWR out of the Custom Shop is $1,257.
As this is written I have but three days before I leave for Africa and I've had precious little time to spend with the gun. Nevertheless, I have managed three short range sessions with it using the limited amount of ammo sent me--less than five boxes, in fact, and I'm saving two of them for the hunt. I was promised loading dies would be shipped with the gun, but alas, that hasn't happened. It's no biggie, though, 'cause I want to use the new Core Lokt Ultra bullets, so I'm limited to using factory ammo in any case.
So far, only data for the 160-gr. Nosler Partition load is given. I, however, have received only the 140-gr. Core Lokt Ultra loads for which velocity data has yet to be published. I presume, however, they will be claiming to at least match the 140 gr. 7mm Rem. Mag loading of 3,175 fps. Indeed, the 10-shot string of factory ammo I put through the test gun averaged 3,135 fps through its 22-inch barrel.
Compared to its big brother, the new 7mm SA version at left achieves 3,175 fps with a 140-gr. bullet atop a charge of 60 grs. of powder. The huge Ultra Mag at right requires 50 percent more powder to achieve a bit less than an eight percent gain in velocity.
Considering a certain velocity loss of 50-60 fps for the two-inch shorter barrel, the loads I'll be using in Africa actually exceed 7 Mag performance. I hasten to add, however, that this is pre-production ammo I'm using and it's a little on the warm side. Bolt lift is a bit stiff, and there's a slight flow of brass into the ejector hole that's slightly burnished by bolt rotation. I'm guessing production ammo will be further refined to produce less pressure at or near the targeted velocities.
Remington's Ammunition Products Manager, John Chisnall, tells me that thus far a ball propellant similar to W-760 has worked best in the SAUM's. In the 140-gr. Core Lokt Ultra load I've got, there's a 60-gr. charge. Do not interpret this to be loading data; I'm only reporting that there is a charge of 60 grs. of an unknown ball propellant in this particular factory load.
It's always interesting to compare the efficiency of these new short magnums like Lazzeronis, the Winchester, and now the two Remingtons, with larger-cased equivalent calibers. Take the equally new, magnum-length 7mm Ultra Mag introduced just a few months before the SA version, for example.
The former requires a propellant charge of 90 grs. to push a bullet of 140 grs. to 3,425 fps. That means, to achieve a little over a seven percent increase in velocity over the SA version requires 50 percent more powder, to say nothing of double the recoil, a barrel life measured in hundreds rather than thousands of rounds, and the extra length and weight of a magnum action.
With Remington having thrown its hat into the short action magnum arena, it can definitely be said that this new direction is not just a flash in the pan; it's going to change forever how future generations of hunters and shooters perceive sporting cartridges. And it won't stop here. Look for Winchester to introduce a .338, a 7mm and/or a .270 version of their WSM, and Remington to also add a .338, as well as something smaller than 7mm, perhaps a .25 or 6.5.
Yep. It's all going to be verrr-ry interesting!
+GONE2HUNT+
17-04-2008, 10:52 AM