January 04, 2011
The 6.8 SPC is a round that easily outperforms the 5.56x45 and 7.62x39.
Although it developed the cartridge, Remington no longer chambers it, but several AR makers do, and Ruger has it in a Mini-14 and a Model 77 Hawkeye Compact.
Along about the time President George W. Bush declared war on foreign terrorists, the U.S. Army Special Operations Command initiated the Special Purpose Rifle-Variant program. Its mission was to come up with a modular assault rifle version of the M4 carbine capable of handling both the 5.56x45 and the 7.62x39 Russian cartridges. By switching bolts, barrels and magazines, it could quickly be changed from one to the other.
A few were built, and while the program was rather short-lived, it lasted long enough for Special Forces troops to witness first-hand the increased long-range lethality of a .30 caliber cartridge over one of .22 caliber. This held especially true when the bullet had to travel through any type of barrier before reaching its intended target.
Incidents of American soldiers being killed by Taliban fighters who had been shot several times with the .22 caliber M4 prompted the 5th Special Forces Group to design what was described as an Enhanced Rifle Cartridge, one capable of outperforming both the 5.56x45 and 7.62x39. Master Sgt. Steve Holland of the 5th Special Forces Group and Chris Murray of the U.S. Army Marksmanship Unit headed up the ERC project and were assisted by Chief Ballistic Technician Troy Lawton.
Several prototype cartridges were tested, one on the 6mm PPC case, but neither proved entirely compatible with the M4 platform. What they needed was a cartridge with a rim diameter larger than the 5.56 but smaller than the 7.62x39, and the answer came with an old-timer that began life in 1906.
Introduced along with cartridges on the same case but in .25 and .32 calibers for Remington's equally new Model 8 autoloading rifle, the .30 Remington Rimless pretty much duplicated the performance of the .30-30 Winchester. Its nominal rim diameter is .421 inch compared to .378 inch for the 5.56 and .447 inch of the 7.62x39. Shortening the .30 Remington case to a maximum of 1.686 inches resulted in a case compatible with the magazine of the M16 rifle and with a powder capacity about 32 percent greater than that of the 5.56x45.
When testing bullets in the new case, it became obvious that while those of 6.5mm were a bit more accurate than 7mm bullets, the latter did more damage to targets at 500 meters and beyond. Then its developers discovered that .270 bullets shot about as flat and with about as much accuracy as 6.5mm bullets and delivered about as much downrange punch as 7mm bullets. And since the bore diameter of a .270 barrel is usually around 6.8mm and the parent case was a Remington development, the name given to the new cartridge by its creators was 6.8mm Remington Special Purpose Cartridge.
With a velocity goal of at least 200 fps faster than the 7.62x39, they found what they were looking for in the Sierra 115-grain MatchKing and the Hornady 110-grain hollowpoint bullets. During extensive testing, velocities up to 2,650 fps were reached with those bullets, or about 350 fps faster than the standard 123-grain loading of 7.62x39.
Remington assumed further development of the 6.8mm SPC in 2002 and introduced it as a commercial cartridge in 2004. It presently offers four loadings: 115-grain standard hollowpoint; full metal jacket; Sierra MatchKing; and Remington Core-Lokt Ultra Bonded bullets--all at a muzzle velocity of 2,625 fps.
Hornady has two loadings: one with a 110-grain boattail hollowpoint, the other with the 110-grain V-MAX, both at 2,550 fps. Hornady's advertised velocity is for a 16-inch barrel, and both loads average around 2,700 fps in my 24-inch barrel.
While the ammunition guys at Remington considered the cartridge worthy of developing a deer bullet specifically for the 6.8mm SPC, it has been virtually ignored by the rifle side of the business. For a short time the Model 700 SPS was available in 6.8mm SPC, but Remington's current catalog shows no rifle presently chambered for it--not even the R-15, an AR platform.
Overall, the company is doing an excellent job of ignoring its little cartridge to death. All is not lost, however, since a number of AR-15 companies--including Barrett, Bushmaster and DPMS--offer the chambering.
It is also available in the all-weather version of the Ruger Mini-14 Ranch Rifle. I have no plan to add another rifle in this caliber to my battery but should I change my mind I will take a serious look at the Ruger Model 77 Hawkeye Compact. It's a very nice little rifle, and it weighs only six pounds.
My experience with the 6.8mm SPC on game is limited. Soon after its introduction I used a custom Remington Model 700 in that caliber to bump off a caribou, and I have since used a T/C Contender rifle with an SSK Industries 24-inch barrel to take several whitetail deer and a hog or two.
The only bullet I have tried on game--the Remington 115-grain Core-Lokt Ultra--expands quite well, penetrates deeply enough and retains just over 60 percent of its original weight. Even though the caribou ended up quite dead, I knew before heading to Quebec that there are many better caribou cartridges, and while it has proven to be deadly enough on deer, I have intentionally held my fire on any buck standing farther away than 250 yards.
|6.8mm Remington SPC Load Guide|
|Bullet||Bullet Weight (gr.)||Powder Type||Powder Charge (gr.) || Muzzle Velocity (fps)|
|Sierra HP|| 90 ||H335 || 33.0 || 3,017 |
|Hornady SP || 100 ||H4198 || 26.0 || 2,739 |
| Barnes TSX BT || 110 ||H322 || 29.0 || 2,744 |
| Hornady V-MAX|| 110 ||H335 || 30.0|| 2,721 |
|Sierra MatchKing ||115 ||H335 || 29.0 || 2,610 |
|Hornady SST* || 130 ||RL-10X ||25.0 || 2,502 |
| Sierra MatchKing* || 135 ||Benchmark || 28.5 || 2,489 |
| Hornady BTHP Match || 110 ||Hornady factory|| ||2,698 |
| Hornady V-Max|| 110 || Hornady factory || || 2,713 |
| Sierra MatchKing|| 115 || Remington factory || || 2,610 |
| Remington C-LUB|| 115 || Remington factory || || 2,587 |
|WARNING: The loads shown here are safe only in the guns for which they were developed. Neither the author nor InterMedia Outdoors, Inc. assumes any liability for accidents or injury resulting from the use or misuse of this data. Notes: *These bullets suitable only for bolt actions and single-shots. All powder charges should be reduced by 10 percent for starting loads. Velocities are averages of 10 rounds clocked at 12 feet from the muzzle of a SSK Industries 24-inch barrel. Remington cases and Federal 210M primers were used in all handloads. |
Reloading dies for the 6.8mm SPC are available from Hornady, Redding, RCBS and Lyman. Correct shell holder is the RCBS No. 19 or Redding No. 5, neither likely to be on most handloading benches since the only other cartridges it fits are the .25, .30 and .32 Remington.
I like the Federal 210M primer in this cartridge, and if I had to pick just one powder it would be H335. The Remington 115-grain Core-Lokt is the best deer bullet available in factory ammo, and the Barnes 110-grain TSX is probably the best choice for handloading.
Bolt actions and single-shots can handle heavier bullets, and those of relatively soft construction weighing 130 grains should not only expand satisfactorily on deer over the effective range of the cartridge, they are probably better choices than those weighing less.
When the Hornady 130-grain SST exits the muzzle of my 24-inch barrel at 2,500 fps, it is still moving along at about 2,100 fps at 300 yards, where it delivers 1,300 ft.-lbs. of energy. For shooting the smallest groups possible on paper, my picks of the bunch are the Sierra 115-grain MatchKing and Hornady 110-grain V-MAX.
As I write this, the U.S. Army has not officially adopted the 6.8mm SPC, and I'm thinking chances of it ever happening are quite slim. As a sporting cartridge, it offers excellent accuracy, extremely light recoil and enough punch for consistent kills on deer much farther away than most are shot. It may just be the best cartridge ever developed for a youngster's first deer rifle. Whether or not that's enough to keep it alive, only time will tell.