Can anyone relate their experience in designing
and building a rifle for a wilcat based on the
6.8 REM SPC case. I was thinking of 6.5 to get
a better selection of bullets than the 6.8 (.277)
bullets that are now available. I would be happy
with a simple neckdown modification but would like
to hear anyone else's ideas.

Just get this instead. All the development work is done. No wildcatting necessary.

A friend of mine necked down the 6.8 SPC case, initially to .264 and then to .243 cal. He believed the case volume of the 6.8 SPC would be better suited to a smaller caliber. I'm not sure what velocities he obtained, nor what other (dis-)advantages he encountered. I think his main point was to be able to use one of Mini-Mauser actions, with the same case head as the 6.8. Other than that, there are quite a few smaller cases around to wildcat on...

- mike

Check on http://www.reloadbench.com They have one on there.

You could neck down to .25 and up to .30 and .32. But I think those were already tried and called the 25, 30 & 32 Remington. Since the 6.8 is based on the 30 Rem case, do a search for wildcats on those three and you will see what ground has already been plowed.

We are building AR-15 match rifles in a 6mm version of the SPC. Changed the shoulder angle slightly, but that is about it. velocity in the 2650-2700 range with a 107, and 3200-3350 with a 70. Right now the problem is brass. The Rem stuff is very poor quality. Hornady seems to be better, and uses a small primer, but is hard to find right now. Silver State Armory is also making 6.8 brass and loaded ammo.

I think the brass has a lot of possibilities, particularly in small .223 sized actions and also in the AR-15. My next project as time allows is necking to .22. Should give close to .22 BR performance.

In my opinion the 6.5 Grendal as well as the SPC do not really have enough case capacity to be much fun in 6.5 or .270 bore diameters.

Interesting that if you take the 6.8 and neck it down to .22 you get a dead ringer for the .22 Lindahl Chucker or a rimless .219 Wasp with a slightly shorter neck.

John

quote:

Originally posted by Old Elk Hunter:
Can anyone relate their experience in designing
and building a rifle for a wilcat based on the
6.8 REM SPC case. I was thinking of 6.5 to get
a better selection of bullets than the 6.8 (.277)
bullets that are now available. I would be happy
with a simple neckdown modification but would like
to hear anyone else's ideas.

Are these not the same bullets as the 270 Winchest? If so, then there should be as good a bullet selection as any caliber up or down.

Yes, .270 bullets, but all designed for .270 win velocities. You just can't get them going fast enough with 30 gr case capacity.

John

Get ahold of a copy of Wildcat Cartridges by Dick Simmons. This book covers a lot of the old wildcat cartridges and their development. The 6.8 is nothing more than the old 30 Rem. case. Everything that has been done with the 30/30 has also been done with the 30 Rem case and the same results are obtained. Just a rimless 30/30.

quote:

Originally posted by gasgunner:
Yes, .270 bullets, but all designed for .270 win velocities. You just can't get them going fast enough with 30 gr case capacity.

John

You can fire a 110 gr bullet 2800 fps, plenty fast enough

quote:

Originally posted by MajorCaliber:

quote:

Originally posted by gasgunner:
Yes, .270 bullets, but all designed for .270 win velocities. You just can't get them going fast enough with 30 gr case capacity.

John

You can fire a 110 gr bullet 2800 fps, plenty fast enough

You're going to need a pretty long barrel and a pretty slow powder to do it.

Remington has not been able to do it in M16s, the rifle that the cartridge was designed for.

In addition to what HP Shooter said, a 110 gr .270 is going to be limited to short range due to the low BC and SD. As a 6mm we can get a 107 up to 2700 and it has a much higher bc and a heck of a lot less wind drift.

I sent one down to a customer in TX for some testing on deer, just got an e-mail from him. Two shots, two dead deer. Used 85 gr barnes triple shock. One at just over 200 yards took out the shoulder, heart, and broke a leg on the other side and exited.

John

The 6.8x43mm SPC was conceived by a U.S. Special Operations soldier in a quest to improve the terminal ballistics of the M4 Carbine. The U.S. Army Marksmanship Unit and others assisted the Spec Ops team heading the project. Although the main objective was increased lethality, the new cartridge would go far beyond that in terms of accuracy and performance.

After selecting the .30 Remington as the parent case--a decision that required only slight modification to the M16's bolt face--the case was shortened, given a new shoulder and blown out to maximum capacity for a new high-performance propellant. After testing a variety of bullets in 5.56mm, 6mm, 6.5mm, 7mm and 7.62mm, a bullet of 6.8mm was selected. This .270-caliber, 115-grain projectile has a ballistic coefficient of .350, offering optimum lethality and range.

Remington began to develop the 6.8x43 back in 2002 and is officially introducing it this year as the 6.8mm Rem SPC. As this is written, the cartridge has not been released to the public, but I can tell you that it provides one MOA accuracy out to more than 600 meters. It has a flight path almost identical to that of the .308 Winchester, less chamber pressure than the .223 and fits into the M16 magazine envelope. Tests in 10 percent ballistic gelatin show incapacitation as good or better than the .308.

After bore-sighting the CZ, I fired it from the bench. Loads using 110-grain Hornady V-Max bullets produced a three-shot, 100-yard group of .94 inch with an average of 1.18 inches. All groups centered about 1.5 inches high and left of point of aim and averaged 2,971 fps on my Competition Electronics ProChrono LE. Because of my limited supply of ammunition and the fact that there was a 20-mph gusting wind from the right, I called it good.

In addition to mule deer, I was prepared to use the 6.8mm Rem SPC on elk if the conditions were right. (Hornady's Wayne Holt summed it up by saying that the 110-grain V-Max should do at least as much damage as an arrow.)

6.8MMx47 REMINGTON SPC BALLISTICS
BULLET VELOCITY (fps) ENERGY (ft-lbs.)
Muzzle 100 yd. 200 yd. 300 yd. Muzzle 100 yd. 200 yd. 300 yd.
115-gr. FMJ 2,800 2,523 2,202 2,017 2,002 1,622 1,250 1,039
115-gr. BTHP 2,800 2,535 2,285 2,049 2,002 1,644 1,345 1,075
115-gr. MK 2,800 2,535 2,285 2,049 2,002 1,644 1,345 1,075
*24-inch Barrel


Opening day found my wife, Nancy, and I hunting north of Ridgway, Colorado, at about 8,000 feet where my friends had seen some big bucks the day before along with a herd of about 75 elk. We saw several nice bucks the first couple of days, but they were too far away, and the elk we spotted were even farther. I knew I would probably have to use my .300 Win. Mag. for elk, but I was determined to get a mule deer with the 6.8mm.

On the third day, I was glassing a field at midday when my partner, Jaysen Evans, saw a buck running. I turned and got the deer's east end in my scope as he headed west and disappeared into some scrub oak. I signaled Jaysen to go in wide and right while I stalked the buck. After I had gone about 25 yards, I saw it trotting away, but as mule deer often do, he stopped at about 75 yards and turned to look back at me through the scrub oak. I knelt and put my crosshairs on his ribs, but some brush was between us. I moved up until the reticle was clear, and I pressed the trigger.

As the shot cracked, the light recoil from the 6.8mm allowed me to see the buck do a backward summersault. He never got up. Jaysen and I estimated the deer at more than 200 pounds. What was left of the 110-grain .270 Hornady bullet had exited the opposite side of the rib cage, creating a large laceration. Both lungs had severe damage, and bullet and bone fragments had also damaged other organs. It was as clean a kill as I have ever made.

In addition to any role the 6.8mm Rem SPC will have as a military cartridge, I predict it will be extremely popular as a hunting cartridge for small- to medium-size game at ranges out to 300 yards or more as it is extremely flat-shooting. Remington is now producing the 6.8mm SPC in three loadings,

all with 115-grain bullets. The MatchKing Ballistic Tip Hollowpoint will deliver 2,800 fps and 2,002 ft-lbs of energy. It will also be offered in a standard BTHP loading and in an FMJ version, both with the same muzzle velocity out of a 24-inch barrel.

Remington is expected to introduce rifles for the 6.8mm SPC soon, but at press time no specifics were available. One rumor is that a heavy-barrel tactical rifle will be introduced and possibly a Model Seven. Other makers are waiting anxiously to chamber AR-type rifles and carbines, and several ammunition companies plan to load the new round. Look for more news soon in the pages of RifleShooter.

I'm going to get a 6.8 SPC upper for my RockRiver M4 lower

The 6.8 SPC will not have any role as a military cartridge. You read it here first.

quote:

Originally posted by HP Shooter:
The 6.8 SPC will not have any role as a military cartridge. You read it here first.

DUH? It's already in use in Afganistan, and Iraq!

quote:

Originally posted by MajorCaliber:

quote:

Originally posted by HP Shooter:
The 6.8 SPC will not have any role as a military cartridge. You read it here first.

DUH? It's already in use in Afganistan, and Iraq!

I hope you have hard evidence of that.

Well, if it was in Rifleshooter magazine it must have been true right?

A .350 BC is not going to cut it on the HP range. The 6.8 will make a good short to med range cartridge, but some of use are looking for better wind bucking at longer ranges. We may not have the same energy at short range, but for target shooting we do not really care. Energy at longer ranges will be greater due to the higher BC.

The original question was if anyone was making any wildcats on the 6.8 case, I do not think Elk Hunter was looking for an argument on the merits of the 6.8 cartridge. I offered my experience designing and shooting a 6mm based on the 6.8, that is all. If you want a 6.8, then by all means you should get one.

John