6.8 spc ???

Aznative

New member
I have a question about the 6.8 spc. Wikipedia says, "In recent developments (the period 2004-2008) the performance of the 6.8SPC has been increased by approximately 200 ft/s by the work of one ammo manufacturer and a few custom rifle builders using the correct chamber and barrel specifications."

Here is the link to the above quote:
http://en.wikipedia.org/wiki/6.8_mm_Remington_SPC

Unfortunately wikipedia does not tell us what these improves are. So my queston is this: What chamber specs and barrel specs are used to achieve these velocity improvements. What are the improvements in ammo and are they availbable to the reloader?

Thanks in advance
 
the new improvements include slowing the twist rate from 1:9 or 1:9.5 to 1:10 or 1:11 or on custom guns even 1:12.

the chamber size has been slightly modified as well. the new SPC II or on some custom guns the DMR chamber. these newer chambers are slightly longer in the throat (similar to the differences in a standard .223 chamber, 5.56 chamber, and a 5.56 wylde chamber).

these modifications have greatly reduced pressures allowing for greater velocity to be achieved.


this is something that has drawn me to ordering a 6.8.

this little cartridge still does not have the horsepower or a WSSM AR, but the 6.8 was designed to be shot in short barrels (16") where as the WSSM's need 20+ in barrels to achieve maximum potential.

for what i want this rifle to do the 6.8 fit the bill better than a WSSM
 
Mine has the type 1 chamber and a 1-10 twist and the coyotes dont seem to notice the lack in velocity
IMG_0723.jpg
 
I read an article in the June Guns and Ammo about the 6.8 spc, and what go my interest up was a ballistic comparison chart for the 6.8SPC. They show this cartridge hitting a muzzle velocity of 2,800FPS. The performance of this cartridge is just below a 257 Roberts.

I found and read this article:
http://demigodllc.com/articles/6.8-mm-sp...ms-carbine/?p=1

This article shows it going 2650. It may take a little longer for the ammunition and gun makers to catch up with this promising little cartridge. It does look to be a great small to medium game cartridge.
 
Don't mean to jack your thread but why didn't they use a 6.5(.264) instead of 6.8(.277). The ballistics are better. Are the 6.5s to long for AR15 action? There is also the 6.5 MPC(multi purpose cartridge).
 
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This is from the article in the above link:

"Once the case dimensions were tweaked to fit and work in M4-compatible magazines, the project team quickly turned their attention to bore size. Derivative wildcats from 5.56mm to up 7.62mm diameter shooting bullets from 90 to 140 grains were subjected to a battery of tests, and a sweet spot emerged. The 6.5mm bullets showed the best accuracy and the 7mm bullets were the most destructive, but the 0.277-inch bullets showed almost the same accuracy and trajectory as the 6.5mm and almost the terminal performance of the 7mm. When necked down to 0.277-inch and shooting 115-grain bullets, it provided the best combination of combat accuracy, reliability and terminal performance for up to 500 meter engagements. This cartridge was deemed 6.8 Remington Special Purpose Cartridge (SPC), because 0.277 inch is 6.8mm in metric and .30 Remington provided the parent case. "
 
if you are interseted in this caliber go over to the 68forums everything you want to know about he 6.8 is there. those guys are very helpful and have done alot for the improved ballistics of this cartridge.
 
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