Last Updated :: 8/30/2007 1:52:06 PM
Q: What does SPC stand for?
A: Special Purpose Cartridge.
Q: Why was the SPC invented?
A: To improve terminal performance over the 5.56 cartridge in short barreld/AR sized weapons for SOCOM forces.
Q: Why 6.8, why not 6.5 or 7.62 mm?
A: During testing the inventors tested a variety of commercial bullets from 6mm, up through 7.62mm. It was found the 7mm bullets provided the best terminal performance while the 6.5 bullets provided the best accuracy. The 6.8 was a compromise between the two. It provided better terminal performance than the 6.5, while having better accuracy than the 7mm prototypes.
Q: Is the 6.8 SPC just a necked up 5.6?
Q: What is the parent case of the 6.8 SPC?
A: The 5.56/.223 casing just didn't have enough capacity for the larger round. So the designers chose the now obsolete .30 Remington as the parent case. It provides more capacity than the 5.56 cartridge. The 6.8 SPC case is larger in diameter than the 5.56, but narrower than the 7.62x39 so a new bolt had to be developed, one that is stronger than the 7.62x39 bolt.
Q: I heard from a friend that has an uncle who's brother in law works in the Pentagon who said that the military is going to the 6.8 round next week. Is this true?
A: Short Answer: No, but read the next two Q&As for the full answer.
Q: Is the 6.8 SPC going to replace the 5.56 in the Military ?
A: The 6.8 SPC was never inteded to replace the 5.56 for the entire military (though it would be nice), the cartridge was intended for use by Special Operations Forces only.
Q: Is the the 6.8 SPC being used at all by the Military?
A: Yes, it's in limited use by SOCOM personel.
Q: What do I need to convert my 5.56 rifle to 6.8?
A: Barrrel, bolt, and magazines.
Q: Can I use 5.56 magazines?
A: Not really. while they will work for a few rounds, you really need to buy 6.8 SPC magazines to get capacities over 5 rounds.
Q: What is the preffered barrel specifications?
A: You get very little increase over 16" so most people opt for the shorter/handier 16" barrels over the 18" (or longer). Barrel should be 4 groove with a 1:11" twist (to keep the pressure at a minium). Older barrels use a 1:10 or 1:9.5 twist rate as that is what is used for the .270 Winchester and is needed for the heavier bullets of that caliber. While the tighter twist rates can be used, you'll limit your 16" velocities to 2500-2600fps.
Q: Can I make IPSC 'Major' with the 6.8 SPC?
A: This is a sticky one. You cannot make major with standard factory ammo. However, with an 18" 1:11" twist barrel (Ko-Tonics enhanced chamber recommended) and handloading 120gr Barnes solids or 130gr Speer Softpoints (flatbase) you can make 'Major'. (for details see the Reloading FAQ at the bottom)
Q: Where can I find the Technical specifications of the 6.8 SPC Cartridge and common loadings?
A: Right Here: 6.8 SPC Technical Information / Specifications Page
Q: Can I use my 5.56 lower for my 6.8 upper?
A: YES! The 6.8 uses the same lower. There are NO problems (legal or technical) that prevent you from using your .223/5.56 marked lower with a 6.8 upper
Q: What Buffer do I need?
A: The 6.8 uses the same buffers as the 5.56. It will run with anything from the standard CAR buffer to the Rifle buffer (though the ejection pattern will change as the buffer weight changes).
Q: Can you Reload the 6.8 SPC?
Q: Where can I find information on Reloading for the 6.8 SPC (Recipies, Supplies, and Resources)?
A: Information on reloading for the 6.8 SPC can be found right here: 6.8 SPC Reloading Resource & Information Page
Q: Where can I find links to Other Discussions & FAQs on the 6.8?
A: At these locations:
Q: Where can I find 6.8 factory ammo online?
A: These vedors carry 6.8 SPC ammo:
Q: Which manufacturers offer a 6.8 SPC AR-15 type rifle?
A: These do:
Q: Who carries parts & uppers for the 6.8 SPC?
A: Try these vendors:
Q: Can I get a lower marked as a 6.8 caliber?
A: Yes several companies sell lowers with 6.8 SPC markings:
Q: What factory ammo is available?
A: Factory Loads Currently Available as of 29 Aug 07:
Q. What bore cleaning accessories do I need for 6.8 SPC?
A. Any quality, .270 caliber, bore accessory is appropriate. Some use M4/M16 chamber brushes for the chamber.