The Firearm Blog

The 6.8×45mm is an alternative to the 6.8 SPC cartridge that has been getting a lot of attentio. Developed by Larry Kramer of Kramer Defense (They have no website that I could find). The parent cartridge is the .223 Remington / 5.56mm NATO.

Its advantage over the 6.8 SPC is that a standard AR15 bolt face and magazine can be used, and that the case can be formed from .223 brass instead of the obscure .30 Remington.

5.56mm vs. 6.8×45mm.
Photo from Defense Review.

The 6.8 SPC can send a 115 gr bullet at 2625 ft/s while the 6.8×45mm Kramer can push the bullet to 2500 ft/s. Kramer claims that once the round is refined it will be able to achieve 2600 ft/s from a 16″ barrel.

A lot of development has gone into the SPC by Special Forces members and Remington. I think it is likely that they would have tried the .223 case as it would be a logical choice for the next AR/M16 cartridge. I know very little about wildcats and cartridge development but I would guess there was a good reason they went with the .30 Rem as a parent instead of the .223 Rem.

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