DirectDrive
Well-Known Member
And there has been a .243 LBC for some time which is similar to this 6mm ARCLes Baer also had a problem paying the 'Royalties" to AA so he created the .264 LBC-AR. Uses the same boltface as a 7.62x39. I have a Black Hole barrel that is chambered in .264 LBC-AR and it will shoot factory (which I just use to get brass if needed for reloading) ammo just fine.
AA just copyrighted the name "6.5 Grendel" (which is basically a 6 PPC case necked up to 6.5-.264) and charges people a fee to use the name.
Here's a C&P from Ritch at Black Hole Weaponry (11/26/2013)...
Would you be interested in some input from the guy who designed both reamers?
Both cartridges have merits of their own. The 243 LBC will handle the bigger bullets because of case length. But as you mentioned it can have feeding problems. I have to throw this in, once you get the kinks worked out it will feed flawlessly. The other problem with the LBC is head thrust. The LBC is limited to 52,000 PSI and should be held to that limit. Bolt failure is a common occurrence if fed a steady diet of over pressure loads, brass life will also suffer.
Now for the good points of the 243 LBC. The chamber is as tight as possible to increase accuracy. The case is inherently an accurate design, and it will handle the heavy bullets. The chamber from Black Hole has a VLD lead. Brass from Lapua is as good as it gets.
The 6X68 was done because I was looking for a cartridge to shoot the lighter weight bullets with good accuracy. It was intended from the start to be a hunting round. It was after the reamer was done we found out just how good of a cartridge it really is. It will handle all the 6mm bullets, but is at it's best with 90 grains and below. Case capacity is the same as the LBC but because it can take the higher pressures velocities increase with the 6X68. The 6.8 case feeds like a 5.56 so failure to feed problems are rare. The accuracy and velocity from this case was better than expected. As far as a hunting cartridge it is a hit. My son killed a Pronghorn this year at 646 yards with a 6X68.
I've always thought that a 6.8SPC necked down to 6mm would be a hot little number.