What are the new developments with 6.8

[mshootnit]

There is the 6.8 SPC, Spec II and now is it true that there is a 6.8 spec 3 or 6.8X43? If I am going to give this a try which upper to get? I don't want to get something that is immediately obsolete that I can't get ammo for.

 

[68wj]

There is the 6.8 SPC, Spec II and now is it true that there is a 6.8 spec 3 or 6.8X43? If I am going to give this a try which upper to get? I don't want to get something that is immediately obsolete that I can't get ammo for.

Haven't heard about the SpecIII yet, but that would be an interesting addition to the collection of chambers that already exist. The 6.8x43 already exists and is the brainchild of AR15 Performance.

Now, before you get too concerned, all of these are variations to chambers that accept the same cartridge. It is well accepted that there are SEVERAL chambers for the good 'ol .223 cartridge, but some go nuts when discussing the 6.8.

As brief as I can make it:
6.8 Remington SPC - SAAMI chamber dimensions by Remington. Criticized for having too tight of a throat and reaching max pressure too fast. Still good in its own right. Can use ANY commercially available ammunition except Wilson Combat and SSA Tactical Loads.

6.8 SPCII - The idea of the longer throat is applied and it is argued that higher velocities are obtainable within safe working pressures. Can use any commercially available 6.8 SPC ammuntion.

6.8x43 - Chamber developed by AR15 Performance in an attempt to still allow maximum velocities for the cartridge while increasing accuracy potential. Can use any commercially available 6.8 SPC ammunition.

Others - Other companies have used similar chambers to the SPCII but called it something else. Noveske's Mod 1, RRA's SAAMI II, etc.

 

[mshootnit]

68wj what are some good spec 2 uppers to look at assuming that the 6.8X43 is proprietary. I was thinking about 18"

 

[68wj]

The 6.8x43 isn't proprietary, ARP is just the only one using it right now since they developed it. They make a very good product that consistently gets good reviews (I don't own an ARP 6.8, so don't have first hand experience). Regardless, if you want to stick to SPCII chambered 18" uppers, Bison Armory comes to mind. For recognized production names, Armalite, Bushmaster, DPMS, Rock River Arms and some others are good, but I think they are all 16" (which isn't bad as the extra 2" won't make much difference).