Complete upper question.....

[LRRPF52]

Its kind of funny the 6.8 spc kind of went through the same thing. spc1 then spc2 now everyone uses spc2. Thankfully the 6.5 grendel and all the variants can safely fire 6.5 grendel ammo! Thats not the case with the 6.8 which is why everyone loads the 6.8 at spc1 levels.

That was a totally different series of events.

6.5 Grendel chamber was developed after well over $10k in different reamers were tested across hundreds of barrels. The final chamber design that went into production has always been sound, and passed SAAMI certification without a hitch.

The 6.8 SPC chamber that went to SAAMI from Remington had some major flaws in it that should have never made it through if you ask many who have followed it, whereas others have said that the chamber was fine, but since people wanted more muzzle velocity, they weren't happy. Compounded with some initial run of Kotonics chrome-lined barrels, and SSA Combat loads, and guns were kabooming like never had been seen before in the AR15.

There were several different reamer designs for the 6.8x43 before SAAMI, one for more speed, and one for accuracy known as the "Murray DMR".

This grumble II business is fueled by laziness and unwillingness to comply with SAAMI, in my perspective, which is typical even in 5.56 NATO, .223 Rem, and .308 reamers from the same source as grumble II. I've had wonderful barrels reamed with what was supposed to be a .223 Wylde reamer or gas gun .308 reamer that would blow primers with factory ammunition left and right. Those reamers came from the same tool maker who concocted the Grumble II.