Joe,
I think John knows I have nothing againest the Grendel but, he adopted it and feels the need to protect it's exsistence.
I am all about getting all of the performance(accuracy with velocity) from any round.
I think the Grendel just needed a little tweeking, a little slower twist, use of lighter bullets and a super bolt from the start or a Oly. wssm sized bolt.
I suggested a few things to try and Bill A. would hear none of it, He's one of those who can't admit to rushing things a little, the rounds already on the market and there are liability issues with increasing the working pressure of the Grendel just like there are with the 6.8. I can't force people to change their minds about what will or will not work.
I took it upon myself to test a few things with a slightly modified Grendel, I rebated the rim of the case so I could use 6.8 bolts and used a 10 twist cheap barrel. I could get more velocity than with the approved grendel loads but they still thought I was crazy for doing something Bill A. said not to(go over his load recommendation).
At that point I decided to do my own thing and not try to suggest anything on the Grendel site. I just chambered my 5R barrel and modified the LWRC dual spring bolt, loaded up 20 rounds going from Bill As load to a load that would make him cringe.
When I get to to point of seeing swipes I'll back off .5 gr so I don't get brass failure and then load for accuracy. I'm betting my right eye that I can get 2-300 more fps out of the round with no bolt failures.
The pressure test one of the Techs at work did for me shows the brass will flow between 65 and 70k psi. I used the 6.8 at a couple of 3 gun events in the last month loaded to test the bolt and almost every case was showing swipes. I think that was near 130 rounds at pressures close to 65k, Colt does 1 70k proof load so I think the bolts are strong enough for the 6.8, today I'll find out about the modified bolt.