Howa mini-action in grendel to be released in mid-2016

[BjornF16]

IIRC as I was researching hand loads for my Grendel bolt, 58k psi was the number I ran across as max for the brass.

When I did my workup with Hornady 129 Interbonds (see https://www.dropbox.com/s/45bfe3ki85fpx7...ksheet.pdf), I closely monitored brass, primers and velocity as I exceeded Grendel AR max with CFE 223.

I've pondered using Federal GM small rifle primers versus CCI 450 small rifle magnum primers. What do y'all reckon the difference would be?

Edit: Chronograph used was Chrony Beta Master; AA brass was Lapua.