New Rifle/First Loads

[seven6twomm]

[grayfox]

While I don't shoot Lapua, IIRC its case volume is slightly less than Hornady... in any case (even for Hornady brass), the CFE, ARC and 8208 loads all intrude into a questionable range, too hot IMO. 8208 can pressure spike quickly for 123 pills at ~28.5, sometimes less. The ARC loads top out in the book at 28.0 (this from memory but I shoot ARC in 123), and the CFE for 100 Eldm tops out at 33.4.
So, this begs the question, why with a good 22" Criterion barrel do you want to push the limits so much?
Especially for your initial rounds.
And I don't think I would try 8208 at all for a 130 gr bullet.

I advise to steer clear of over-max loads.

[Mesa1978]

+1 on the over-max loads, why even start there, especially with a new barrel/build? I've used 28.1 grains of ARC in both Hornady and Lapua brass with 123 SMK and 123 Scenar with Shilen and Lilja barrels, and see no worthwhile accuracy benefit and do see pressure signs in both. I backed off from this load as the risk/reward didn't justify it in any way.

I have gotten 1 moa groups from 26 grains of ARC in a Hornady case, once fired, with 130 Berger VLDs in a Lilja barrel, YMMV with hybrids and a different barrel.

I have always used CCI 450 primers and FL resized to .286 neck size with Hornady and .288 with Lapua with a Redding S die, since I shoot AR pattern rifles.

These loads are applicable only to my rifles and experiences, I have to disclaim any responsibility for any use by those other than myself. Sorry for the weasel words, but the world we live in today...

[A5BLASTER]

Me personally I would lose the 8208 from the 123 and 130 pills it spikes to fast with heavier pills. Should work ok for the 110 grain pill.

I would use the cfe223 with the 123 and 130 pills. I have only ever used cci450's even in my bolt action. So can't give any comment on the primer your useing.

Ohh don't go over book max loads.

If it's a new barrel, I would run factory rounds through it for the first 100 or 200 rounds. Then start working loads up.

Hope this helps.

[seven6twomm]

Yeah I was having a hard time finding published data for the powders that seemed to be the go-to powders for the Grendel in an AR (8208 and AR-Comp) with these bullets. I don't need to or want to push hard at all and have a lot of powders to choose from. I'll look at this all again and see what I can come up with before I load anything.

[grayfox]

In the industry partners section of this forum go to the AR 15 buildbox part, there is a 2-vol set grendel handbook you should get. Best reloading money ever spent for the Grrr, it has tons of reload data in it as well as lots of other info from the guys who are not only excellent shooters but also deep in the development history of the caliber.

[seven6twomm]