[Unclenick]

Jimro,

I wondered whether you might of had that slow Varget. I got 8 lbs of it at one point and had to relegate it all to .30-06, as the extra case room worked well with it. Back then Brigadier 3032 was still available, and I was having good success with that in the .308 and decided not to change.

I've speculated about the role of ATK ownership in the switch to RL-15 in Federal GMM, but I note that they didn't switch from the Sierra MatchKings to the Speer match bullets, even though Speer is owned by ATK as well. Neither did Lake City. So I assume they tested the RL 15 and found no loss off accuracy with the powder in GMM or they would not have made the change, not wanting to lose the round's reputation. I assume they tested the Speer match bullet as well, but either found the Sierra outperformed it, or felt the Sierra name helped sell the ammunition. I don't know which. What Lake City would gain from RL-15 is higher bulk density than 4064, so you can get more velocity out of it. It's about like 4895 in that regard, but I don't know how the burn rate change under pressure compares to 4895 or 4064.

You can roll the old Federal load for yourself. I've pulled the 168 grain SMK GMM ammo in the past and found it used a slightly compressed load of 43.5 grains of IMR 4064. If you have Federal cases and the Federal 210M Primer, that will copy it. It would be about a grain more in the roomier Winchester case that Hodgdon uses in their load data. That's still just middle load range load, so you can work up from just 5% below instead of the usual 10%. It'd be interesting if that turned out to shoot in the OP's gun and the RL-15 version didn't, due to difference in barrel time.