X-Caliber 6mmAR

[Herzo]

Just a quick review shows RL 16 will require a heavily compressed fill in order to attain similar pressures to Varget/RL 17. Neither Varget nor RL 16 attain the velocities of RL 17. Just as a note, my comparisons are based on a 107 grain SMK @ magazine length.

[mopar_4life]

Maybe H4895 is better? I just would like to find a temp stable powder that would be good. Maybe I just need to buy QL and see

[soloelcap]

This cartridge is based off the PPC case. The powders for the 6PPC with heavy bullets work, Varget and CFE being about the slowest. I'm not sure how you would figure that RL16 and RL17 would be good choices? Read through the threads on this variant, CFE, 8208, H4895, PP2000 are the go to powders. For long range work nobody I know is shooting anything above the 105 Hybrids in match rifles and not loading to magazine length either. You really don't need QL just look at what others are using.

[Herzo]

I understand the comment about RL17, but when dealing with a 28 inch barrel, I have plenty of time to take advantage of the slower powder. Additionally, RL 17 seems to provide an additional 75 - 100 fps at lower peak pressure over any of the other powders that you list.

[mopar_4life]

My barrel will also be very long. 26 inches with a +2. Gas system. Slower powders might be good for me also. I just like the Temp stable powders.

[Herzo]

Finally have found time to see what I can do with my setup. Loaded a range of RL17 behind a 110 gr SMK and a 105 gr Nosler CC. All loaded 0.010" off the lands.
All 5 shot groups were less than 1" with the Nosler producing a 0.68" @ 2680 fps and the SMK making 4 shots in 0.48" @ 2835 fps(!) - a called flyer opening it up to 1.02". No pressure signs were seen.
Before going much further, I am going to work on my rest - (what I have now does not nest well) and swap out my trigger to one with a 1.5# second stage. Then I need to work on me.

[Lemonaid]

Nice job and I am looking forward with interest to additional reports! How many grains of RL 17 were in your test loads?

[Herzo]

28.5 gr to 30.0 gr. I'm convinced that the longer barrel allows a full burn of the RL17 while keeping the pressure down. Weather permitting I'll run about 4 loads @ 200 yards tomorrow.

[mopar_4life]

Fantastic, how did it go?

[Herzo]

Nothing really outstanding, everything was 1 moa with 1 load at 3/4 moa. Looking for 1/2 or better. Installed a Hyperfire trigger with a 1-1/2# second stage but didn't really get it broken in. Trigger has real promise, but it was inconsistent- that may have been part of the problem. Came home and dry fired it a few hundred times, it is feeling more predictable.

[mopar_4life]

That’s alright sometimes. I’m will also running a hyper fire trigger in my AR. I’m gonna be trying the Vapor Trails 103gn bullets (Automated) over h4895. That’s what I’m planning that is... of course out of my 26 inch barrel I’m hoping for some decent velocity and groups. Whenever it finally gets done.

[Harpoon1]

24" Bull, 11 degree crown 5r 1n8

“1n8” ?

Was that their (X-Calibers?) recommendation?

[Highbrow]

1-8 twist is fairly standard for 6 Grendel/6mmAR