Having a 1000 6mm 90 grain Speer DeepCurls on hand I would have bought in on the day of announcement and went after hogs .... However Hornady provided me with many challenges such as not providing load data, not having components or ammo readily available, and releasing in the midst of an unprecedented peak in gun sales and component sales.
August 10th 2020 - I have a rifle built, I have 100 rounds of factory ammo at the correct overall length of 2.250", and I have dies and components from my own stock/inventory to reload with.
The last two months have been an excruciating wait and I am super excited to get started with this project.
Tomorrow I will setup a chrony and log velocity data and shoot 5 shot groups from this beefy barrel. I did not have an adjustable gas block on hand so I am hoping Proof's CAMGAS system is optimized for the round as it is advertised to be. I'm doing my part by using an OSS Helix Suppressor which is a flow-through design and has little to no blowback pressure.....
I thought it might be helpful to share some initial brass measurements before and after firing, for these first ones from my 20" faxon barrel.
I have the first 11 cases fired, from the Hornady 105 factory bthp. As from my other post I got 2664 average MV out of these.
As close as I could measure, the case of the unfired round is 1.483", pretty uniform (5 cases). The "B" datum (0.350) measures 1.181" (Saami spec is 1.190-0.007").
The fired, unsized cases came in from 1.484 (1), 1.486, most 1.487 (4), then 1.492 (3), 1.493, 1.496. Datum points (no particular order) were 1.1895, 1.190 (3), 1.1905 (3), 1.191 (5).
I set my Hornady resizing die and sized to datum (shoulder) 1.185-1.186 (about 50-50 as measured), which will be 0.003 for the smallest, to ~0.005 for the majority. The hornady die is a little tricky for me to set so I'll leave it at this -- it's pretty much where I've been re-sizing most brass for my shooting.
I resized the 5 exceeding 1.490 to 1.485, and chamfered all 11.
Now for 2 powder ladders I plan to do:
1, with CFE
1, with 2520. I debated for a bit on this one or use TAC or 8208xbr, but settled on 2520 for now.
I will be using my 103 Eldx and hornady data.
CFE, 27.0, 27.5, 28.0, 28.5, 29.0, 29.5
AA 2520, 26.5, 27.0, 27.5, 28.0, 28.5
One thought has occurred to me from time to time on this topic of temp sensitive powder... maybe that sensitivity differs for different cartridges. And especially the question arises, what about the more, say, efficient cartridge cases.... comes up now because of the powders hornady lists, the ones giving us the MV are ball types like cfe, lever and 2520. Could it be that cfe is less sensitive for this more efficient case.. might even be true comparing 308 case vs say the creed.... anyway, maybe others have some ideas on this.
So, just finished assembling a 20" faxon into some parts I already have, and took it to the range.
First off the 105 factory loads drop in and out with no problem, so that was the first test.
This is the nitrided barrel, rifle gas, 5R rifling,
This baby has some good stuff I will say.
Using the Hornady 105 Bthp's factory.
I topped it off with a 4-12x40 Vortex diamondback tactical I have, on paper at 15 yds, 2 holes touching at 25, and 3 shots, 0.919 CTC, and mind you these were the first 7 shots down the pipe. I think some of that wideness is a bit of woggle that hit me on shot #2 of 3.
Switched over to using my magnetospeed, shots 8-11, 3 were at 0.2" and the entire 4-group, 1.06" CTC (#4 was the flyer).
Speeds and pics posted (I hope).
2665, 2674, 2676, 2643. Avg 2664, SD 15.
I was using a CPD mag, one already broken in for my grendels, worked 100% but I didn't push it, most were 1 or 2-shot mag loads.
Recoil is light, with the VG65 gamma I have on there, it is basically like a 223 in feel. Rifle is probably 9 lb give or take (I haven't found my weght scale from our move yet. ).
I wanted to start a new thread so that other folks can add to it with any information they may find.
I have 500 of the Nosler RDF Ultra High BC HPBT bullets in the 105 grain flavor. The bullets have a BC of .571 much higher than the Hornady 105's at .530. The Noslers are slightly longer than the Hornady's
Hornady 1.226
Nosler 1.246
The Nosler bullet is a longer more slender profile, so I loaded one up @2.250 and chambered it in My Odin barrel that was giving me all kind of trouble with the Hornady bullet getting stuck in the lands and had to either mortar the rifle or use a small soft blow hammer and lightly tap the charging handle holding the release open to get the cartridge out of the chamber.
The Nosler cartridge cambered and ejected with only a pull of the charging handle just as it was designed to do. So now I have a bunch of Hornady bullets that I will probably not use if the Noslers prove to be a better bullet. I need to go shoot some bullets to get some cases to work up a load with these.
I’m having trouble posting my review on this forum. My normal practice is to copy my post from my iPad and post in the forum. When I tried it on this forum my pictures show up but my narrative is not legible. I’ll just link to the same post on the 6.5 Grendel forum.
Got to the range today with the following load ladders and the averages are listed below. If anybody wants to see the complete chrono strings let me know and can send them to you or post them but they just take up alot of room.
A loads were 5 shot strings with IMR 8208 xbr powder, CCI 400 SR primers, hornady once fired cases FL sized with headspace set to 1.185" and trimmed to 1.475". Both the 100 gr and 90 gr. Sierra TGK's were set to CBTO 1.530", neck tension was.003".
The 95 gr SST's were set at CBTO of 1.678"
23.0 gr, avg 2383, sd 10.8, es29
23.3 gr, avg 2412, sd3.1, es 7
23.6 gr, avg 2447, sd 13.3, es36
23.9 gr, avg 2465, sd 16.0, es 39
24.2 gr, avg 2517, sd 5.4, es13
24.5 gr, avg 2547, sd 7.7, es 17
24.8 gr, avg 2566, sd 15.8, es43
25.1 gr, avg 2584, sd 6.6, es 17
The 100 gr TGK's were set to CBTO 1.530"
23.6 gr, avg 2396, sd 22.4, es59
23.9 gr, avg 2449, sd 17.9, es 40
24.2 gr, avg 2475, sd 9.3, es 26
24.5 gr, avg 2494, sd 10.5, es 26
24.8 gr, avg 2516, sd 10.4, es 26
25.1 gr, avg 2550, sd 9.9, es 23
25.4 gr, avg 2574, sd 6.6, es 16
25.7 gr, avg 2570, sd 15.2, es 36
The 90 gr TGK's were set to CBTO 1.530"
23.9 gr, avg 2490, sd 23.9, es 53
24.2 gr, avg 2514, sd 27.5, es 72
24.5 gr, avg 2562, sd 7.3, es 20
24.8 gr, avg 2537, sd 13.9, es 33
25.1 gr, avg 2601, sd 11.5, es 29
25.4 gr, avg 2641, sd 15.3, es 36
25.7 gr, avg 2669, sd 13.9, es 32
26.0 gr, avg 2682, sd 8.0, es 19
At first glance it looks pretty predictable except the 24.5 and 24.8 grs with the 90 tgk, don't know what happened there. Group wise the 100 gr tgk was the loser it stayed 2" or better all the way up the ladder. There is more to be done to find the top velocity but with the 95 SST grouping fairly nice up the ladder I am going to put aside the TGK's for now and concentrate on the 95 grain SST's.
Look over the data and provide some feed back please, I am thinking that 2800+ with the 95 SST is doable but I am a dreamer!
I've reviewed Hodgdon's load data for same bullets and powder for 6mmPPC and 6BR Remington and their data almost raises more questions than it answers.
Figured I'd go about 1 grain heavier than 6PPC data and about 1 grain lighter than 6BR data to get 6mmARC starting points.
However, Hodgdon's data seems off in some cases.
For example, the 6mm 107gr SMK from 6PPC with 28.5 CFE at 48,600 CUP nets 2,702 fps.
Same bullet from 6BR with 30.0 CFE at 49,000 CUP nets 2,632 fps.
More powder. More pressure. Same bullet. Same 24" barrel length. Less velocity?
Doesn't compute.
I suppose one test barrel could be "fast" and the other "slow." That's a plausible explanation, but doesn't really help us rely on the data.
Anyway, screen grabs of Hodgdon data are attached for your convenience.
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![[Image: wDAiRrB.jpg]](https://i.imgur.com/wDAiRrB.jpg)
