Hornady published limited load data

[Trashy]

Saw this afternoon on the Hornady load app that they have released limited load data for the 6ARC.  Data is for the 108 eld-m and 110 a-tip.  They also included velocities for max charge weights of several powders for different barrel lengths.

It’s not complete but at least it’s a start.

Trashy

[6mmARC]

gracias for the heads up...kinda wonder why hornady didn't put at least one load on package of their match load, I believe they did that when they released the 6.5CM initially

[BluntForceTrauma]

Since this 6mmARC load data from Hornady is FREE, I am taking the liberty of posting it here.

[Trashy]

Anybody wonder why when Hornady initially announced the arc, they put it at 2750 FPS from a 24” barrel but their load data specifies Velocities from an 18” tube. My question is why they didn’t publish anything on the 105 bthp, unless they are needing to push the A-Tip. Hopefully there’s data coming on the 95gr. SST and the 103 eld-x which due out in the fall in factory form.

Trashy

[BluntForceTrauma]

It's sort of an industry standard to use 24" barrels to pressure and velocity test loads.

Best way to compare apples-to-apples is to use same-length barrels.

[Jakal]

If this load data is true then I don't see much difference between it and the Grendel. I am pushing a 123 grain SST between 2450 and 2550 fps out of a 20" barrel and a 129 ABLR just a little slower. 2725 fps with a 100 grain TTSX out of a 16" barrel. All M4-based systems.

Primers still have rounded edges on my handloads. When I shoot factory Hornady loads, they all have flattened primers and slower speeds, this holds true with 5 Grendel's I own.

So how is this going to be a better round?

[VASCAR2]

I see Hornady tested Reloader 15 which is pretty close to AR Comp in burn rate. Velocity for R-15 and Varget are pretty low compared to CFE223 and LeverEvolution. This data makes the 6 MM ARC look a lot closer to the 6.5 Grendel with reloading components currently on the market. My 16” barrel 6.5 Grendel get 2425-2450 safely with CFE223. Looks like 6 ARC is only 50 FPS faster with CFE223 with the lighter bullet.

I realize the 6 mm will have better wind drift and BC but in the real world application can I shoot good enough to tell the difference.

[BluntForceTrauma]

We'll see what 6mmARC can do when more reloading has been done for it.

Hornady's book loads used a COL of 2.245. I know I plan to load at least to 2.280 and get another "millimeter's" worth of powder capacity. Anybody know how that translates into extra grains of powder?

[Jakal]

That would probably depend on what size of powder kernels you are working with, Long, medium, short extruded vs flat, ball, spherical and the density of the powder. I would imagine a CFE223-type (ball) would give more powder than say like Varget or AR-Comp (extruded).

[grayfox]

I think most so far on here are serious shooters/ reloaders so I can carefully add...
Hornady loads in the past IMO seemed to be fairly conservative, we'll have to see what actual reloading experience yields when some of us get to try ourselves.
Also, seemed at first a bit odd to me that they spec'd out their data with an 18" barrel... but then again that's also what they do with their grendel loads. Those are spec'd from an 18" barrel as well.
"AR-15 data."

It's also nice to see that they will release separate data for bolt guns.

Still waiting for my barrel.

[Biodsl]

I think most so far on here are serious shooters/ reloaders so I can carefully add...
Hornady loads in the past IMO seemed to be fairly conservative, we'll have to see what actual reloading experience yields when some of us get to try ourselves.

You'd have a 1,000 yard gun if a fellow can safely get a 108 ELDM 2500fps out of a pin and welded 14.7 inch barrel. 
Let that sink in.

[Silverjay]

The data I have gathered so far using LVR with a 20” barrel is consistent with the Hornady table. For both 108’s and 110 SMK’s there is a velocity node about 60-75 FPS below the max load that Hornady lists. I am not sure how to calibrate Quickload to the Hornady data, best I can true it to date the top load from Hornady is over pressure. Anyone know how to drop Quickload pressure while keeping actual cartridge volume and velocity at the same powder charge?

[Lemonaid]

Since this 6mmARC load data from Hornady is FREE, I am taking the liberty of posting it here.

Thanks for the info!

[mikein]

Saw this afternoon on the Hornady load app that they have released limited load data for the 6ARC.  Data is for the 108 eld-m and 110 a-tip.  They also included velocities for max charge weights of several powders for different barrel lengths.

It’s not complete but at least it’s a start.

Trashy

Agreed!  It is a start.  And I was pleased to discover that I had 5 of the powders on hand.  I wonder why CFE/BLK isn't on the list.  I guess there's a limit as to how many powders they can try out.

[kmon]

I would not hold my breath waiting for CFE BLK data for the ARC, I think it will be too fast and not nearly fill the case before max pressure is reached. Hodgdon in their info on CFE BLK says loads below 90% capacity will give wide extreme spreads and it does best near 100% case capacity or slightly compressed.

Generally speaking velocities follow a trend with the same cases necked up or down for different calibers, bullets of the same SD will often achieve similar velocities. It is easy to see this with the 308 and its offspring's. Some of that can be made up with powder selections but things like longer bearing surfaces of same weight bullets and expansion ratios come into play.

[Chev2500]

If you go to Hodgdon's loading data and look at the (few) cartridges listed for CFE black, the 6.8 SPC is the only one close to a 6ARC. With a 110 gr bullet it generates the highest pressure and the 6th highest velocity out of 9 powders for that combo.