Hornady Factory OAL Concerns

[grayfox]

Sort of looks that way.
But golly gee, you ream a barrel and then try some factory loads...
lather rinse repeat...
what's hard about that?

[Dino11]

Don't think we've heard from cmmg or BA barrels, if someone has one and could report that would be a help.

I have had a BA barrel on order since June 12, still have not heard anything about it.

Faxon has one to, I have three Faxon barrels and the two that are assembled shoot pretty damn good, both of them are pencil barrels, one 16' in a lightweight build 4 lb 14 oz without optic, and a 10.5 pistol that is a tack driver.

Here is a picture of the lightweight, it now has a 1X10 LPVO on it Magnesium upper and lower and a bunch of other lightweight stuff.

[grayfox]

cool. I meant the 6mm Arc's however... the other calibers/mfrs should all be gtg on chamber sizing.

[Trashy]

My barrel is a cmmg, the only 105 grain bthp’s I had were the factory rounds and they are gone thank goodness. I provided what measurements I could in post #14. Sorry

Trashy

[grayfox]

Looking at JRB, the livestream/twitch replay he has now on u-tube... anyway at about 0:59:00 or so he gets into loading up his odin barrel (18") 6 Arc, and finds the bullets are hitting his lands. He says it's not a hard-stuck case (they manually extract) but definitely seeing land grooves onto the bullets. And he repeats on-air, a txt sent to him by another shooter that he also had stuck rounds.
These are all with the factory 105 Bthp's.
So Odin definitely seems to have an issue with short throat or something.

[Pig_Popper]

Interesting , Dino11 how are you wearing the bullets to 2.210” ?

When I pulled down the 1 factory load to take the measurement with the powder was already compressed greatly...

What powder and charge weight are you loading with that shorter COAL ?

[grayfox]

Followup on the JRB stream... the 105's are shooting, his labradar is showing ~2630 ft/s.

[grayfox]

Update 2 on JRB replay, at the start of his second round of 5, for groups, the round stuck in the chamber, doesn't seem to want to come out easily..........
The other shooter he mentions who had this problem is "ozark".

[Dino11]

Interesting , Dino11 how are you wearing the bullets to 2.210” ?

When I pulled down the 1 factory load to take the measurement with the powder was already compressed greatly...

What powder and charge weight are you loading with that shorter COAL ?

At 2.210 the bullet is just barely touching the land. I have zero issues loading them to 2.200. When I spoke to Odin they told me that they were using Hornady tools and reamers to make the barrel. And that Hornady said to load the rounds to 2.200. I would love to get my hands on a box of the new rounds getting ready to come out and see where Hornady is loading them at, they already knew the first batches were to long. They should have recalled them, they are causing some issues getting stuck in the chamber. They do fire and extract fine, but non the less it is a problem.

The rounds I loaded last night were 25 grains 8208XBR, one of the lowest grain loads from the load data Hornady provided.

[Pig_Popper]

I watch JRB just now

I feel for him I really do

Trying to make it fun and educational for viewers with all the tech and streaming and then the new rifle won’t work right - what a kick in the nards...

Odin looks like not a good choice with factory 105s - I hope they get it sorted quickly.

[BluntForceTrauma]

If both Dino11 and JRB are using Odin barrels — and if JRB's friend Ozark is, as well — then it sounds like a barrel problem rather than a SAAMI spec problem for 6mmARC.

Whether it's Odin or Hornady, I'm sure it'll get resolved.

[Pig_Popper]

I can tell you at 2.250” the 105 bullet is way down past the bottom of the shoulder of the case / I’ll see if I can upload a photo

At 2.200” your powder capacity is going to suck

If you want to run heavies (reloading) id get Odin to fix that barrel

   

   

[Dino11]

If both Dino11 and JRB are using Odin barrels — and if JRB's friend Ozark is, as well — then it sounds like a barrel problem rather than a SAAMI spec problem for 6mmARC.

Whether it's Odin or Hornady, I'm sure it'll get resolved.

I just got off the phone with Tim at Hornady technical support. There are two barrel manufactures that have short chambers. But... this is not going to be a problem as the new rounds are going to be loaded at 2.200 right from Hornady. So this will give me a short .010 lead jump. As far as compressing the load this will only help accuracy as it eliminates any air pockets in the case. The rounds take very little powder to begin with, and Hornady said that the shorter chamber and the short lead jump combined with a more compressed case charge is only going to add to the accuracy of the rifle.

Although I could possibly see a problem with some powders that take a higher amount of grains and possibly some extruded powders that have a tendency to fill the case to a high percentage. They also stated that the shorter  and compressed rounds still are within the Sammi pressure range.

[BluntForceTrauma]

Hornady's reply to you is basically good news and sounds workable, but I would tend to disagree that it is the BEST solution.

I WANT the extra powder room and velocity potential or, conversely, pressure reduction that a 2.260 COL offers overs a 2.200 — and 2.280 is even better.

There is beginning to be some debate whether short jumps to the lands are ALWAYS desireable.

Check out this article on the PrecisionRifleBlog. Click <HERE>.

Article basically says that while short jumps may be accurate initially, they erode fast, and that going with a longer jump to begin with keeps accuracy more consistent — and consistency is part of accuracy — for a longer period of time.

[Dino11]

Hornady's reply to you is basically good news and sounds workable, but I would tend to disagree that it is the BEST solution.

I WANT the extra powder room and velocity potential or, conversely, pressure reduction that a 2.260 COL offers overs a 2.200 — and 2.280 is even better.

There is beginning to be some debate whether short jumps to the lands are ALWAYS desireable.

Check out this article on the PrecisionRifleBlog. Click <HERE>.

Article basically says that while short jumps may be accurate initially, they erode fast, and that going with a longer jump to begin with keeps accuracy more consistent — and consistency is part of accuracy — for a longer period of time.

I know exactly what your saying, I am not one to load for velocity over accuracy unless it's needed. This round already has some distance behind it. I will have to keep an eye out when loading these. I will run it through Quick Load and see how much volume I am using up with various powders, as I have a whole slew of different stuff I can use. I am sorta a fan of ball powders and finely extruded as well. My favorite being H322, stuff is just one of the cleanest burning, most accurate, temp stable powders I have used. And the benchrest 6mm folks use this as one of the most favorites as well, and it's easy on your barrel. I use it exclusively in my precision AR's.

At least I'm doing the leg work and getting some useful information that is not being published anywhere on the internet or in publication that I have found. At least the folks behind this are will to stand behind their product and help people out like you and me. Tim was very helpful and passed on information that a lot of companies would have said nada. And he did not try and BS me and get me off the phone, kudos to Hornady.

[grayfox]

Agreed. Not optimum but good to know that length is safe.
I also second what krys is saying, having the larger case volume and even more powder you still keep pressures ok.
I think Odin should bump their leade out 20 thou but that’s my opinion...

[Dino11]

Agreed.  Not optimum but good to know that length is safe.
I also second what krys is saying, having the larger case volume and even more powder you still keep pressures ok.
I think Odin should bump their leade out 20 thou but that’s my opinion...

If this does not work out for me Odin will be seeing my barrel back to either fix any issues or replace it. I really don't want to do this. This barrel just flat out shoots like it cost 2K. I might not get the same accuracy out of a replacement or of they start changing the chamber specs. I will take this one that I might be limited on case capacity with, over one that I can hot rod and get better velocity. The whole point in this build was being able to hit my target at the POA. And thus far is has proven to do that. I will defiantly chrono the rounds next time out, wasn't able to do that the first time. The brown truck guy just dropped off my Nosler RFD 105's These suckers BC at 571, they look like they are longer and skinnier than the Hornadys.

[Pig_Popper]

I’m speculating at this point but my years of reloading experience make me say the following:

There is no way Hornady is going to be able to maintain the approx ~ 29.9 grs of powder AND seat the 105 deeper in the case by .030”.

They’re going to have to fiddle with the load so what will be interesting is keep 20 or so rounds of the current stock and shoot it the same day as 20 or so of the shorter OAL and see what velocity does .

I’m a betting man and I’d say the odds on favorite is less velocity.

As I unpacked the round yesterday the powder was so compressed throughout the case and a lot of powder stuck to the interior walls which indicates the powder was packed in there pretty good.

6 ARC for me is going to be a handload only proposition because of the amount of bullets I have on hand so really I’m not concerned with what Hornady decides but I can tell you I want a longer jump potential because as you vary the bullets some of the 80-90 grain bullets may hit sooner than the 105/108 class bullets ...

[Dino11]

If the bullet is seated deeper and the pressure increases wouldn't you be able to reduce your powder charge to maintain the same pressure as the current spec load for the 108's. I loaded the 108's at 25 grains spec at 2.245, they are now at 2.200 and the pressure is going to increase, max load is 25.3 with the 8208XBR. I will bet that my velocity is going to exceed the 2400fps that load is spec for. I would think that 25 grains would be a max load for the 105's @ 2.200.
I need to go get my laptop and look at Quick Load. But I will say that the load is lightly compressed with 25 grains with both loads.

[grayfox]

As a followup, I calculated the 6 Arc lost case volume due to seating a bullet from 2.245 down to 2.200 (the Hornady recommendation), a depth loss of 0.045".
Using the Saami drawing and a nominal 0.015" wall thickness, I calculate you lose 1.496 grs (of water) case capacity. out of 34.5 total, that's a 4.3% loss of your volume to the deeper seating. 'Course some of that 34.5 is also lost to the bullet's intrusion down into/below the neck.
I hate to lose that much, speaking for me.