Hornady 10th ed manual

R

reynolds357

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Anyone have one? Opinions?
I just picked one up mainly for the gmx data. Some of the loads in the manual are some of the stupidist I have ever seen. First most glaring example is they have the 6.5 Creedmoor faster than the 6.5x284. the 6 5x284 case is bigger, it has more working capacity, and it operates at the same pressure. All sources have the 6.5x284 faster. Anyone who has loaded for both knows the Creed cant come close to hanging with the 6x284. Everybody but Hornaday.
 
Looks like the SAAMI pressure limits are different. 62000 PSI for the 6.5 Creedmoor versus 58000 PSI for the 6.5-284 Norma. The reduced pressure permitted in the 6.5-284, and the short OALs of the 6.5-284 (due to a short throat in Hornady's test rifle) probably combined to work against the 6.5-284 in Hornady's testing.
 
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BBarn said:
Looks like the SAAMI pressure limits are different. 62000 PSI for the 6.5 Creedmoor versus 58000 PSI for the 6.5-284 Norma. The reduced pressure permitted in the 6.5-284, and the short OALs of the 6.5-284 (due to a short throat in Hornady's test rifle) probably ombined to work against the 6.5-284 in Hornady's testing.
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Interesting. According to my saami sheet, which may be dated, there is no max pressure for the 6.5x284 Norma.
Most other reloadibg guides use 62k psi for it.
 
The 6-284 data is decades old, note there are no powders newer than those used 25+ years ago. I remember questioning this data in the mid-1990s, the max velocity was well behind the 6.5-‘06 and the 6.5 mm Magnum in spite of having almost the same case capacity. But being a wildcat there was no standard chamber so throating etc is unknown. You can find similar odd data in many manuals if you look at enough of them. The OP has hardly discovered something new.


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Not too surprisingly, the number is close to the 56,000 psi established for the 284 Winchester, which has a copper crusher rating of 54,000 CUP. That the difference between the two is is only 3.7% is probably a measuring system artifact. Other cartridges with a copper crusher rating of 54,000 CUP like the 264 Win Mag, have psi ratings above 60,000 psi. The European system seems to be more consistent at capturing absolute pressure differences. The CIP has different ideas, though. They use 4,400 bar (63,817 psi).

That difference of almost 6,000 psi is within the SAAMI MEV (maximum extreme variation) value of 12,000 psi. It is below the SAAMI minimum proof pressure of 74,000 psi. Modern bolt guns should have no issue with the higher CIP number, though if you run into a self-loading or a lever gun chambered for it, I would be inclined to load down to the SAAMI limit.
 
TX Nimrod said:
The 6-284 data is decades old, note there are no powders newer than those used 25+ years ago. I remember questioning this data in the mid-1990s, the max velocity was well behind the 6.5-‘06 and the 6.5 mm Magnum in spite of having almost the same case capacity. But being a wildcat there was no standard chamber so throating etc is unknown. You can find similar odd data in many manuals if you look at enough of them. The OP has hardly discovered something new.


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That is an example. Look at the entire manual and it is full of extreme variance with other sources.
 
Mayhaps they accidentally switched the two?

And if you believe Nosler, then H4350 is fastest in the 7mm Rem Mag. Even over RL25 & RL26.
 
I have Hornady #10. 6.5x284 is not SAAMI spec, they list as one of many wildcats. Max OAL 2.800"

The data for both using 95gr/100 the 6.5x284 had 4 max loads at 3200fps vs one load for 6.5CM. For the 120gr/123gr in 6.5x284 they want you to use 129gr data and for 143gr/160gr they only had 4 test loads for each vs 10 or so for 6.5CM.

The 6.5x284 Norma OAL is 3.228". I shoot 284 long action and I seat out pass 3.200" Berger,Nosler has data for 6.5x284 Norma.

I sure won't worry about it.
 
RC20 said:
Hornady works in a lab with a rifle set that is not the same as

can do what they want, Hornady has liability to be safe.
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Their data is slower than most other published sources for the 6.5x284. I wonder if they are intentionally trying to make their round(the Creedmoor) look more favorable than it is.
6.5x284 140 gr bullet:
According to each source, max velocity is:
Hornaday: 2700
Sierra:2960
Hodgdon:2964
Ramshot:2918
 
Bottom line for me is life is too short to worry about it.

I use multiple sources and not the least concerned Hornady may be stacking the deck. I do know the evil H does not have 6.5 Lapua listed, the dogs.

Anyone wants to can cross check and the push the round out past H recommend and see what they get.

Experience reloaders and target shooters just might do that.
 
Hornady uses the practice of dividing velocities into blocks. It's bound to mean they are having to round things up or down from the midpoint between velocity categories, causing both under and over-reporting of some velocities. I've gone through a good number of their loads, comparing them to other data and found a pretty consistent pattern of them being anywhere from one to nine percent under Hodgdon charge weights and some other sources. There are a few exceptions, but that range occurs pretty commonly. I don't know why that is so, but have guessed that because they are buying powder off the shelf and don't know where the lot they bought might lie in the burn rate tolerance range, they may be making an extra allowance in case their lot is on the slow end. But I don't know for sure.
 
Unclenick said:
Hornady uses the practice of dividing velocities into blocks. It's bound to mean they are having to round things up or down from the midpoint between velocity categories, causing both under and over-reporting of some velocities. I've gone through a good number of their loads, comparing them to other data and found a pretty consistent pattern of them being anywhere from one to nine percent under Hodgdon charge weights and some other sources. There are a few exceptions, but that range occurs pretty commonly. I don't know why that is so, but have guessed that because they are buying powder off the shelf and don't know where the lot they bought might lie in the burn rate tolerance range, they may be making an extra allowance in case their lot is on the slow end. But I don't know for sure.
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I dont know either, but Sierra and Nosler sure show lot hotter in most cartridges than Hornaday.
 
First most glaring example is they have the 6.5 Creedmoor faster than the 6.5x284. the 6 5x284 case is bigger, it has more working capacity, and it operates at the same pressure
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but the Creedmoors were designed by Santa's elves and sprinkled with pixie dust:rolleyes:

that's why they have the 6.5 CM outperforming the .260 Rem which also has more case capacity and equal working pressure. I push 142 SMK's at 2850 with no pressure signs whatsoever out of a 26 inch barrel yet the Hornady 10th has the 143 maxxed at 2700
 
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SAAMI pressure is 62K PSI for the 6.5 Creedmoor and 60K PSI for the 260 Rem. Differences in the SAAMI velocities of those two cartridges are small.

I doubt Hornady is deliberately reducing it's published 6.5-284 data. More likely the results are driven by their choice of rifle, barrel length, powder, and operating pressure (or fired case characteristics/measurements since their data clearly pre-dates SAAMI adoption).
 
interesting because I took those 142's up above 2900 before I started getting some mild pressure signs and I was staying well under Hogdon max load data, that was in a 30 inch barrel though using H4350
 
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