hodgdon load data vs Hornady data

[a1b3rt]

for the same bullet weights (308 win e.g.) I always find that Hodgdon’s min and max are higher than Hornady’s min and max.
I understand that there are variables like bullet shape, neck tension, etc. We are also responsible for our own safety so we need to test recipes carefully, these data are just references….
So why do they have big delta in min and max for the same bullet weights?
Thanks!

 

[Potashminer]

I do not really have direct answer for you - but probably starts with comparing the complete recipe that each tested - type of primer, brand of case, test apparatus, etc. - I always presumed that they reported the test results that they got using their stuff - none of them used my stuff, so their results may or may not exactly apply to me?? It has been stated here on CGN that swapping primers can be like adding or taking away a couple grains of powder - but likely need to be using an actual pressure barrel to show that difference?? I know for sure that another guy's loadings that he has used for years in his rifle, will lock up my bolt solid - he thinks there is something wrong with my rifle - is just different dimensions, inside, I believe - chamber, ball seat, "throat" length, etc. I can not chamber his fired brass, yet both are supposed to be the "same"...

 

[yodave]

one is done in a lab, the other on a computer, one of them has been advised by a lawyer to leave some room for error.....

not all bullets have the same length drive band, not all brands or lots of brass have the same case capacity, not every lot of powder has the exact same burn rate, so lots of variables to take into account when publishing data that millions of people rely on

 

[9.3mauser]

If you compare a 4th edition Hornady manual to the current 11th edition, the loads were much hotter in the older version. I suspect lawyers got involved at some point.

Hodgdon data can be quite fluid too. I looked up a load for .30/06 using StaBall, and when I went back a few months later the data had changed.

 

[350 Mag]

Every rifle/chamber is different as well.



I find starting 2.0 gr below manual and I also cross-reference with Online data....alot of cartridges prefer a certain bullet weight, Powder, and charge weight.

Alot of good reloaders have allready done alot of work.

From that point pay attention to pressure signs and shoot over a chrono.

Pressure signs I look out for:

Velocity above book values.

Stiff extraction.

Ejector swipe or indent on case.

Flattening edges of primer.

 

[IvoB]

I start at the low end and my max load would be their published mid-load in other words I am able to find an accurate load without ever going max

 

[dan belisle]

for the same bullet weights (308 win e.g.) I always find that Hodgdon’s min and max are higher than Hornady’s min and max.
I understand that there are variables like bullet shape, neck tension, etc. We are also responsible for our own safety so we need to test recipes carefully, these data are just references….
So why do they have big delta in min and max for the same bullet weights?
Thanks!

They use different firearms for testing. I have been in Hornady's test cell, sometimes they use a universal receiver, and sometimes it is a particular firearms. The day I was there they were working on the 30-378 Wby for the first time. For that they used a new rifle from Wby. Hodgdon will do similar, but with different firearms. - dan

 

[Potashminer]

If you compare a 4th edition Hornady manual to the current 11th edition, the loads were much hotter in the older version. I suspect lawyers got involved at some point.

Hodgdon data can be quite fluid too. I looked up a load for .30/06 using StaBall, and when I went back a few months later the data had changed.

I have read a few USA writers - John Wooters (?), or maybe Bob Hagel (?) for example - saying he wishes he could call back some previous loads that he published - at the time he thought they were okay, apparently, but thinks differently about it now. So if you only read his original article, you would believe all is good, even though the guy now has better information than he had then. So, could be cautious lawyers, could also be more accurate pressure measurement. John Barsness writes that many earlier reloading manuals produced without using pressure testing machines - but they sold, because people bought them. I notice most all manuals on first or second page dis-avow any previous information that they might have published in the past - so much for "relying" on older data, in preference for newer information.

 

[Potashminer]

I have also posted previously of finding errors in data - was Nosler on-line - for H1000 powder in 7mm STW - was same numbers printed for both 160 grain and 175 grain bullets - I did notify them, but never did get a reply - and I see their Nosler #9 Reloading Guide has the exact same error (p. 438 and p. 440). Pretty much to me a good reason to get information from more than one place. A correspondent had randomly picked the Start load for 175 grain bullets - much more powder listed for "Start", then several other manuals, or previous Nosler manuals, show as Maximum - froze up his bolt pretty good, I understand. Nosler showing exact same Start load and Maximum load for both 160 grain and 175 gain bullets with that powder. There were compounding issues - using 8mm Rem Mag brass, a "custom" barrel with much smaller than SAAMI neck area, etc., besides the loading manual information.

 

[alpining]

...Pretty much to me a good reason to get information from more than one place. ....

Amen.

Errors happen, and sometimes they make it all the way to print. I always use the average starting load from as many different MODERN sources as possible.

What's the gain in using the hottest published starting load anyway? A few bucks worth of projectiles?

 

[gyppo]

I started reloading years ago with the .45-70 and a Hornady manual. After comparing to the Hodgdon data I began to suspect Hornady was up to some marketing shenanigans with their loads. They were loading 300 and 350 grain bullets very light but seemed to be pushing their FTX bullet a lot closer to Hodgdon data.

Then in another possible marketing move, in .450 Marlin (which is a proprietary Hornady/Marlin creation) they were showing better velocities than 45-70, yet using a shorter barrel. Hodgdon on the other hand showed a slight edge for the 45-70 in the same barrel length (which makes sense since the .450 has lower case capacity, despite slightly higher operating pressure). Almost as if to say if you want to load hot .45 rifle rounds, either get our .450 Marlin, or load your .45-70 with our FTX bullet.

Maybe I read into it too much, but it does look a bit suspect.

 

[Potashminer]

Was similar point in John Barsness article about 9.3x62 versus 30-06 - he could not agree about the pressure limits, since he had identical rifles, by same maker, one in each cartridge - why would pressures have to be different? So, he did some stuff and created his 9.3x62 loads - then got them pressure tested at Western Powders lab - at or slightly less than 30-06 levels, but significantly above 9.3x62 levels. I think his "trick" was to be able to verify what pressures that he was at - did not rely on "home reloader" clues - was done in a pressure lab. I think the pressure difference was only like 3,500 psi or similar - but 100 fps or more difference, as result.

Some will argue that the traditional 9.3x62 was just fine as it was - modern people want more speed, apparently - have troubles with notion that "more speed" might create its own problems ...