H.V. Stent wrote an article called "A Handlaoding Mystery" which was about different manuals having varying load data for the 30-30. He shows how the load data varies by 7 grains between Speer Handloading Manual #7 (with 40 grains) and #9 (showing 33 grains). And while Speer gave the reply that there are bound to be changes between publications, they gave no explanation as to why. And while Sierra, Hornady, Lyman, and Omark all gave answers basically saying stick with the latest data, but Hodgdon's answer was "Some data sources keep loads purposely on the low side. We do this. Some data sources want to keep 30-30 loads super safe, below 35,000, and some crowd 45,000 or more...". But again Speer in their own manuals varied 7 grains between two of their own publications. [see: Handloader's Digest, eleventh Edition, page 97-99]
None the less as powder and primers do change over the years it is always best to use the most current load data available. And even then it still varies from one manufacturer to another, whereby leaving the question still up in the air as to which one should one trust.
I have noticed in the latest editions that Hornady publishes a much lower charge weights than the others which actually come close to one another. For example take the 45 Colt, Hornady's charge weights for their 250 grain XTP with Accurate #5 is 7.7 to 10.4 grains, while Lyman has10.0 to 11.0 grains, while both Western Powders and Accurate manuals show 9.9 to 11.0 grains. So Hornady has a minimum of 2.3 grains below the others, and a maximum of .6 grain below the other's maximum. Now if we are not to go below the minimum nor above the maximum charge weights we would be stuck between the two publications at 10.0 and 10.4 grains.
As these manuals warn that going below the minimum could cause erratic pressures so should we dare start with Hornady's low ball charge weight? Or should we be scared to dare start at the 9.9 to 10.0 grains stated by the others, which is close to Hornady's maximum charge?
Funny how they are all using the exact same bullet and powder with modern pressure testing technology and the data as of this day is all over the place. Yet if Hornady was worried about getting sued they would not drop the starting charge weight so low as to create erratic pressures, nor would the others raise the maximum to such heights above Hornady's maximum.
If they are all claiming 14,000 PSI what is up with this? Well different primers and lots thereof, as well as different cases, and lots of powder could explain things to some degree. And then there is the difference in the exact diameter as well as the grooves within the test barrels too. So Hornady used their own cases (which may have a smaller useable case volume than the other cases involved) and Winchester WLP primers, while Accurate used Winchester cases and CCI no. 300 primers, and Western Powders used Remington Cases and Remington 2 1/2 primers, while Lyman chose Winchester cases and Winchester WLP primers. So none of these manuals used the same exact components in their texting which could easily account for the differences in recommended charge weights. Just the pressures between different primers can be 2,000 PSI alone, and the useable case volumes between manufacturers could easily explain the majority of the discrepancy themselves. It is well known that Federal makes the hottest primers so keep those extra 2,000 PSI in mind if you choose to go that route.
And, while this question will always seem to linger (even though I just explained why here above) as to why are there such differences between one manufacturer's load data compared to other's, simply remember to always start at the beginning charge weights and work up. But as to which one you will believe is best is up to your discernment alone! Plus when making up their mind which data is best perhaps one would do well to see which manual uses the brass they plain on using and stick with their primer choose to boot.
Personally, I went with Western Powders, Accurate, and Lyman's data. I used Starline brass and CCI no. 300 primers.
Yet my advise is y'all do you as I don't want to get sued.
None the less as powder and primers do change over the years it is always best to use the most current load data available. And even then it still varies from one manufacturer to another, whereby leaving the question still up in the air as to which one should one trust.
I have noticed in the latest editions that Hornady publishes a much lower charge weights than the others which actually come close to one another. For example take the 45 Colt, Hornady's charge weights for their 250 grain XTP with Accurate #5 is 7.7 to 10.4 grains, while Lyman has10.0 to 11.0 grains, while both Western Powders and Accurate manuals show 9.9 to 11.0 grains. So Hornady has a minimum of 2.3 grains below the others, and a maximum of .6 grain below the other's maximum. Now if we are not to go below the minimum nor above the maximum charge weights we would be stuck between the two publications at 10.0 and 10.4 grains.
As these manuals warn that going below the minimum could cause erratic pressures so should we dare start with Hornady's low ball charge weight? Or should we be scared to dare start at the 9.9 to 10.0 grains stated by the others, which is close to Hornady's maximum charge?
Funny how they are all using the exact same bullet and powder with modern pressure testing technology and the data as of this day is all over the place. Yet if Hornady was worried about getting sued they would not drop the starting charge weight so low as to create erratic pressures, nor would the others raise the maximum to such heights above Hornady's maximum.
If they are all claiming 14,000 PSI what is up with this? Well different primers and lots thereof, as well as different cases, and lots of powder could explain things to some degree. And then there is the difference in the exact diameter as well as the grooves within the test barrels too. So Hornady used their own cases (which may have a smaller useable case volume than the other cases involved) and Winchester WLP primers, while Accurate used Winchester cases and CCI no. 300 primers, and Western Powders used Remington Cases and Remington 2 1/2 primers, while Lyman chose Winchester cases and Winchester WLP primers. So none of these manuals used the same exact components in their texting which could easily account for the differences in recommended charge weights. Just the pressures between different primers can be 2,000 PSI alone, and the useable case volumes between manufacturers could easily explain the majority of the discrepancy themselves. It is well known that Federal makes the hottest primers so keep those extra 2,000 PSI in mind if you choose to go that route.
And, while this question will always seem to linger (even though I just explained why here above) as to why are there such differences between one manufacturer's load data compared to other's, simply remember to always start at the beginning charge weights and work up. But as to which one you will believe is best is up to your discernment alone! Plus when making up their mind which data is best perhaps one would do well to see which manual uses the brass they plain on using and stick with their primer choose to boot.
Personally, I went with Western Powders, Accurate, and Lyman's data. I used Starline brass and CCI no. 300 primers.
Yet my advise is y'all do you as I don't want to get sued.
