Loading Data Error?

[onelastshot]

I've been reviewing the Barnes loading data information for the 6.5-284 Norma, using H4831sc. For the 127-130 grain bullets, the maximum charge posted using 4831sc is 50.6gr. For the 140gr bullet, (10-13 grains heavier) the maximum charge posted using H4831sc is 51.8gr.; this is 1.2gr higher then the 127-130 weight bullets. Question; how can the heavier 140 grain bullet have a 1.2 higher maximum powder charge then the 127-130 weight bullets? Is this a printing error or, does the BC difference in the bullets (or other bullet design differences, or even the different COAL) permit the higher maximum charge?

 

[CJ6]

Bearing length of the bullets. The heavier bullet may have a shorter bearing length. Hornady has the same thing with it's ELD-M bullets, meaning heavier bullets have higher charge weights than some of it's lighter bullets.

 

[onelastshot]

Bearing length of the bullets. The heavier bullet may have a shorter bearing length. Hornady has the same thing with it's ELD-M bullets, meaning heavier bullets have higher charge weights than some of it's lighter bullets.

Thanks

 

[ronemus]

The particular lot of powder, bullet, brass, and test barrel factor in as well; that's why the mantra is start low and work up.

 

[Bill Norris]

What we have to remember about Load Manuals is the data is only a guide that was created with a particular rifle, barrel, chamber design, and the various lots of powder, primer, and bullet. The atmospheric conditions at the time the testing was done comes into play as well. And the bullet bearing surface as mentioned will dictate max. loads as mentioned above.

 

[onelastshot]

Taking into account that different lots of powder can result in different pressures and velocities, would you recommend mixing the old bottle of powder with the new one to minimize differences?

 

[Bill Norris]

Taking into account that different lots of powder can result in different pressures and velocities, would you recommend mixing the old bottle of powder with the new one to minimize differences?

I normally wait and dump the last few grains from one bottle to the next full one.

 

[M-61]

Taking into account that different lots of powder can result in different pressures and velocities, would you recommend mixing the old bottle of powder with the new one to minimize differences?

“Loading Data Error “, really got my attention. Thought someone had found a mis-print in a reloading manual. I marvel at the proof readers.
Furthest from your title.
2nd: I would not advice anyone to mix anything . I have NO idea what they are really doing or mixing.