Is it just me or have you all noticed the ridiculous amount of variations in loading data during the last few years.

Alot of loads I've used over the years that were safe by several sources of data are way hotter than max loads from some sources of late.

I guess the powder company's legal teams are trying to add alittle more safety factor.

Oh well, I usually only use the manuals for good places to start anyway. We all know every rifle will respond differently.

Reloader

It may just be powder formulas are changing abit. I know that old IMR4350 is not the same as current lots, nor is Unique or 2400.

Remember that some Winchester Ball powders are the same as some Hodgdon sphericals.
Since Hodgdon also owns IMR I suspect that the recipes if not the entire production will be consolidated into common product in either separate or maybe a single brand containers.

As you stated the manuals are only guides. The loads are only accurate with the exact components and chamber/barrel they were measured in.

The problem is when they are retested for the next edition the lots change, the bullets may have a harder core or jacket, the OAL may have changed. The primers may be of different brand, the chamber/barrel most likely will be new. That along with an industry allowable max variation of 10% max (I`ve been lead to believe. That`s part of the reason behind a 10% drop in charge when working up) in powder lots causes a lot of change in the load between old and new.

Speer now lists Trophy Bonded bullets in their data, Nosler the Accu-Bond and Hornady has added the inter-Bond. I doubt the max charge for a Trophy bonded is the same as a Hot Core. The different companies list all bullets produced of like wgt in one listing, which produces the most pressure?
The powder companies do the similar, they list a generic 180 gr 308 cal bullet in their 300 mag data and then next year change to another. They are now getting more specific in bullet used but their COL, primer, or case may not match the bullet makers when you try comparing ones load to the others.
One thing they all state in their manuals though is the max was max as tested and there is no guarentee your components won`t be higher in pressure.

quote:

Originally posted by Reloader:
Is it just me or have you all noticed the ridiculous amount of variations in loading data during the last few years.

I guess the powder company's legal teams are trying to add alittle more safety factor.

Nah, it isn't that at all.

Have you seen how much difference in density there often is between different lots of the same canister grade powder? Same rifle, same chrono, same day, same components, same charge of the same powder, just from different lots - I've seen a difference of 200+ fps on more than one occasion.

I think the answer to your question is that there are many more variables than just the difference between rifles. Few seem to believe how much difference there can be between lots of the same components, especially powder.
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"Serious rifles have two barrels, everything else just burns gunpowder."