Hodgdon Extreme powders?

[Naphtali]

The weather here has been . . . brisk. Which has lead me to ask: Can I create a load using standard version of H4198 or H322 and load exactly the same using Hodgdon's Extreme versions of these powders and obtain identical performance at identical pressures in very cold weather?

[Three44s]

My assumption when loading is that Extreme powders vary less than regular versions ....

...... all powders vary with temperature variations ......

..... the difference is how much .........

And if I understand your question .......... I would say no ......... those regular versions will vary more .........

It's just chemistry.

Three 44s

[Wayne Smith]

Always drop back and start over whenever you change ANYTHING - primer, powder, case, etc. ! This is just common sense. Changes in chemistry will have a change in results, how much or little I won't know until I check them in my rifle. Use established and tested data sets and make no assumptions.

[Larry Gibson]

The weather here has been . . . brisk. Which has lead me to ask: Can I create a load using standard version of H4198 or H322 and load exactly the same using Hodgdon's Extreme versions of these powders and obtain identical performance at identical pressures in very cold weather?


Not a good idea as mentioned. Using "regular powders" you are using a different lot of that powder. Hodgdon advertises the new "Extreme" powders to have the same burning rates as the old "regular" powders. In fact the do for the most part. The exception being lot to lot variation. Be a good idea to work up with the "Extreme Powder". Shouldn't be difficult as you just need to drop a gr or two and work back in a 1/2 gr increment (given a standard size or larger cartridge) until you match the same velocity as with the old powder. If you are close to max watch for pressure signs.

In my pressure test of Varget, H4895 and H4831SC I've found they do drop pressure/velocity as the temperature drops but not near as much as their older counterparts. They are as good as advertised.

Larry Gibson