Hodgdon Extreme vs. standard powder

[hunter5325]

Just wondering if this stuff really has less velocity deviation from hot to cold temps.  I shoot mainly Alliant(15,19,22,25) and I've noticed large drops(+/-80fps) in velocity with temp changes of less then 20 degrees.  Do the Hodgdon powders really stay consistant or is it just hipe?  I can live with smaller changes in vel. but not anything close to the triple digits.  Any experience is appreciated.  Brett

[Luckyducker]

I don't have chronograph data but I have used two Hodgdon Extreme powders and the H4831SC seems to be consistent in differing temperatures as far as POI as I have shot this powder in a couple of different rifles/calibers and they hit exactly the same in really hot vs really cold.  On the other hand I have shot a little H4895 in 22/250 and when the temp gets up shooting a load that was fine in colder weather the pressure starts to increase and primers flattened and action was stiff.  I like Hodgdon's 4895 but I am not as confident of it's temperature insensitivity as I am the H4831.

[MnMike]

I shoot summer (100 degrees) and winter (-30 degrees) in Minnesota and when i was developing loads for my 7-30 Contender I settled on Win 748. Then it got real cold. Varget was not quite as good in summer but in winter the 748 did not do well, and the Varget stayed the same. On my chrono there was a 100fps loss with the 748 and almost none with the Varget. This was not a scientific test - just a couple of trials. Since it gets cold here during hunting, I go with the Varget.

mike

[fastbike]

Your experience matches the Hodgson tables for velocity variation w/ temperature.

I shoot summer (100 degrees) and winter (-30 degrees) in Minnesota and when i was developing loads for my 7-30 Contender I settled on Win 748. Then it got real cold. Varget was not quite as good in summer but in winter the 748 did not do well, and the Varget stayed the same. On my chrono there was a 100fps loss with the 748 and almost none with the Varget. This was not a scientific test - just a couple of trials. Since it gets cold here during hunting, I go with the Varget.

mike

[Questor]

I too shoot in Minnesota, which can be 95F in the summer and 0F in the winter (actually colder, but that's as cold as I ever shoot in). I have settled on the Hodgdon Extreme powders as my powders of choice because they do seem to work as advertised. I have not done extensive testing, just enough comparison to such powders as Winchester and IMR to see less variation with the Extreme powders. They are also good powders for their other qualities. Alliant Reloder 15 is also relatively temperature insensitive.

The tests I've actually measured with a chronograph have been from about 35F to 90F.

Keep in mind that the gun itself changes size as it heats and cools and you can expect some variation.

When I first started using them I'd do my load development when it was hot, then try the same loads during the winter.