Home Forums Reloading Big Game Rifles Hodgdon 4831 sc metering

SodFarmer,

You're welcome to your opinion, but with a good temp-resistant powder and a tuned load, plus or minus a couple-three tenths isn't going to make any difference in a big game cartridge, even way out there. This has been proven over and over again.

There are little things that make a big difference in handlading, and there are little things that don't. This is one that doesn't. If you feel better being anal, then for sure that's your prerogative.

I would be very interested to hear about any hard data you have involving, say, plus or minus 1/4 of a grain of powder at longer ranges. I've shot a bunch of ammo loaded with H1000 out to 700-800 yards, all thrown from a measure into 6.5-06 cases, and haven't found it. And this rifle will put three rounds into 1/2 MOA out that far consistently.

Mule Deer
I have to admit that I haven't tried it. I have worked up to loads in half grain increments and seen significant differences in POI. The IMR 4831 that I have been using in my RCBS powder measure will vary nearly a full grain between charges. This might be unussual because of my particular combination of powder and powder measure, but that is the combination that I have. If I run across a powder that will throw + or - .3g I will take your suggestion and give it a try.

Since the time that I started this thread, I found the following information in the FAQ section on the "Accurate Powder" web sight:

Most of our powders are not insensitive, and will show some effect at hot and cold temperatures.

However, we test at -40F and +125F and the deviation in most cases are ca 3% to 5% at these extreme levels. Therefore most shooters do not notice much difference under normal practical hunting conditions.

More elaboration on the subject:

Complete temperature stability can only be achieved with tubular extruded powders designs, either with double base (NG) and/or with other coating technologies.

Because the ballistic performance at extreme temperature is completely dependant on the specific combination, it is very difficult to quantify and qualify.

Our standard powders perform very well at extreme temperatures, and usually pass the strict military requirements by a large margin.

This is a subject that often fraught with misconceptions and inaccuracies.

The term is used loosely by manufacturers without qualifying the subject, and is obviously exploited for marketing purposes and perceptions.

The facts are:
�Although powders can be improved, it�s really only possible with advanced coating procedures and additives which increase the cost.
�A particular powder can be improved re temperature stability for certain combinations, within a certain envelope which is specific to the following three main parameters/aspects ◦The caliber.
◦The weight of the projectile/bullet.
◦The performance level.


If any of these parameters/aspects go beyond or outside the intended ratio/s, the results will change and the performance will sometimes be different.

It is also very important that when a comparison is made, that all conditions re weapon i.e. components primer, case, bullet and the velocity are equal, and preferably done at the same time on the same day.



I found this information very interesting because it casts some doubt as to possible down sides to the "extreme" powders from Hodgdon. Could just be marketing, but it could have merrit.

Reloder28,

You got lucky, or the temperature changed, or the air conditions chasnged enough to affect parallax.

There isn't any way 1/10th of grain makes that much difference in a .300 WSM--and 760 is definitely not temp-resistant. Ihave seen accuracy change considerably with exactly the same 760 load at temperatures only 20 degrees apart.