IMR 3031 vs 8208 for .308Win

Check loading data in Hodgdon website and compare. Also look at IMR 4895

All your questions about velocity and pressure are listed in your manuals or on the manufacturer website. Also for a quick reference use a Powder Burn Rate Chart. They are listed by fastest to slowest.
From what I've read and the people I talked to when working up loads for my .300 Savage (Parent cartridge and predecessor of the .308 WIN) that with the .30 calibers HIGH VELOCITY does not equal HIGH ACCURACY. I've been given reccomendations that a heavier bullet and a slower burning powder are best for accuracy.
I recently read and articel and forgive me for not being able to find the link or quote it exactly. But it was to the tune of: Accuracy in .30 caliber bullets at long range is greatly affected by velocity. Causing a bullet to go sonic or super sonic decreases its overall accuracy due to the affects of the air pressure change entering the sonic/supersonic speeds and then again when it comes out of the S/S speeds. It is more beneficial to have a heavier bullet that is not subjected the the entrance and departure of the S/S speed fluctuations.
I currently use 3031 in my .300 Savage and it was again reccomend to me that I use a slower powder to tighten up my groups at 100 yards or greater. It doesn't matter how fast the bullet gets there as long as it accuratly hits its target when it does.

As a practical matter, IMR3031 was a favorite for use with168 gr Sierra MKs for use in 300 meter loads. That was back when the Mks were labeled International.

Remington's custom shop at Ilion, NYm used to ship 40X match rifles that were tested with those loads and they shot so well, it would surprise you.

IIRC, a friend of mine bought a new 40X that shot around 37.5 grains and one other rifle shot well in that general area, too. 5 shot groups at 100 yards were always around 0.4" at 100 yards, or better. This load did not seem to do well in skinny-barreled rifles.

Of the 2 powders listed I would probably go with IMR3031. If you are open to a different powder I would go with IMR4064.

Those of us who have been reloading for quite a while, likely have used IMR3031 at some point. It's been my go to powder for 30-30 over the years until recently, and it's currently my accuracy load in my 22-250 using the 52gr A-Max.
The newer IMR8208 has gained a following for it's accuracy, and has the added characteristic of being insensitive to ambient temperature swings. I personally have not used it.

The Hodgdon load tables show very little velocity differences between the two over the range of bullet weights listed in 308. If I was choosing to buy either, I would try the 8208 first because of it's temperature insensitivity. I use a lot of Hodgdon Extreme powders for that reason.


NCsmitty