3031 is an excellent powder for the 8mm, but fast for a 7mm and very, very fast for a 6.5.
The best powders for a 6.5 are in the 4350 to RL22 range. (With 140 gr bullets).
For plinking, the 3031 makes good ammo. If you wanted to load a 6.5 for hunting with 140 to 160 gr bullets (I use the 160 RN) a slow powder will get you velocity and accuracy.
I would never want to even hint that I have anywhere close to your knowledge on reloading.
Back in the day when International Firearms was still in Montreal as a warehouse/distributor, they offered a mixed bag of M96 and M38 Swede 6.5x55 Mausers. Sadly, all of the M94s they once carried were long gone to the US.
Finding 6.5x55 Swede ammunition in Canada was like finding hen's teeth. CIL/Dominion had quit producing it due to lack of demand and sold the equipment to someone in the US.
International purchased a large lot of ammo from Sweden loaded with what turned out to be a slow but excellent flake pistol powder under a hollow wooden bullet. This stuff only came in 2000 round crates and it came with loose, pulled 160gr cupro nickel bullets packaged into 100 round bags. It also came with enough Bofors #44 powder to load all of the fmj bullets into the cases.
This meant the all of the wooden bullets had to be pulled/discarded and the flake powder dumped into containers. Most people dumbed all of this excellent powder. What a shame, especially if they had pistols that fired heavier bullets. I wish I had more to try in one of my 45-70 rifles.
Anyway, the #44 Bofors powder was quoted as being 5% slower than IMR3031 and that IMR 3031 loading tables would work. They also included some now crumbling loading tables for the bullets and powder put together by old Tom Higginson. I miss him.
The loads they supplied were good and also accurate. They gave about as much velocity as other loads and were within a grain one way or the other of IMR 3031 in the #45 Lee reloading manual.
One thing about the 6.5 in just about any case, it can get to the HOT zone very quickly and without a lot of indication that it is getting there. I seem to remember you commenting on this before as well. Truer words were never printed.
I have a lovely 6.5-06 with a 1-10 twist rate. I hoped the slower twist would allow me to get more velocities with 140 grn bullets, without getting to dangerous pressures. No such luck. I have used everything from very slow powders to intermediate range powders and velocities are not significantly different than those I can achieve with the 6.5x55 without running into similar problems that Ganderite ran into, such as loose primer pockets.
Maybe he can explain it better but all I can deduce is that the bore of any rifle can only burn so much powder efficiently and the smaller the bore the faster the saturation point is reached. ??????
