Paper patch load development

[Shinhoto]

I've just started paper patching, and I'm curious about how to develop loads for these rounds.
I've got two bullets, dropping from the same 6.5mm mold, one is lead free, and it drops at 135 gr, the other is pure lead, and it drops at 190. The 190 is considerably heavier than any other projectile available in 6.5.
My rifle is a Type 44 Arisaka chambered in 6.5 x 51 (6.5 Japanese). My first inclination was to take about 20% off of the starting powder charge for 160 gr jacketed and to work up from there...
https://imgur.com/a/d2p3McF

[303Guy]

Welcome aboard! :drinks:

Those are long! I doubt the lead free castings will stabilize. What powder would you be wanting to use?

[Shinhoto]

I have IMR 3031, VV N133, and Red Dot on hand.
The lead free should be stable at a ~2000 fps , I've got a fairly quick twist rate (1:200mm).

[303Guy]

I found a load (not an official load - just a load that someone has developed); 30gr IMR3031 with a 130gr jacketed bullet @ around 2000 fps and 30gr IMR3031 with a 140gr jacketed bullet @ around 1800 fps. The developer states that the actual velocity is unknown and that the loads are 'average'. I would treat those as 'some idea' of what to expect.

[Shinhoto]

In what rifle? 30 gr of 3031 behind a 140 gr bullet in my rifle would probably send it closer to 2200 fps.

[303Guy]

That was for 6.5 Jap. It was the only 3031 loading shown. No measured velocity and no measured pressure. Hodgdon only have Hodgdon powder loads for the 6.5 Jap unfortunately. Looking at 'equivalent' powder charts, I too tend to think he has underestimated is velocity somewhat. I do see 30gr H4891 or IMR3031 suggested for 140gr flat based spitzer in one forum.

[Shinhoto]

Here's some data for you from the Lyman #44 loading manual.
http://imgur.com/a/2UWF80p

[303Guy]

That puts things in perspective. So really it's only the boolit shape and size that needs to be considered. Being paper patched it engraves easily but there will be no freebore. The boolit base should not seat past the neck-shoulder anyway so case capacity should not be an issue.

Well, I'd be interested to see how it works out for you. I still look at those long boolits and wonder. The longest boolit I've ever fired was 265gr plain cast in my Brit. It was marginally stable if I recall. I don't remember what made me think it was too long. I may not have been driving them fast enough or the alloy may have been too weak to hold straight. Either way, it would have been on the ragged edge. I didn't pursue those, prefering to limit the weight at 220gr then came down to 194gr. That was to do with throat fit.

On another rifle I found the best fit to be a 208gr round nose. I was making my own molds so I could experiment that way.

[Shinhoto]

These bullets are 1.359 inches long, and are sized to 0.259. I think I'll go with my 20% less than 160 gr starting load for the 190 gr, and regular starting load for the 135 gr.

[303Guy]

I am interested in your results, Shinhoto and look forward to hearing from you.