1886 Warm Loads

[1972RedNeck]

Miroku 1886 45-90. 405 grain cast bullets loaded to 2.81" in 45-70 brass. 65 grains of IMR 3031. Stiff recoil, shoots great. Super easy extraction. Remington 9 1/2 Large Rifle primers.

Any reason I shouldn't bump it up a little more? 67ish grains would be a level full 45-70 case...

[Drawdown]

Certainly no experience with 45-90 or any straight case. But when I first started reloading for my 30-30, the powder I started with was 3031. It's good in 30-30! But when I started trying to even near max, the stuff scared me. Big velocity spreads between carefull equally loaded cartridges, and at same point accuracy goes kablooie! Similar in a 30-06 later, so now I have no use for it.
Seems for instance, I always found a sweet spot where accuracy and velocity spread where good. But never anywhere near the velocity needed!
In my mind pressure is a good constant push when you get comparable velocities and good accuracy! But when they're not, and you're getting on the hot side, must be some rebounding pressure spikes or something similar going on! Kinda like turning on high pressure water pump when the lines are full of air! I never hot rod with 3031, it's by far the fastest burning powder I've used. But, I know nothing about it in the straight wall cases, so I'm interested to see what you find? I'm just saying i think, Beware!