Try someody's 4198

IMR 3031's an old favorite powder of mine in the .45-70, but even with the 400-405 grain jacketed bullets it takes shoulder-bruising maximum loads to get it to burn cleanly. It leaves a lot of half-burned powder grains at trapdoor load levels. That has little to do with the barrel length. At the low pressures involved, the powder doesn't burn completely before the rapid expansion of the gas in that nearly straight walled, short case cools it so the powder effectively quits burning. (With typical rifle loads, something like 90% of the powder that's going to burn has burned by the time of peak pressure, which occurs when the bullet's moved an inch or two.) If you want clean burning light loads in the IMR line, look at 4227. 4198's another good bet, and I suspect it's what's in Remington 405 grain factory loads.

Guys,

To start with I'm NOT trying to use a 45-70 as a DGR

Anybody got a good standared 45-70 load worked up for the Marlin "guide gun". I want to stick with the trap door load levels so I don't get too hot a load in an older gun by mistake.

I am having problems with velocity, well the lack of actually. I'm 400 to 500 FPS less than the manuals, and yes I know they are written by someone that always see things in the "best" light. The shorter barrel (18 1/2 inches) accounts for something like 200 FPS but...

The large amount of unburned powder I'm pretty sure accounts for the other 200/300 FPS. I started with my favorite powder (for 45-70) IMR 3031, and then tried RL7, thinking a faster powder might help. I've also tried hotter (mag.) primers, etc. 400 gr. factory loads seem to work okay.

I'm using 300gr. Rem. hollow points and am thinking the lighter bullet combined with the shorter barrel doesn't give enough time and or pressure to burn all the powder. I do want to use the lighter bullet and the gun is a hoot to shoot

Any help you can give would be greatly appreciated

Roi

I had the same problem with 300 grain bullets and imr 3031. Great accuracy though with 53.5 grains of it. I went to imr 4227 and found good light loads that don't leave a lot of powder residue. I got what I wanted with 37 grtains of Imr 4227 and the Rem 300 HP, pressure in my rifle is so low the cases don't always fully obturate. Accuracy is excellent. I also use Winchester magnum large pistol primers with this powder.