I tried some H335 in my cast (340gr) 45-70 loads today to see how well it worked. My starting loads left quite a bit of unburned powder in the barrel so I didn't shoot many in case something was wrong. Should I have used magnum primers or maybe the load is not intense enough for thorough combustion, I don't know. I did not use a crimp on them as they are for a single shot.

I'm not used to ball powders much. What am I doing wrong.

Hope you get some good replys.
I was recommended H 335 for a 308 once and
couldn't get rid of it quick enough.
Apart from black powder it's the only stuff
I've taken a dislike to.
By memory, this character recomended 46g for
a certain wt bullet. I went down from there
trying to get rid of pressure signs, at 41gr
it seemed to be getting worse, so traded the stuff off.

Answer is simple, just crimp them and then see how she goes.
I think you will find they work alot better.
Also ball powder is harder to ignite and using the Mag. primer might help also, if your near max pressure back it down a bit first.

I get the same thing with 3031 and 4064 in my .45/70 until velocities get up into the 1800+ FPS range with 400 grain bullets. It is the mild, low-pressure loads that leave a lot of unburned powder in this cartridge!

There is no unburned H335 in my 7.62X39mm loads!!

Bingo - I loaded up some more rounds with mag primers and upped the charge weight, then applied a roll crimp into the crimping groove on my 340gr bullets.

Results were a lot less unburned powder and accuracy under 2"@100 yards. Recoil was my first indication that ALL the powder must have burned, ie. ouch!

Thanks for the help guys. Now, does anyone make a good recoil pad for the H&R

H335 is an excellent powder but in many cases needs either a filler of dacron, magnum primer, a crimp or all three, in which case it will burn clean...Nothing wrong with the powder when used properly.