Powder residue in barrel 45-70

[rhargrove]

I'm loading IMR 4064 powder 48 grains, 300 grain Midway bullet, Mag Tec large rifle primers. I'm having a problem with a lot of powder residue left in the barrel after every shot.
Do I need to change powder, use a hotter primer, heavier bullet, Less powder. I try to keep my loads at 1600 fps or lower......Any suggestions.

 

[Alk8944]

Try a faster powder first, 4759, 5744, 4198 or 4227. These are far better matched to a .45-70s pressure level. 4064 is just too slow, and using less will make your "problem" worse, not better. You will use a lot less of any of these to get the same performance level too! Your load is probably only developing 15,000 PSI or so, way too low for any IMR series propellent to burn efficiently.

Start casting bullets too. A .45-70 is one of the best for lead bullets.

 

[shovelwrench]

Just an observation, I have no experience with the 45-70 or 4064.

Normally a big charge of slow powder requires a magnum primer.

 

[shovelwrench]

Curious, where that data came from?

 

[steveno]

I don't load that hot for my Ruger #1S in 45-70 so the powders I have had the best luck with is Unique and 2400. my 300 grain hp load is about 1,450 fps using Unique. the 405 grain sp load is about 1,550 fps using 2400. you can get a lot more velocity with those bullets using other powders but they aren't much fun to shoot in a #1.

 

[Skip Sackett]

rhargrove,
Welcome to the forum.

I'm like shovel on this one. One thing I can say though, unburnt powder usually means a lack of pressure. Your bullet is a bit light for the caliber and the powder a bit slow.

I went to the Hodgdon site to see about the loads they suggest. The slowest powder for the heavier 400gr bullet is H335 and that is still quite a bit faster than IMR4064. In fact, the powder they suggest most for modern rifles is IMR4198.

So, like I said, it would seem that the pressure is too low for the powder to work well.

Recheck your loading data to make sure your combination is right. If not, change your components.

After further investigation:
I did find a load for IMR4064 and a 300gr bullet. It has a much higher charge weight than you are using. The minimum charge is double digits over what you are using! The problem being is the velocity is 200fps over what you are trying to achieve.
What firearm are you trying to shoot this out of?

 

[amazingphotos]

Try real powder!

In 40-65 and 45-70 I only use ff. Clean-up is easier than with any "fad" (smokeless) powder and no bore leading ever.