Please rate these powders for bore cleanness

[tacotime]

I'm looking at mid-range loads for 45-70.  I shot some factory and some hand Reloder 7 loads with 405 grain JSP bullets.  Bore was very dirty after a few rounds.  Was this the REL7?

Of the powders I hear for 45-70, could you rate these for clean bores, from cleanest to dirtiest?

RE7
IMR3031
IMR4198
IMR4320
2400
IMR4064

Thanks!

[stimpylu32]

tacotime

A lot more comes into play than just the powder as to weather it is a " Dirty " powder or not , the charge ( heavy or light ) , the crimp ( or lack of ) , the primer ( standard or mag ) , all these things will affect the bore to some extent .

Of the powders you listed I find that none are worse than any other when compaired " apples to apples " , so your " Dirty " may not be the same as mine .

stimpy

[Catfish]

I`m with Stimpy. Who cares about the residue. I use to shoot alot of Bullseye powder and nothing leaves more crap in the barrel than it does. But the loads were as cheap as I could and they were super accurate. I patch through the barrel and is all gone, or 1 more round and it`s all gone, but you have a new batch of crap. Don`t worry about it.

[Siskiyou]

In the past I have used a lot of AL-5, AL-7, and 2400 loading +P+ 38 Special loads or if you want light 357 loads with 158 gr. SWC bullets.  Without a doubt 2400 was the dirtest, but the fact I was using standard Pistol primers for poking holes in paper may have had a lot to do with it.

I have fired a lot of Winchester 125-grain factor HP ammunition is 2.5, 3.0, and 4.0 inch barrels.  Without a doubt a funnel of flame ammuntion.  This ammunition was dirty and rather suspect WW296 ball was used in the factory load.  The "assumption" is the factory used Magnum Small Pistol Primers.

I have burned 8 pounds of IMR4320 and I do not consider it a dirty powder.  (300 Savage, 303 British and 30-30.)  I have burned a few pounds of IMR4064 and I do not consider it dirty. I have use CCI and Winchester primers with these powders.

I am agreeing with Stimpy that the application may have a lot to do with how clean a powder burns.  In my youth I burned a lot of powder bird hunting.  The barrels of my double we very dirty after a day of duck or dove hunting.   But applying a little more thought the powder charge is much heavy in the 12 guage.

So does a box of 12 guage equal two or three hundred rounds out of a pistol?  

[mjbgalt]

yeah, 2400 is dirty. otherwise i don't think others have been more or less dirty.

[tacklebury]

I shoot nothing but RL7 in the .45-70 and have a very clean bore that requires only a quick mop out.  I use 46.7 gr. RL7 and get spectacular accuracy and a clean bore to boot.  I've shot upwards of 50 rounds in one go also.   

[Dezynco]

2400 is probably the "dirtiest", I would just call it "smutty".

Try shooting some real black powder in your 45-70 and you'll know what dirty is!

[Javelina]

A largely ignored issue that results in powders being considered "dirty" or "clean" is whether or not they are fired at close to their maximum burn efficiency or not - that usually happens near a given load's SAFE maximum in your firearm.

Stimpy got us on the right track by correctly noting that there are many factors that can affect burn efficiency.  Generally (in addition to the other factors), the closer to a SAFE maximum that your load (or even a factory load for that matter) gets, the more complete burn efficiency becomes - and again, I say "generally," because there are still some powders that will leave more residue than others all other things being equal.

Powder, primer, bullet weight, case size and shape, barrel length, pressures, etc., are all factors that can work either for or against us as far as undesirable residues are concerned, but usually we can minimize our residue problems by loading more toward a given load's SAFE maximum than away from it (i.e., reduced loads).

If you have a powder that performs well, but you would like to see it leave less residue, try loading more toward your SAFE maximum load with that powder if you can find the accuracy you're looking for there - it may very well surprise you with less residue and less unburned powder.

Javelina

[wncchester]

Two things: 

First, Javelina is correct.  Powders are made to burn at a certain pressure. Light loads of anything will leave more unburned 'soot' residue.

Second, whatever soot one round leaves is removed by the next so the bore never gets any worse.  Meaning, it's no problem.

[KansasPaul]

I have only used RE7 in my 45/70 - I load a 420 grain Speer on the upper end of the pressure spectrum. I only use CCI magnum primers - seems to burn pretty clean in my handi-rifle.  Also, one pass with a bore snake and it's "clean as a whistle".

Paul

[84Jim]

Second, whatever soot one round leaves is removed by the next so the bore never gets any worse.  Meaning, it's no problem.

I'm not so sure I totally agree.  I'm not a benchrest shooter, but I know they are fanatics about a clean bore.  The culprit is carbon fouling, which is different than soot.  Soot is soft and black, carbon fouling is hard and black, and does build up in the bore to the point where it affects accuracy.  I know from experience that takes a lot more effort to get a bore clean after 150 rounds than 20. I figure even the cleanest powder is going to cause carbon fouling to some degree.

[BBF]

In my tests I have found that the powders are in thecfollowing order of looking clean. 
                     1. Trail Boss
                     2. Blue Dot & 2400
                     3. IMR 4198 with mid level loads or higher
                     4. RL-7 with mid level or higher
                     Did not try any slower IMR powder , Norma 201 was similar to RL-7