Is Unique really “dirty” ?

[jski]

I’ve been loading some creampuff .45 Colts using Starline’s Cowboy Special brass, .41 Specials (again Starline brass), and 38 Specials +P using Unique and haven’t really noticed it being any dirtier than other powders. I know it now says on their 1lb jar, “cleaner burning”. Not sure that means anything in particular.

What’s the consensus?

 

[steveno]

Unique burns as clean as any powder but you have to load it to the high end of pressure range

 

[Scorch]

Old Unique was kind of "smudgy" with lower pressure loads. New Unique is about the same, maybe a bit less. I haven't noticed a huge difference. What makes powders burn clean is pressure. higher pressure is cleaner. Lots of powders leave unburnt powder everywhere with lower pressure loads.

 

[Metal god]

I've only been loading handgun ammo for a few years not so I don't have tons of experience on this subject.

I think there are different definitions of dirty powder. When I think dirty powder I think of smoke when fired and lots of residue left over inside and outside the gun. With that as my definition, Unique is a dirty powder along with HS6 but I rarely push them hard. I do have a pretty hot 357mag load using HS6 that does seem to be a bit cleaner burning but it still smokes and is sooty. My guess is pushing unique would clean it up a bit but it's still going to be dirtier than other powders in general.

I like it though; good powder for new reloaders.

 

[Pathfinder45]

Unique is an excellent powder in the 45 Colt when using bullets of normal weights at standard velocities, more or less. It burns a lot cleaner than some others I have tried.
Use genuine Black Powder sometime and you will never complain about Unique being dirty again.

 

[Hawg]

Use genuine Black Powder sometime and you will never complain about Unique being dirty again.

I bought a pound of it in 1980. It may be cleaner now but it was nasty in a hot loaded .44 mag back then. The gun was SS but after 50 rounds it was black. I had only loaded the 50 rounds so I tossed the remainder in the trash and said never again. I shoot a lot of black powder and love it but when I shoot smokeless I want it to be clean.

 

[Old Stony]

Unique is known to smoke up a case a little more than some other powders, but of all the powders out there, it is probably the most versatile. If I had to limit my powders to just one, it would probably be Unique as it can be used in handguns, shotguns, and light loads in a lot of rifle cartridges. I have shot a lot of light loads out of 45/70's using an old Lyman load calling for Unique. There are other powders that are more efficient in some areas, but Unique can be used in a wide variety of cartridges....and a little bit of smoke on the brass is no big deal.

 

[BBarn]

I believe much of Unique's reputation of being "dirty" stem from it's use in low pressure lubed cast bullet loads, an application where nearly any powder used will seem dirty. I no longer use Unique, but in the past I was surprised how clean it was in some higher pressure jacketed loads.

 

[Old 454]

I remember an old time reloaded telling me they called Unique "exploding dirt"

 

[jski]

Higher pressure means more powder. Or heavier bullets. Wouldn’t more powder just mean there’s more powder to burn and it’s more likely some won’t burn completely?

Put another way, if I have to loads with the same bullets (same weight), I’ll need more (Unique) powder to guarantee a cleaner burn?

 

[Unclenick]

I think one of the changes to Unique was a reduction in the amount of graphite applied to it. Graphite gets everywhere.

 

[Pathfinder45]

Cast lead bullets with conventional wax/grease bullet lube will always have more smoke and grime when fired in a revolver than jacketed bullets, no matter the powder. Since Unique is often used this way, it often gets blamed unfairly. Of course, you can always trade your guns for golf clubs and be done with it. Ship all your Unique to me and I will dispose of it for you. I'd use that filthy black-powder, too.
I'd be happier if I had more time just to go shooting as I'm feeling a bit deprived of trigger time these days. I need to go burn some powder and get my guns really dirty.

 

[44 AMP]

Wouldn’t more powder just mean there’s more powder to burn and it’s more likely some won’t burn completely?

Actually, its more likely the opposite. Modern smokeless powders are designed to burn UNDER PRESSURE. Unlike black powder which, essentially, detonates, smokeless powders are made to burn over a (small) duration of time, and that includes taking into account the pressure build up from gas as the powder burns. This is what is meant when the powder is called "progressive burning".

Some powders require a minimum pressure (created by a certain amount of powder) in order to cleanly burn. This is obvious in the slowest rifle powders, less so in pistol powders but there are some, such as W296 that need a certain minimum or they get erratic.

Also I would point out that smokeless powder is just that, smoke LESS, (than black powder) it is not Smoke FREE.

 

[Unclenick]

Well, technically black powder doesn't detonate in a gun. It deflagrates. I understand it can be detonated, but that it takes a very large quantity (tons) and requires high nitro dynamite as the initiator to make it happen. What's mainly different about black powder from smokeless is the ignition speed is fairly constant because it is pre-compressed when it is caked before corning, and then as each grain burns inward it does so at a constant rate and the surface area gets smaller and smaller meaning the amount of gas evolved per microsecond get smaller and smaller. That's the definition of digressive burning. The fact the grains burn at a fairly constant rate means larger grains take longer to finish burning inward, but they never evolve gas other than digressively in inverse proportion to their grain surface area.

Progressive powders make gas at an increasing rate per microsecond up to the point they reach their progressive burning limit (z1 on a vivacity plot). Stick powders do this by having a deterrent coating that stops the outside from lighting quickly, but has perforations that light fast and burn from the inside outward, causing the burning surface area to grow rather than shrink as it burns, so the rate of gas evolution keeps getting faster (the definition of progressive burning) until the expanding burning surfaces burn through to each other and to the underside of the outside deterrent coating and the core in the center of the perforation array is burning inward with diminishing surface area, at which point it has flipped over to digressive burning that wraps up the burn.

Spherical smokeless propellants are made to burn progressively despite the fact their burning surface areas are shrinking as their grains burn. This is done by soaking deterrent into the grains in an exponentially diminishing concentration. That makes the grains burn very slowly when their surface areas are still large, and then as they burn inward, the rate of combustion increases more rapidly than the burning surface area diminishes so that it more than compensates for the loss of burning area up until the deterrent gradient has been burned up. Then for the last little bit of burn, it goes over to being digressive as it finishes off its core.

 

[reynolds357]

I’ve been loading some creampuff .45 Colts using Starline’s Cowboy Special brass, .41 Specials (again Starline brass), and 38 Specials +P using Unique and haven’t really noticed it being any dirtier than other powders. I know it now says on their 1lb jar, “cleaner burning”. Not sure that means anything in particular.

What’s the consensus?

Its clean compared to Black Powder.

 

[wbbh]

Light it with lead free primers and it will burn clean.

See this for n example: https://www.thehighroad.org/index.php?threads/experience-with-lead-free-primers-clean.822136/

 

[pete2]

The black stuff wipes off with Hoppes #9 or Breakfree. For real light loads use a faster powder. A couple or 3 years back I loads 1000 9 MM with Unique and 125gr cast RN bullets, I thought they might be more accurate than plated bullets. Acuracy was the same in my Citadel pistol. I was surprised at how clean they were. Cast lubed bullets are really dirty in a .45 pistol but they were clean in the 9, higher pressure would make the powder cleaner but where did the black mess the bullet lube makes go?? I now have a DW Valkyrie pistol and I'm gonna run some 125 Cast SWC thru it and see what happens.
I'm out of Unique so I'll try a different powder this time.

 

[Nick_C_S]

Wouldn’t more powder just mean there’s more powder to burn and it’s more likely some won’t burn completely?

I know 44 AMP covered this well. But I'm compelled to word it another way:

It's counter-intuitive, but more propellant generally means a cleaner burn. More pressure = cleaner burn.

Unique is notorious for running dirty. But if you pump it up good and stout, it's as clean as any other propellant. But to be more specific, from my experience, when Unique is under-loaded, it's not so much that it runs "dirty," as it leaves unspent or partially spent powder flakes about. After some long days at the range, the stuff has been found all around inside the receiver of my 1911 for instance. It's rather comical.

I stopped using Unique. But not so much for its burn characteristics as its metering characteristics. Trying to get the powder hopper set can give fits. And the worst part is load work ups - where the charge weight accuracy is critical for getting good chronograph data. I just chose not to deal with it any longer; especially considering there's so many better propellant choices out there. And by "better choices," I mean Power Pistol .

 

[AgedWarrior]

I have used Unique for a lot of years in .357 mag, .41 mag. 44 mag and .45 Colt. Really adaptable powder, great with cast bullets in all the above cartridges. Cast lead is a little dirty in itself, so I cannot really say Unique was/is dirty in those instances. Used Universal as a sub for a while; it worked great too, but not sure it was any cleaner. Shooting cast bullets (lubed) is just messier than jacketed bullets.

Switching to semi-auto pistols, I do find Unique to be a bit dirty and tends to leave a bit of unburned powder that fouls up the works after enough rounds. I use Universal in place of Unique in semi’s and get much cleaner loads and no residual powder.

In most instances, with handguns, I can achieve the same desired ballistic performance with Universal that I did with Unique, and do it cleaner. But Unique can be used to develop some really nice reduced rifle loads...something I am not sure Universal is quite so adept at.

 

[Average Joe]

all powders are dirty, the fix is to clean when done.