Fired Cases Question

[jimmyj]

Hi:
When the fired cases from a revolver has smut on them, what is the cause ?
I am thinking crimp too light or bullet lub ?

Thanks.
Jimmy

 

[k22fan]

Obviously the pressure is to low to press the case walls tight enough against the chamber to seal off the gas. When that's happening there can not be any concern about bursting the cylinder so a little more powder might be the answer. More crimp might help a tiny bit but a heavy crimp does more to help slow powder magnum changes burn.

 

[rockquarry]

Not sure how to respond as I don't know that I've ever encountered what you mention. Perhaps a photo would help.

I use only cast bullets in handguns and don't recall ever seeing but the slightest residue, if any, on cases fired in revolvers or automatics. Regardless of the type crimp used, I crimp everything as lightly as possible.

I'm somewhat skeptical of the "dirty powder syndrome" unless an unsuitable powder and/or the wrong charge weight is used in a load. Perhaps that will cause dirty cases, but I don't know that for sure.

Bullet lube often makes smoke upon firing and may leave residue on the outside of the cylinder and cylinder face, but it has minimal effect on brass. A soft lube is mostly consumed anyway and a portion of hard lube often stays on the bullet to the target.

 

[arjay]

I agree with k22fan.Too light of a charge

 

[fredj338]

Lubed lead bullets are always going to be dirtier shooting. The carbon mixes with the lube & you get stuff all over the gun. If you are getting large scorched sections of brass down the outsize, probably very low pressure.

 

[hdwhit]

I concur with k22fan and arjay; too light a charge leading to insufficient pressure to expand the case walls against the chamber.

A big isn't necessary. A tiny increase in charge may be all that's needed to get the pressure into an appropriate range.

 

[jimmyj]

.45 Auto Rim cases with a 200 grain cast LSWC and 4.5 grains Bullseye is what I am using

 

[Wise_A]

It's only a problem if you think it's a problem.

 

[Nevada Ed]

I did a lot of X-lite 9mm loads to see what powders would still
work the pistol and be on the clean side, c/o the brass cases.

Any powder can be loaded too low for its burn rate and leave a
dirty case, even if it might eject and push a bullet out of the barrel.

However you do want a "Safe working" load that will not have a "Squib"
incase a powder throw is on the light side, which can happen.

I had a 3" Kahr 9mm that had a dirty starting load but just .1 more powder
added 30fps and the case was on the cleaner side, that I could live with.

In my 9mm pistol loads, CFE pistol has given me light loads with good accuracy.
W231 has also worked but I do not load 45 cal. so you will have to
get more info on what powders might work for you but.............
you might add .2 grains to your load and see if things improve
in accuracy and cleaner cases. Just a normal crimp should work.

Good shooting.

 

[alwslate]

If by "smut" you mean the residue left on the cases from burning powder,
this is normal. Bullseye smokes up cases a little more than some other
powders. Wiping fired cases with paper towels is just part of handloading
and is no big deal.

 

[jake1945]

My light loads in 45 colt smudge the brass pretty good. So yeah, load is too light.

 

[H Richard]

My wimpy 2.7 gr Bullseye or 3.0 231 in a 38 revolver do give a little residue on the case, but the accuracy is worth it, and I clean the gun every time anyway, so what?

 

[10mm_Shooter]

..as everyone has said, a low pressure load will leave "blow by" smut/carbon pick you term. It simply means the pressure did not expand the brass enough to completely seal the chamber, some blow by escaped rearward and dirtied your brass. I have low pressure loads with Green Dot and Red Dot, that will do that to my .38 brass and my .44 brass. Just yesterday I tried 6.0 grs of Green Dot, chornos at 815 fps, it has blow by, you get back to about 7.0 grs and that's just enough to eliminate the blow by. ….its a non-issue, if it bothers you, adjust your charge or change powders to generate more pressure(with in limits of course).

 

[ArchAngelCD]

Jimmy, you are almost at the max charge of Bullseye so it's not the powder. Bullseye isn't known for being the cleanest powder but I have a feeling the bullet lube might be causing your soot. Have you tried a coated cast bullet? How about a plated bullet? If you did does the case look the same? If not it's a good indication the lube is the problem. Hey, just tumble them a little longer lol.

 

[LoboGunLeather]

I agree that the residue on cartridge case exteriors is most likely caused by pressures insufficient to completely swell the brass against chamber walls.

Only other comment I can offer is about manufacturing tolerances. Every machined part will vary to some degree, primarily due to tool wear during the manufacturing cycle. Manufacturers must allow for a range of tolerances, with chambers cut with a new cutting tool (chambering reamer) being at or near the maximum acceptable dimensions, and those cut with a worn tool becoming somewhat smaller and approaching minimum acceptable dimensions until the tool has worn to a point that it can no longer produce finished parts within the range of tolerances.

It is possible that the OP's revolver has chambers finished closer to the maximum acceptable dimensions which, coupled with relatively low-pressure ammunition, would be more likely to result in powder residue being deposited on case exteriors.

Manufacturing tolerances also appear in ammunition components. Some lots of cartridge cases can be expected to have thicker, thus stronger, case walls and/or brass that may be more or less ductile (subject to expansion under pressure).

None of these conditions (or combinations of tolerance ranges) are proof of any unsafe conditions or other concerns. Just the nature of the business in manufacturing millions of individual parts and pieces, even using the best tooling and machinery.

 

[Zero Down]

All my 45 ACP loads do that.
I only need 674 FPS to make power factor for IDPA matches, Steel Challenge and outlaw matches are loaded considerably lower.
Nothing I have ever worried about, my S&W 625 is nicknamed "Old Smokey".
Larry A.

 

[S&WIowegan]

I agree that the light charge causes pressure low enough to not expand the brass enough to seal the gas/smoke blow-by.

It might be of interest to some of you that this can happen with factory fresh ammo. I have an S&W 929 which I use in IPSC and steel shooting. I read reports that this revo seemed to prefer heavier bullets so I bought a case of Federal 147 gr JTC ammo. This ammo doesn't seal the revo chambers and the brass is black with soot.

Pistol Caliber Carbines have recently become popular for action shooting with 9mm being the predominant caliber. Factory Federal 147s come out with black cases. Recently Speer issued a warning to NOT use their 9mm 147 gr ammo in carbines due to potential for bullets to stick in the barrel causing damage to the barrel and danger to the shooter.

I have a friend here who just bought an AR9 style carbine. During his first firing, the first bullet did not exit the barrel and several follow-up shots stuck behind it and destroyed the barrel. The manufacturer allowed my friend to purchase a new barrel. Ammo was handloads.

 

[gboling]

I have difficulty accepting the light load theory. My full house 44 magnums loaded with 2400 are the dirtiest cases I ever have. I have never contemplated a cause, I just tumble them and go again.

 

[Forrest r]

Bump the load up to 5.0gr of bullseye and re-test.

FWIW:
That 4.5gr load of bullseye pushing that 200gr lead swc is no where near max anything. It's actually pretty anemic at best. It's so low companies don't even both printing the pressure of that load.

Lyman 49th 452460 200gr lswc
bullseye 4.7gr 775fps -------
reddot 5.2gr 845 -------
ww231 5.5gr 936 14,100cup

The only max load listed in that 49th manual that even bothered to print the pressure of that max load is that ww231 load. Reddot is faster burning than bullseye and lyman has no problem printing use 5.2gr of it.

The 45ar case has more case capacity than the 45acp case.
The 45ar case is just as strong if not stronger than the 45acp case.
Both cartridges are fired in the same firearms.

The 45 auto rim is another 1 of those cartridges that should be updated (along with the 44spl). A company comes out with that cartridge in 1920 and puts a soft lead bullet in it that has a hollow base to be used in the surplus 1917 revolvers that were flooding the market. The cylinders and bbl diameters varied so much on those 1917's they went with a soft bh lead bullet. They didn't want the skirts to blow off those soft lead bullets so they made the 45ar low pressure. It's been that way ever since.

Mold makers have sold hb molds for decades to home casters. A early cramer hb swc mold that casts a .454" bullet for the 45ar or can be sized down to .452" for the 45acp.

That cramer bullet is the 1 on the bottom left. Other hb cast bullets I've cast shot in the 45cal's.

You ought to get some 185gr hornady xtp hp's and push them with 6.2gr of bullseye in those 45ar cases. Those loads are flat shooting, hit hard and there isn't a lot of recoil.

 

[jwk]

Low pressure. Might be minimal safe charge but might be inadequate crimp even with a safe load. Are you roll crimping or taper crimping?