Sooty cases and or scorched cases . What causes each ?

[Metal God]

I've been loading pistol for about a year now and always thought a sooty case meant low start pressure not sealing the chamber . I how ever just read that a sooty case means the powder is just a dirty burning powder . Is it a little of both or just dirty powder ?

That leads me to the next question . What about scorched cases , what does a scorched case indicate ? I only have one powder that does not scorch my 9mm cases and that's Titegroup and only one that does not scorch my 45acp cases and that's HS-6 with 230gr lead RN . I have not tried Titegroup in 45 yet . CFE pistol scorched my 45acp cases all the way down to the extractor groove . Before you start saying try this or that powder . You should know my local powder selection is quite poor . NO bullseye , W-231 or most of all the good stuff so keep that in mind .

When I see sooty or scorched cases I say to my self not a good powder for the application . Is that a correct way of looking at it ?

Two examples of powders that gave me sooty scorched cases . Auto comp and 125gr plated bullets in 9mm , Longshot and 200gr plated bullets in 45acp . I have just put those powders away along with CFE pistol because of it .

I thought I was starting to get a good understanding as to the relation between burn rate and bullet weight for caliber but now I'm not so sure . Thought I'd ask this question one last time to be sure I'm not giving up on some powders prematurely .

 

[Walkalong]

What causes each ?

Generally low pressure.

 

[eldon519]

I also find it happens with slow powder too, even at full pressure. I haven't checked in Quickload but my suspicion is that the slower burn rate hasn't built enough pressure to fully seal by the time the bullet leaves the case. I see this a lot in H110 revolver loads.

 

[Blue68f100]

If the soot is on the outside of the case it's low pressure. For light load fist powder is best since it builds pressure at a lot faster rate. As for low powders it's a mixed blessing. When I started shooting 357mag with W296 the first book I had said to load as stated, not reducing the charge any. Then the next time it got updated they said reduce charge 3% max. Some powder just burn dirty, you just live with it. Or change powders to one that burn cleaners.

 

[Captcurt]

Slow powders like H110, 2400 and AA9 indeed a hard crimp for consistant ignition. I noticed that some cases sooted and checked them out. They were not trimmed to the same lenght which changed the amount of crimp that they were getting. After trimming all of them to the same lengh things got a lot better. Different brands of brass can do the same thing because of different wall thickness or hardness.

 

[Jlr2267]

What was your Autocomp load? I have used it with 124gr jacketed and plated bullets, and did not notice any unusual scorching or soot.

 

[ZWCoffindaffer]

I was curious about this too, but never looked into it. I've never seen any case damage when reloading, so I just dont pay it much attention anymore.

On a side note...

I have not tried Titegroup in 45 yet

I know every gun is different, but my groups at 7 yards with my XDs went to a third of the size when I changed to titegroup from HS-6(looks like we have about the same powder selections) Longshot shot TERRIBLE in 45. Its too slow. 45 doesnt make enough pressure. Anyways, if you havent tried Titegroup in the 45, give it a shot. Just be careful, it doesnt take much and its hard to see an overcharge in the .45 case with that powder.

 

[243winxb]

Accuracy & function are number 1

Using the fastest powder burn rate data available for a cartridge may help. But may not get the highest velocity. Having said this, it would seem Bullseye powder would be perfect, not so. My target load ,low pressure, still leaves brass looking scorched in 45 acp. All i ask for is accuracy and good function. It does that.

 

[Metal God]

Going back and looking at my notes . It appears I tested two different bullets in 9mm with Autocomp

Hornady 125gr HAP
Auto comp - start at 4.2 ended 5.0 / with 4.6 @ 1050fps avg and 4.9 @1095fps avg , being the most accurate . Both had sub 10fps SD 5 shot groups
Case - Fed , all were trimmed
COAL 1.060
Fed #100 primers

Berry's 124gr platted RN

Autocomp - start 4.3 end 5.0 . I never shot the 4.9 or 5.0 charges because the firearm was getting a little snappy and 4.7 and 4.8 shot quite well
Fed- cases all trimmed
COAL 1.125
Fed # 100 primers

My load I use is 4.8gr @ 1052fps ES 27 SD 14 / 5 shots

FWIW when I do load development I weigh each charge and use check weights when I change the charge .

I should also add these were the first pistol loads I had ever loaded so although not real snappy at the higher end . I was starting to feel a difference and since I already past some accurate loads . I felt no reason to go higher .

 

[Jlr2267]

Going back and looking at my notes . It appears I tested two different bullets in 9mm with Autocomp

Hornady 125gr HAP
Auto comp - start at 4.2 ended 5.0 / with 4.6 @ 1050fps avg and 4.9 @1095fps avg , being the most accurate . Both had sub 10fps SD 5 shot groups
Case - Fed , all were trimmed
COAL 1.060
Fed #100 primers

Berry's 124gr platted RN

Autocomp - start 4.3 end 5.0 . I never shot the 4.9 or 5.0 charges because the firearm was getting a little snappy and 4.7 and 4.8 shot quite well
Fed- cases all trimmed
COAL 1.125
Fed # 100 primers

My load I use is 4.8gr @ 1052fps ES 27 SD 14 / 5 shots

FWIW when I do load development I weigh each charge and use check weights when I change the charge .

I should also add these were the first pistol loads I had ever loaded so although not real snappy at the higher end . I was starting to feel a difference and since I already past some accurate loads . I felt no reason to go higher .

Interesting...my notes show that I ended up with 5.3gr for the 124gr Berry's plated, 5.0gr with a 124gr XTP.

My loads are slightly warmer, and maybe that is the difference. If the lighter load is what your pistol likes, that's where you should stay. A little soot is a small price to pay for accuracy.

 

[Metal God]

With the more experience I now have loading pistol ( been loading rifle for years ) . Maybe I'll go back and try a few closer to max charge . Autocomp and Longshot were the first two pistol powders I could find locally . Since then Titegroup , HS-6 and WSF all have become available and work much better for my applications .

Going to keep the slower stuff around because I do plan on owning firearms in 357sig and maybe 40 S&W . My research says Some of the powders I have but don't use will do quite well in other calibers I plan to own some day . I'd own them all by now but I'm in CA and we are very limited on the brands and models we can buy new here . No Rugers , S&W , very limited glocks and XD . There's not much out there that either fits my hand or in my price range . Very disappointing really .

 

[Average Joe]

Low pressure or no crimp.

 

[Metal God]

Yep I'm going to stick with my low pressure understanding of the issue rather then some powders are just dirty and that's how you know .

As for crimp , when I first started I had many questions about crimp and what constitutes a light , mid or heavy crimp . I posted this picture and asked which crimp was good and which would be to much . I'll ask here the same thing ? Please describe what bullet has to little or to much and why . They all passed the plunk test .

FWIW these are 200gr Hornady JHP xtp

 

[243winxb]

Crimp and neck tension 45 acp

As for crimp

When a taper crimp marks a jacketed bullet in 45 acp, your doing something wrong or you have a Lee seating die that is said to taper then roll crimp. All 3 ,to much crimp. I hope you have the answer by now?? https://thefiringline.com/forums/showpost.php?p=6146548&postcount=18 Bullet set back is about neck tension. IMO. Not crimp. Different brands of brass produce 45 to over 100 pounds of bullet pull.

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2nd , how much crimp on a bullet that does not have a crimp grove ? I tested 5 different crimp strengths from none just that slight swage to heavy crimp that indented the bullet about .011 . The dents in the bullets were ( .0015 , .003 , .006 . 009 .011 ) . All 5 past the plunk test and measured the same depth from head to top of barrel area .

230gr RN lead bullets http://thefiringline.com/forums/showthread.php?t=566094&highlight=lee+die+45+acp For a lead bullet, .011" is over kill. Note that Lee dies are being used.

 

[Metal God]

I since have tested that set back issue in My XD45 compact . At the time I had only been using my 1911 . I do not get the bullet set back with the XD but still do in the 1911 . I conclude that there is something happening in the 1911 that does not happen in the XD . I stopped loading the xtp bullets so the 1911 xtp set back problem has not been resolved .

Note : I have since found that case wall thickness has a big influence on how much swage I get using the FCD . Thin walled cases like PPU , Aguila . R.P. have very little swaging when loading the lead bullets . While Fed , Win , Speer swage the bullet down more .

 

[Gearhead Jim]

http://imagizer.imageshack.us/v2/800x600q90/540/Bsfz1W.jpg

Metal God-
I'm loading plated bullets (X-Treme 100 gr FP) in .380, haven't loaded plated in anything else.
I use just enough "crimp" to eliminate the belling on the case mouth, no more.
My magnifying glass and my micrometer both show the case mouth on a loaded round is same diameter as further back. And although my Glock 42 is no sniper rifle, my reloads shoot as accurately as any factory ammo I've tried.

But...
If I pull the bullet from one of my reloaded rounds, it will have a similar line as your photo.
Without having some pulled bullets side by side, the comparison won't be exact, but certainly similar.
If I use sandpaper on the area of the "ring", I can sand until the ring disappears and it's all smooth copper, but I'm still not through the plating.
My suspicion is that there is enough spring-back to the brass case that it may be impossible to avoid getting the ring unless you are willing to accept loaded rounds that are still slightly belled. That was my experience when I was adjusting the taper crimp die down, gradually, to eliminate my belling and no more.

 

[LiveLife]

As for crimp, when I first started I had many questions about crimp and what constitutes a light, mid or heavy crimp. I posted this picture and asked which crimp was good and which would be to much. I'll ask here the same thing? Please describe what bullet has to little or to much and why.

For me, since case wall averages around .011" in thickness, light taper crimp is adding .022" to the diameter of the bullet and heavier crimp is adding .020" to the diameter of the bullet.

Example:

.451" + .011" + .011" = .473" light taper crimp

.451" + .010" + .010" = .471" heavier taper crimp

I have since found that case wall thickness has a big influence on how much swage I get using the FCD

bullet at crimp after pulling .450
bullet at base after pulling .451

I would pull some rounds and measure the bullet diameter, especially with some of the thicker walled cases. Your other thread showed .452" diameter bullet post sized down to .450" - .451" and this will significantly reduce neck tension and increase bullet setback as brass spring back will pull away from smaller diameter bullet. Was this with thinner or thicker walled cases?

If adjusting the FCD won't stop post sizing the bullet, I would set the FCD aside and use the combo seater/taper crimp die. While I use Lee dies, I do not use FCD.

 

[rsrocket1]

MetalGod,
I do know what you are talking abut when it comes to the difference between sooty cases and scorched cases. When I first started loading, I would go overboard with starting low and would do things like shoot a 230g 45ACP bullet with 4.0g Unique. I got blowback in the face and sooty cases. I still can get sooty cases but more often than not, now that I am experimenting with so many different powders, I also experience scorched cases.

Scorched cases usually don't show the scorching all the way around or if so, not the entire length of the case. The same goes for sooty cases but I have yet to see a case showing scorching the entire length.

I need to take better notes, but if my memory serves me, scorching tended to occur with powders having higher concentrations of Nitroglycerin (double based powders). While I have had sooty cases with low charges of Unique, Red Dot and Clays (very low NG content), they were not scorched. I've had some pretty nasty looking scorching with Titegroup even though the loads were within a few tenths of max, there was scorching near the case rim that went down about 1/4 of the way down the case.

A couple hours in the vibratory tumbler with crushed walnut shells cleans off both the soot and scorching.

 

[bbqreloader]

Thats what I like about THR, someone is always in the same boat, sotra, as you. I am having the same problem with 45 185gr xtreme. Loaded up test rounds of #5 and was getting sprayed by powder. Started low end and was working up, but now I know to work up a little more to see if that fixes the issue, still well below max.