I loaded some low-mid range target loads in 357 with true blue. It’s leaving just a tiny bit of unburnt powder. Im pretty sure if i went up .2 or .3 it would burn cleaner, but I’m just curious, what is the downside of having a very slight amount of incomplete burn?
Unburnt powder question
- Thread starter bcook4321
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LiveLife
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Inefficient powder burn ---> More fouling and inconsistent chamber pressure build ---> Inconsistent max chamber pressures ---> Inconsistent muzzle velocities ---> Larger group size
tightgroup tiger
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Some powders are notorious for leaving unburnt powder behind, like 2400.
Most all ammo does this to some extent.
Just walk out on the floor at an indoor shooting range sometime. Just be carful, it's slippery as hell. The unburnt powder from all the factory loads is laying out there turning the floor to a light grey color. They are usually painted white so they can see the color start to change and know it's time to clean the floor again.
This happens over a period of months.
So depending how much unburnt powder your seeing, it may be normal. Especially with really fine powders like True Blue. It's probably par for the course.
Raising the amount of powder may help but you will never get rid of it completely. And just because you don't see any in your gun doesn't mean it isn't still going out the barrel on a regular basis. If it weren't, it wouldn't be all over the floor at the indoor ranges.
If the ammo factories can't make it burn 100% clean with their resources, we don't stand a chance of doing it either.
If your just seeing a few flakes now and then, don't worry about it. If you are seeing more than that, you maybe should switch powders.
Most all ammo does this to some extent.
Just walk out on the floor at an indoor shooting range sometime. Just be carful, it's slippery as hell. The unburnt powder from all the factory loads is laying out there turning the floor to a light grey color. They are usually painted white so they can see the color start to change and know it's time to clean the floor again.
This happens over a period of months.
So depending how much unburnt powder your seeing, it may be normal. Especially with really fine powders like True Blue. It's probably par for the course.
Raising the amount of powder may help but you will never get rid of it completely. And just because you don't see any in your gun doesn't mean it isn't still going out the barrel on a regular basis. If it weren't, it wouldn't be all over the floor at the indoor ranges.
If the ammo factories can't make it burn 100% clean with their resources, we don't stand a chance of doing it either.
If your just seeing a few flakes now and then, don't worry about it. If you are seeing more than that, you maybe should switch powders.
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twarr1
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black mamba
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In worst case scenarios the unburnt kernels can wedge under the crane or ejector star and bind up a DA revolver.
fxvr5
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What data do you have to support this?
When tested, the evidence shows there is no correlation between between consistent velocity and group size in the typical handgun at typical handgun velocities:
https://americanhandgunner.com/handguns/exclusive-consistent-velocity-accuracy/
Moderate unburned powder kernels in the barrel that simply move out each shot -- no big deal.
LOTSA unburned in a closed/unmaintained environment......
(Note the range appears to have a slatted floor above a concrete base where powder fell into the grooves/below the surface. Supposedly in Brazil)
LOTSA unburned in a closed/unmaintained environment......
(Note the range appears to have a slatted floor above a concrete base where powder fell into the grooves/below the surface. Supposedly in Brazil)
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243winxb
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Residue from burnt powder may get between the cylinder & ejector star & bind up the cylinder when turning. In a lever action rifle, residue will fall into the action.
On revolvers, eject with muzzle up.
The firearm will let you know if there is a problem.
AJC1
Member
I move up the burning rate chart until I reach a point it's no longer noticeable. 4227 gives me an excessive amount in any pistol I've shot. So join me and a few others testing our way through the burn rate chart.
tightgroup tiger
Member
I can easily believe that, knowing first hand how much powder goes out a barrel that is unburnt. Most people think all powder is consumed when the cartridge is fired and have no clue how much actually isn't.
It's hard to imagine how it can happen but it does, each and every time a gun is fired. The slippery stuff on the floors is usually ball powder that is harder to ignite and is like very small ball bearings under your shoes.
LiveLife
Member
At least that's my theory based on various load developments I have conducted over the decades as I progressed from published start charges and worked up towards max charges. In general, unless I am using faster burning powders, group size trend improved as powder charges increased. Depending on powder, sometimes smallest groups were obtained around high range load data and sometimes around near max/max load data. With faster burning powders, accuracy was obtained even at start to low powder charges and with even faster powders like Bullseye, even below published start charges.
OP is using True Blue, relatively "slower" burning powder and based on my experience, I found "slower" burning powders than Unique/Universal tended to achieve optimal accuracy towards max charges. With low to mid range load data, even with moderately fast burning powders like W231/HP-38, I found unburnt powder granule flash back towards me and when powder charge was increased, unburnt granule stopped and group size decreased.
American Handgunner article used 6.5 gr of Power Pistol with 115 gr Zero JHP at 1.115" OAL where Speer load data lists 6.7 gr as max charge for GDHP loaded to 1.125" OAL so essentially near max load was tested -https://reloadingdata.speer.com/downloads/speer/reloading-pdfs/handgun/9mm_Luger__115_rev1.pdf
And while 5.3 gr of True Blue was used with 124 gr Nosler JHP at 1.110" OAL, Ramshot load data lists 5.5 gr as max charge for Hornady XTP loaded to 1.060" OAL so essentially near max load was also tested - https://www.ramshot.com/wp-content/uploads/2020/08/WesternPowdersHandloadingGuide8.0_WEB.pdf
But OP is not using near max load data rather low to mid range load data.
I do agree with the American Handgunner article findings that at near max load data range, variation in velocity may not equate to group size. Perhaps I may do a myth busting thread on start-to-low load data vs high-to-near max load data accuracy difference.
Claus
Member
Lots of good information here. I also try to load low-mid range target loads to make them a little more comfortable to shoot. But yeah, they’re pretty dirty and leave a good amount of powder unburnt. I’m still somewhat a beginner and use primarily Bullseye power.
So what would be some powders that would work for this? That is, cleaner burns with lighter loads.
So what would be some powders that would work for this? That is, cleaner burns with lighter loads.
AJC1
Member
As said fast powders like bullseye will burn completely. I use a lot of tightgroup for exactly the same reason. The higher the pressure the better the slower powders burn more completely. It's easy to test in 38 vs 357. The slowest powder listed in 38 will most likely not burn completely, and will most likely be clean in 357.
YellowcatDaddy
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I’m really a novice, so my question may sound really dumb. So if slow burning powders burn more completely at higher pressures, can you create that higher pressure by putting a heavier crimp on .38/.357? And the increasing the charge by .2-.4. Will get a better burn?? Seems counter intuitive when your having trouble with unburned powder to begin with.
AJC1
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If you increase the crimp you increase inital pressure. If you increase charge you increase pressure. At no point does the pressure of 38 ever come close to 357.
Yes ^^^^^ this is a small part of the big picture.
You want to increase your short start pressure, doing this will create a more efficient powder burn. Things like:
lite VS heavy crimp
case neck tension
bullet design & the amount of the bullets body is actually in the case
How much free bore the bullet has in the cylinders
All these things can and will affect efficient the 357mag reload will burn it's powder charge.
Yes, in general more powder/pressure helps a clean burn, assuming there is room pressure wise to do so. Sometimes switching powders for an application is the answer.
What bullet/powder charge? I am guessing you have room to bump it up a little. True Blue is good stuff, but like another very small grain round ball powder (AA #2), it can leave granules if the pressure is too low.
What bullet/powder charge? I am guessing you have room to bump it up a little. True Blue is good stuff, but like another very small grain round ball powder (AA #2), it can leave granules if the pressure is too low.
Thank you for posting this, it gives us reloader's some insight on what the raw numbers actually are and how much they affect group sizes.
What your link doesn't take into account is something every 1st year target shooter is taught. Namely "dwell time".
A shooter is not a mechanical rest and the dwell time of the bullet in the bbl of the firearm affects group size more then a +/- 100fps load deviation ever could in a mechanical rest/ransom rest.
AAHHHH, They said no math!!!!!!!!!!
Great you have your 2" group @ 50yds using the op's true blue target load in his revolver staged in a ransom rest. The difference in dwell time/recoil between the inconsistent burning loads only has to cause a 1/100th" change in muzzle flip/where the end of the bbl is pointing to turn that 2" group into a 5" group @ 50yds with a 6" bbl'd 357.
This is why Live Life is absolutely correct when he says "consistency ='s accuracy".
Same felt recoil, same grip, yada-yada-yada VS POP, bang, snap
Carl N. Brown
Member
"Most people think all powder is consumed when the cartridge is fired and have no clue how much actually isn't."
I reload pistol ammo with Unique and have noticed unburned flakes.
I have heard of testing efficiency of black powder by shooting muzzleloaders over snow and checking the surface of the snow for unburned powder.
I have read estimates that the unburned amount runs about five percent of the total charge with a lot of variance which confirms my suspicion that volumetric or dipper charges are good enough for range work.
BTW: Watching that video confirms my preference to shoot outdoors.
"Note the range appears to have a slatted floor where powder fell into the gooves/below the surface."
On a hi-res laptop the fire appears to follow the slats in the floor. As tho' sweeping the floor may have resulting in the flats packed with unburnt powder..
I reload pistol ammo with Unique and have noticed unburned flakes.
I have heard of testing efficiency of black powder by shooting muzzleloaders over snow and checking the surface of the snow for unburned powder.
I have read estimates that the unburned amount runs about five percent of the total charge with a lot of variance which confirms my suspicion that volumetric or dipper charges are good enough for range work.
BTW: Watching that video confirms my preference to shoot outdoors.
"Note the range appears to have a slatted floor where powder fell into the gooves/below the surface."
On a hi-res laptop the fire appears to follow the slats in the floor. As tho' sweeping the floor may have resulting in the flats packed with unburnt powder..
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The indoor club I used to be a member of, we'd clean the floor daily with a 48" dust mop. Took 2 or 3 minutes, no big deal. The air filters in the air handlers was what took time & was messy. It was impressive how much junk they could hold in 1 weeks time. We'd clean them weakly and with heavy use in the winter months (ne ohio) it changed to a twice a week.
fxvr5
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?
I don't know if I get your point exactly, but differences in velocity from one round to another affects the Ransom Rest movement the same way it would affect a person. Faster/slower speed (dwell time) = more/less recoil = more/less Ransom Rest or hand/arm movement.
Ranger99
Member
I'm so happy to see somebody else
that realizes this ^ ^ ^ ^
I guess that makes two of us
To me, "unburned " powder, or
powder residue is a non issue. I have
many cleaning patches, and at least
one of my cleaning rods can be used
over and over
Accuracy should always be the first
and foremost goal in loading.
Anything else is pretty much superfluous
and can be dealt with if need be
LiveLife
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