Slower powder=Less leading?

[4306]

Read once that slower burning powders (Unique, Herco, etc.) are less likely than faster powders (Bullseye, 231, etc.) to cause leading at like velocities. While I know that sizing, alloy and lubrication are the real ways to avoid leading- I was wondering if anyone has seen less potential for leading with the slower powders.

[mpmarty]

The slower the powder the less damage is done to the boolit on firing and so you are less likely to have leading. This assumes you have proper boolit fit and good lube.

[RobS]

As to your powder choices...............yes in general however knowing what you are loading these powder into and what boolit you are putting on top may help give a more specific response.

The basic is slower powders don't have as much initial or starting energy as the primer sets fire vs. a quicker powder. A slower powder can "ease" a bullet into the rifling so to speak with less pressure as the birth of the boolit hits the bore.

[geargnasher]

Powder burn rate is just one factor in a forumula that needs to be balanced for best results. Generally I've had very good results from slower powders with cast, especially in rifles. When I say slow, I mean 4350 in .30-'06 and 748 in .30-30, 2400 in .357 magnum. I've also had a great deal of success with Bullesye, Clays, Red Dot, and Titegroup. It all depends on how you put it all together and what you're demanding from the load.

Some of the other important variables are alloy composition and temper, boolit fit, lube viscocity matched to the velocity/pressure, primer energy, and case volume.

Gear

[Gunsmoke4570]

I've noticed certain combinations where a slower powder will help reduce/prevent leading. A heavy for caliber boolit and/or fast twist will see the most benefit of a slower powder. In these cases the fast powder can cause the boolit to "skip" into the rifling and possibly deform the base of the boolit. In my simple way of reasoning, the slower powder steadily shoves the boolit into the barrel where the fast powder "slams" it in.

I saw this a lot when I first started loading boolits for my 40 S&W. I was using 180gr ACWW and Bullseye powder. Bullseye worked great in my 45s and 38s, so I figured it would work good in the 40 too. Wrong, shot good for about 15 rounds, then the barrel was completely leaded and wouldn't hit the broadside of a barn. Have since switched to HS6 with the same boolit and accuracy is there and the leading almost completely eliminated and I'm running at higher velocity to boot.

Just my observations, YMMV.

[Dutch4122]

I have noticed the same thing in rifle powders when developing loads for milsurp rifles. Slower burning powders, particularly in longer barrels such as the Mosin Nagant and Mauser Infantry rifles, along with a proper oversized boolit fit to the throat show a tendency to almost never lead the bore. Even with powders that are just a bit too fast in burn rate the groups will "go wild" before any leading occurs. I believe this is the point where the alloy has been "overstressed" but the gas check is still providing an effective seal at the base; as well as still "scraping" any minor leading before the boolit exits the bore.

[Larry Gibson]

Read once that slower burning powders (Unique, Herco, etc.) are less likely than faster powders (Bullseye, 231, etc.) to cause leading at like velocities. While I know that sizing, alloy and lubrication are the real ways to avoid leading- I was wondering if anyone has seen less potential for leading with the slower powders.

With standard handgun cartridges of .32S&WL to .45 Colt I have not found that to be the general case with standard loads given equal velocity. However, many times it is the case when a max load of the faster powders is used vs a medium load for the slower burning powders. As already mentioned; there are a lot of "depends".

Larry Gibson

[noylj]

As you go up in velocity, move to a slower powder. As you go down in velocity, move to a faster powder. Try to keep all loads below max pressure.
Only if you are into action pistol shooting, should you even consider Clays, TiteGroup, or other fast powders for 9mm Major or .40 Major.
I read some of their load data and shake my head. They are a lot closer to the precipice than I ever want to be. No game is worth destroying a gun or injuring myself.
Even in .45 Auto, I save the Bullseye, N310, Clays, TiteGroup, Red Dot, AA N100, Solo 1000, and other FAST powders for velocities of about 700-775 fps. If I need more velocity, I move up to Green Dot at least and generally up to AA5 or Unique.

[williamwaco]

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Read once that slower burning powders (Unique, Herco, etc.) are less likely than faster powders (Bullseye, 231, etc.) to cause leading at like velocities. While I know that sizing, alloy and lubrication are the real ways to avoid leading- I was wondering if anyone has seen less potential for leading with the slower powders.

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I have used all these powders for many years in .38 Spec, .357 mag, 9mm, 38 super, 41 mag, 44 mag and 45 ACP with cast bullets at velocities from 600 to 1600 fps.

If you are having leading problems with any of these powders at any velocity they are capable of achieving in any of these cartridges, You problem is not with the powder, Your problem is either a lube or a sizing problem.

I am NOT disputing your assertion that slower powders are more gentle on the bullet than faster powders. I am saying that for the powders you mentioned, in handgun cartridges, there is no noticeable difference in leading. NONE of these loads should produce leading problems with good lubes and properly sized bullets with any load safe for the cartridge.

[44man]

I would bet that 90% of leading has it's start with a boolit skidding past the base, slump and general boolit destruction.
Next is a poor lube and no matter what everyone says, my worst case was with LLA. Even hard lube has not caused any leading to speak of for me but each different lube has changed accuracy. That might be related to bore conditions left between shots, carbon buildup, etc.
That leaves lead hardness and fast powder does ruin a soft boolit faster. Just how much destruction you get depends on a lot of things.
Assume everything is a perfect fit, will that stop leading? No, not if the boolit skids to open gas channels and the easiest way to halt too much skid is to make the boolit harder and tougher.
You can shoot mighty soft boolits without any leading once some kind of balance is reached but in my experience, accuracy will leave the fastest. Just fiddling with the alloy can turn a 6" group into 1" without changing anything else with no difference in leading if you cured the leading with the softer boolit.
If you get leading you have no accuracy, fooling with the charge, powder or lube just gets you nowhere faster and even if you cut the leading you still have poor accuracy.
While it is true a slower powder is easier on a boolit I always felt the search was backwards and accuracy should be looked for first. It seems an accurate load will have far less leading and mostly none at all. Sure, in the search you might have leading but as the things are changed for better and better accuracy you might find you can shoot cast for years without ever cleaning the bore. If that means alloy changes, so be it. To stick to a ball of putty will not get you far.
Find what your gun likes, maybe some tin or tin and antimony or plain old WW's. Maybe water dropped.