Negative effect of lube on powder burn... question.

[saxguy]

For many years (until 1997) I cast and sized my own boolits, the latter part being tumble lubed mostly. Seeing as I am now getting back into shooting pistol, I once again look forward to pouring the silver stream. This time however, instead of tumble lubing (ugh, what was I thinking!) or relying on store bought stick lube, I will be attempting to make my own. Questions come to mind however, such as quality control. One question in particular, if the components of the home brew lube contain elements that may separate given the right conditions, this surely must effect the burn rate of the propellant.

Example, if one of the components of the lube is a grease or oil, if the loaded rounds are subject to heat (our UV is vicious in NZ) can the oil leach from the lube and be taken up by the propellant?

Are some lubes more prone to this than others even?

I have pulled a few tumbled lubed loads that have sat in the sun, and did note a bit of ‘stuck’ propellant on some of the bases. I didn’t do a burn test on the adhered propellant but im sure it must have some effect. I know that powder can be rendered useless by oil/diesel etc, so im presuming that similar compounds leaching from a lube may to some degree have this effect.

Just wondered if anyone has done any research in this area.

Thanks.

[randyrat]

More than one has asked the question: Why do we use beeswax?
One of the reasons is beeswax binds up oils and greases, weather they are petro or Veg based and beeswax doesn't like to give it up, in fact, I don't know how to separate greases and oils from beeswax. I'm not sure if is even possible.

If you overload your beeswax with too much Oils or Greases then maybe you may have some leaching out, but that is part of testing when making lubes.
If you try to mix Veg oils, greases and petro oils, greases without a binder then you may run into a problem also.

I've never had a leaching problem with my TAC 1. One test was to set a flat sheet of TAC1 in the HOT garage and sprinkle gun powder on it for a week ( July or Aug) then ignite it and compare. I also loaded some and leave them in my vehicle for a few weeks in a black plastic bag..........never a problem...... It's as scientific as I get...

Look at the molecular structure of beeswax there's your answer.....I would look but i wouldn't know what the heck I'm looking at

[David2011]

Just a seat-of-the-pants thought here. The fit between the boolit and the brass is pretty darned snug. Not impermeable, I would think, but a very close fit. It seems like moderately high temperatures would not be an issue. By moderately high, I would define that as a variable depending on the lube of temperatures that would make the lube very soft, even softer than you would want to heat it for lube sizing but not liquid. I just don't see lube migrating into the powder at that temperature. Once it's hot enough to become liquid I can see that it MIGHT migrate to the powder. Some brass is thick enough that you can see where the base of the loaded boolit bulges the brass- .38 Special and .45 ACP military brass, for example. It's hard for me to imagine the lube getting into the powder in a cartridge like that due to the very tight fit between boolit and brass. OTOH, if the brass barely grips the boolit, it seems like migration would be much more likely if hot enough or the lube to become liquid.

Having lived in hot climates my entire life, my concern has been more with the storage of sized and lubed bare boolits than loaded ones. My new reloading room is heavily insulated and the desert nights are always cool which keeps the room from getting very warm. When the highs are well over 100 degrees the boolits aren't exposed to significant warmth even if the air conditioner hasn't been run for a few days. I plan on trying some lubes that don't require heat now that storage isn't an issue. Actually, TAC 1 has become very attractive even if the previous post hadn't been Randy's. Most of my shooting is USPSA matches so low smoke is important.

David

[lylejb]

While I too started out making homebrew lube, you might look at randyrat's TAC1 or White label lubes at lsstuff.com

Both are members here, and both are priced so low that it's hard to buy ingredients for less than they charge.

[randyrat]

Good point David..Another good reason to wipe the base if your Dip or Pan lubing....
While beeswax has a gradual melt stage (solid to soft to liquid) unlike Paraffin or petro based lubes which has a solid to a liquid "quick" stage