Turns out there's a lot to know about bullet lube. Here's an article on grease flow and viscosity (thixotropy) with a couple of copyrighted electron microscope images of grease thickeners showing the matrices they form. Sodium soap strands (Ivory) are about 100 times larger than lithium soap strands, by way of reference to the lithium soap image int the article
http://www.intechopen.com/books/tri...low-in-lubrication-systems-and-friction-nodes
I'll try to explain my previous post a little more in-depth.
This soap matrix is the "last stand" of the lube. The oils (necessarily a straight-chain paraffin oil for the most part to plasticize the waxes at room temperature and below without causing excess slickness due to branched strands separating and flowing too easily, with castor bean oil added in small percentage to bolster the film strength) are what lets the lube flow in the first stages of the firing event, when the bullet is moving slow and swaging into the throat. If the lube remained a thick goop for long, it couldn't flow as fast as the bullet and would ball up and be left behind in the throat as a giant smear (yes, I've figured out ways to make lubes that didn't melt or thin out and that's what happened). So we need to use what we came to call "middle modifiers" to help the lube thin out more quickly. Paraffin wax has a low melt point and thins quickly under pressure. Beeswax has monoesters that do the same thing, there are many other things that do as well. Finally, at high speed we want the lube to thin out even more to keep up with the bullet speed, but not too much or it will lose the ability to seal (think lubing a bullet with diesel fuel vs. heavy engine oil). Toward the end of a rifle barrel, the speed and friction heat is very high, but pressure on the bullet base is dropping off, so lube blowout and loss of obturation is likely as the lube thins but the bullet relaxes in the bore. Sort of a catch-22. Ever hear of "running out of lube" being the explanation for leading toward the muzzle end of a rifle? Losing the lube seal at the relax point of the bullet and having a lube that just goes all watery by then is often the cause. The fix? One good one is a metal soap that ideally never melts in the barrel, but holds the fully-molten wax and oil slurry together like a sponge full of water until the bullet finally exits the muzzle. Metal soaps are actually a micro-sponge that are highly polarized. Micro-crystalline wax has a sponge matrix similar to the soap and assists in holding oil at "room temperature", but of course this breaks down as the wax melts. We want this. The different waxes, oils, and soaps make a lube that will stay in the grooves during the lubing, loading, and storage phases and still cause the lube to transform itself rapidly as required through the firing phase. But we don't want the whole mess to go completely to water in the barrel, we want that soap matrix to hold the thinned oils together all the way to the muzzle. It took a few years and a huge team effort to get this far understanding what's going on, and to find a few different recipes that will not only do what needs doing, but do it in a wider temperature range and in a more broad application window than ever before. For a good revolver lube, all you need is a micro-crystalline-ish wax (such as found in Vaseline and Beeswax) and some sort of plasticizing oil (such as the paraffin oil in Vaseline). However, such a lube falls on it's face in extreme heat and velocity or when barrels get long and you'll have to use bullets with huge lube reservoirs to even try to make up for the aforementioned "running out of lube" phenomena. You actually need very little lube on a bullet, but it needs to be the right lube for the job or at least a lube formulated to work in a variety of guns.
Sodium soap has a few advantages over lithium soap as far as bullet lube is concerned. Due to the larger-scale grease matrix of sodium soap, it makes a better 'stop leak' on the muzzle end. It also can take more heat in simple form without melting. It also seems to "dispense" or "leak" oil at a sufficient rate to lubricate without dumping it all out and causing erratic purge flyers, unless of course too much of a super-slick ingredient is added to the mix. Lithium grease can get very purgy, slippery, and provide inconsistent bore friction in hot weather or in very hot barrels, but otherwise makes a very good rifle lube additive. There are ways to fix this, but it requires adding more stuff to the lube. I like a simple mix of ingredients that balance each other out rather than a whole bunch of ingredients that modify this or that and are too complex to correctly balance out or predict unfavorable interactions with other ingredients. Another advantage of sodium soap is it appears to average out bore condition. Stainless-steel barrels and barrels with a high degree of internal polish shoot differently than plain carbon steel or chrome-moly barrels, and pitted or roughly-rifled barrels are different still. Finding a lube that works in all of them equally is pretty much impossible, but sodium soap helps to equalize the way they all shoot with a minimum of seasoning and it also helps keep a consistent bore condition without having to stop and clean periodically.
SL-68.0 has some small issues best described as bumps in the road of temperature/pressure flow throughout its functional range. One of those bumps is not having much of a long-chain, unbranched wax in the middle of the melt curve. Another is a tendency to leave a cooled residue that has a tiny bit more resistance to the bullet than hot residue. The addition of a medium-melt paraffin wax can be expected to achieve that, and also to add a measure of cold-weather, cold-barrel consistency by making the bore just a tiny bit more slippery than what SL-68 leaves behind. Essentially, paraffin is something I was hoping would kill two proverbial birds with one stone and generally improve the shooting consistency of the lube from a cold barrel in mild to cold weather without sacrificing the top end of speed or temperature by making the lube too slick.
Did that make any more sense?
