Chris, when we started out on this "thing" together we all had been playing on our own for a while and sort of had our own ideas/requirements in mind. I even started a thread one time to poll as many people as possible on a "world standard" test of bullet lube. We came to a consensus on a routine pretty easily for anything from about 20° to 120, for any pressure or velocity. That was two, ten-shot groups fired in five minutes or so each with a cooldown to ambient in-between, repeated again no sooner than 24 hours later and preferably a week. Then repeat the same routine of 40 shots in the warmest temperatures expected, the lowest, and somewhere in-between. In tandem, if possible, perform the test with a low-pressure handgun, medium-pressure mid-bore, and high-pressure mid to small bore. All well and good, then Pete comes along and discovers that our test protocol goes completely down the drain in REALLY cold weather, so he had to invent one of his own which I consider it's own "world standard" until such time as lube technology makes something that will hold POI from minus 20 to warm barrel or even hot barrel another 40 degrees colder than our "normal" test protocol and still will shoot well in extreme heat. As far as I know we haven't come up with a recipe yet that will hold a tight rapid-fire group in sub-zero weather with a normalized rifle and ammunition. It's enough of a job just to get all the first shots to hang together at that temperature. Personally, I'd like to see some rapid-fire strings with various, known-good lubes and load combinations below zero to see how far we have to go, so feel free to invent your own testing protocols for this, but keep what Pete has written in mind as you do.
I doubt you want all the nitty-gritty theory and condensed "learnings" from all our experiments, but if you do, keep reading. It took me a couple years of earnest compounding and testing before I learned to quit thinking of bullet lube as a "lubricant". It simply isn't. In fact, bullet lube's function is a tribological paradox.
The only reason we get away with various oils in our lube is that they plasticize the waxes and make them the correct starting viscosity, not because of their individual film lubrication attributes as actual oils. So those oils fool us in what they're doing, and if we know anything about machinery lubrication we know that super-slick, EP esters and PAO synthetics will maintain film strength and flow through a much wider temperature range than ordinary dinosaur squeezings so we turn to those super-lubes to handle both extremes of bullet lubrication temperature. WRONG. Think about gilding metal jackets (and the research into alloys between the two world wars to minimize barrel fouling) and also the various epoxy bullet coatings and even paper jackets to see what is really required of our waxy "lube".
All, really, that is required of a bullet lube is that it keep the bullet-to-barrel seal patched up from zero to maximum bullet speed, and itself not alter the friction characteristics of the bore in any shooting condition we encounter, even after being mixed with powder by-products such as graphite and carbon or moisture either liquid or frozen. Sound simple? BUT wait, there's more to it for it to have those simple properties. The lube has to actually liquify at the same rate as the bullet accelerates (microseconds per foot) and it has to provide the same surface friction coating in the bore whether in liquid state or frozen solid. Lube can't absorb heat fast enough in that time frame to change phase, so it must instead be pressure-activated, and that is done with a balance of wax chain forms and straight-chain oils. With a good bit of difficulty I've managed to make several different non-melting lubes and they all failed miserably even at pistol velocities. If the lube doesn't flow correctly at high speed, it literally becomes an adhesive in the barrel. Plenty of lubes work consistently after the first shot or two knocks the chill out of the barrel steel and softens the cold residue, but few manage to provide the same resistance to the bullet hot or cold.
What seems to be working the best overall, hot or cold, is to start with a blend of branch-chain, micro-crystalline, long-molecule waxes (60-80 molecule chain length), add in some straight-chain paraffin waxes, and blend that up with some beeswax to attempt a full-spectrum wax. A petroleum wax can do this, such as the infamous Unobtainium Navy wax some of us have tried. That wax has both straight and branched chains going from single digits to something over 100 molecules if I remember correctly, and thus has an extremely long and predictable "mush phase" from solid to liquid. Then there needs to be a middle modifier (usually an oil or fat of some kind) to plasticize it to the correct starting viscosity, which turns out is pretty soft if you want to use it at low speed or low pressure. That's it for just below freezing to about 90°. If you want to go hotter, you'll need some sodium soap to control the flow at the end of the barrel and not get blow-out past the relax point of the bullet. If you want high velocity, you'll also need to add a tiny bit of high-temperature, low-viscosity, EP wetting agent like Castor oil or polyolester oil. Same for the extreme cold as far as I understand, but I don't believe the soap is really necessary in extreme cold, the point of my testing was to see if the soap could TOLERATE cold successfully and thus could be left in as part of a true, all purpose, anytime, anywhere, anytemperature, anygun bullet lube.
Getting the balance of the waxes correct not only lets the lube pressure-liquify and speed-liquify to match bullet speed in the barrel, but also gives consistent bore friction. Paraffin is slippery when frozen (room temperature frozen or frozen frozen), but actually fails as a lubricant and increases friction when liquid. Micro-crystalline waxes are the opposite, being very adhesive and cohesive when solid (frozen) but providing a lubricating film barrier when melted. This is why you have to have the properties of both in a good lube to balance friction characteristics throughout the temperature and phase changes. Having a pretty decent balance of solid vs. liquid friction properties in a barrel is also why ordinary bee spit is so good in most lube formulas, in case that one kept you up at night as it did me for a long time. Those attributes come to beeswax by virtue of the broad arrangement of various monoesters, diesters, and natural micro and macro wax strains which just happen to come pretty close to matching the highly dynamic needs of a speeding bullet.
Lithium soap grease has always bugged me. It fails in high heat due to loss of oil-retention properties when you need them the most ("goose chit syndrome"), and it fails in the cold because below 20°F the tight matrix really starts to resist flow. Go try to lube your ball joints with a grease gun at 15° ambient and you'll know what I mean. That means any lithium soap left in the barrel in the cold makes MORE friction until it is warmed. Since CORE is the name of the game, Lithium soap works against us and needs lots of other additives to extend its useful temperature range, which reminds me of a doctor prescribing three additional medications in addition to the one you really need just to control all the various and sundry side-effect. Several of us strove to isolate and test individual ingredients as much as possible to distill the ingredient list down to just those that did the most of what we needed with the fewest side-effects. Sodium soap works in barrels so hot they'll blister you, and also in extreme cold if Pete and Mike's testing is any indication. But sodium soap needs to be mixed with a wax, and gelled properly to work. Wax and soap matrix are symbiotic in a hard-working bullet lube, you can't have one without the other once you get into rifle velocities and uncomfortable temperatures.
Oh, and leading. Leading is and always has been the least of our problems. If you get leading you have a pressure/alloy/bullet size problem, not a "lube" problem.
CORE is the whole deal. Make that consistency happen in the bore all the time with a lube that seals the bullet in the bore for the whole trip and flings off at the muzzle and you've got it licked. Hopefully this will give you an idea of how some of us got where we are in our current and on-going quests, and maybe what to look for in a good lube recipe.
OK, so blah blah blah theory, etc. Chris wants samples. You can cover a LOT of bases with JonB's SL-68B. That lube pretty much represents the sum total of my own testing, experience, and understanding, and if anyone wants to know what MY "Extreme Lube" recommendation is, as of right now that is it. But this is an extreme COLD test thread, and really the only reason I even posted here having no experience with such is that I know the soap lubes that Starmetal and I developed have reasonably withstood Pete's tests.
