Are petroleum-based products prone to produce hard residues with black powder? A common controversy about black powder is lubricant composition. Some people tell this is a bad idea to use any petroleum based products in such lube because it will produce hard, difficult to clean residues.

As far as I know, in the old days, gunners used mostly mutton tallow in order to lube their bullets, and most animal-based grease have been found an easy (available) and efficiant way for that use.

Now we can avoid the problems of stinking, liquifying or decaying animal greases, and some people tell they used petroleum jelly or lithium grease for decades with no particular problems. Unfortunetaly, other people disagree, and the exact recipes are so numerous nobody can give me rationnal and definitive answer.
Looking at classic lube recipes teach us there is no consensus on such questions :


  Historical Black Powder Bullet Lubricants
  
  Composition of Extensively Used Bullet Lubricants
  
  (E.H. Harrison, American Rifleman, Jul. 1965)
  
  
  U.S. Army 1855 - 1 beeswax, 3 tallow.
  U.S. Army 1861 - 8 beeswax, 1 tallow.
  U.S. Army 1873 - 8 bayberry wax, 1 graphite.
  U.S. Army 1880 and thereafter - Japan wax.
  Sharps Rifle Co., 1878 - 1 beeswax, 2 sperm oil.
  Massachusetts Arms Co. (Maynard rifle), 1890 - 1 beeswax, 3 tallow.
  Marlin Firearms Co., 1891 - 1 beeswax, 4 tallow.
  Smith &amp; Wesson, 1891 - tallow.
  H.M. Pope, about 1900 - 3 mutton tallow, 2 bay wax, 1 beeswax, 1 steam cylinder oil, .2 of 1 acheson graphite. The bay wax could be
  omitted.
  Automobile door latch stick lubricant, U.S. Patent 1,920,161
  (1931) - 5 paraffin wax, 3 petroleum jelly, 2 oil.
  A large police department, 1962 - 1 beeswax, 1 paraffin wax, 1 cosmoline. Notes: "Cosmolene" in this context refers to dark
  petrolatum with no anti-corrosion additives. Refined yellow petrolatum
  (petroleum jelly, Vaseline) may be substituted.
  Any mixture containing paraffin wax must include a plasticizer, such as petrolatum. Microcrystalline petroleum waxes may be used
  as-is.
  The 1:3 beeswax/tallow mixture (or any composition composed mainly of tallow) is probably the most traditional choice for "primitive"
  shooters. The 8:1 mixture is rather stiff, and better suited to
  conicals, paper cartridges, and the like. For paper-patched bullets,
  I'd be inclined to try the Sharps formula, substituting Dexron II/III
  automatic transmission fluid for the sperm oil.
  


Could someone explain or quote some good source explaining if and why petroleum based lubricant will produce such disagreement with black powder?
The answer may be more simple than some may expect, I start with Black powder, which contains, to quote:

Black powder is a granular mixture of

a nitrate, typically potassium nitrate (KNO3), which supplies oxygen for the reaction;

charcoal, which provides carbon and other fuel for the reaction, simplified as carbon (C);

sulfur (S), which, while also serving as a fuel, lowers the temperature required to ignite the mixture, thereby increasing the rate of combustion.



Next, the warming of an organic together with sulfur can produce a volatile sulfur-containing compound (see, for example, 'Reactions of sulfur with organic compounds XXI. The action of sulfur on 2-thienylchloromethane and di-2-thenyl sulfide').
Further, mixing of the new compound with carbon powder could account for the observed product especially after evaporation of all volatiles.
Note, per the comment: &quot;problems of stinking, liquifying or decaying animal greases, and some people tell they used petroleum jelly or lithium grease for decades with no particular problems&quot;, the precise sulfur-based product, if any, created could account for the differences reported.
Also, this proposed explanation requires an element of heating, which likely accounts for the development of the reported problem over time.
So, to precisely answer the question: &quot;Are petroleum-based products prone to produce hard residues with black powder? Yes, per my assessment.