Grease was used by the U.S. Military as a preservative when arms were shipped from the Arsenals to the military units, but they were then cleaned and stored with oil on them and not too much oil. They knew that arms stored for long periods with grease or too much oil would damage/ruin gun stock wood.
Springfield Armory stored 1863 Rifle Muskets left over from the Civil War, all the way up to when the Armory closed in 1968, by them being placed in large wooden two tier cabinets that came to be called “Organs of Muskets.” They were not stored with grease on them, but rather oil on the iron/steel parts only and wiped down afterwards. Before they were shipped out during the Civil War, they greased them down for shipping. In the 1980’s, Springfield Armory NHS was cleaning the rifle muskets back to the original condition on a couple “organs of muskets” they still had and when I saw them, they had about half the muskets cleaned in one cabinet. There was no grease on the muskets.
Springfield M1903 and M1 Garands were coated with grease for shipment to military units, but they were also cleaned when they arrived and then only used oil to preserve them. Military instructions called for cleaning the grease off Rifle Muskets through M1 Garands when they arrived at the unit and then grease was not allowed as a preservative.
During the huge rebuild programs of the post WWII era, beginning about 1947, they had dry preservatives they used on M1’s, M1 Carbines, Thompson .45’s, M1911/A1 pistols, etc. that they sealed up in what looks like oil drums for long term storage and so the drums could be placed outside for storage in “secure” areas. The idea was to save on the cost of building more warehouses to store them.
Now metal spare/repair parts were stored in grease for long term storage, of course. Replacement M1 and M1 Carbine stocks were often stored for long term storage by using a heavy brown color cloth and then a green color cloth later. Both of these types of cloth were waxed, but not greased, when used for wood stocks and hand guards. The wax was meant to keep them from absorbing too much water vapor or in case the stocks got wet.
Where we see the M1903’s, M1903A3’s, M1’s and M1 Carbines coated with a heavy coat of grease from CMP, those rifles came back from allied governments overseas. The worst cases of grease/oil impregnated rifles that CMP has sold over the years are the guns that came back from Greece. You can identify them by the light tan color grease used that is more like tallow than what we think of petroleum grease. Of course, some of the guns that came back from Greece, were still in the original grease packing that was done by U.S. Arsenals when they were shipped overseas originally. It was just that the Greeks never bothered to clean off the preservative shipping grease and then oil them, as was the required procedure for U.S. Military Units. Also, some guns that came back to CMP from the Netherlands had thick coats of petroleum grease, but many came back oiled and fairly dry.
Gus