Some highlights from Sinister's links:
These excerpts are the most valid information from the documents Sinister listed, much of the information is repeated verbatim through several of the texts, it is interesting to note that the vast majority of them are from 1984-2000. Still, some good information.
1) Weapons are also affected by common conditions of the cold regions and the resulting effects on material properties, e.g. increased viscosity of lubricants and hydraulic fluids causing slow response, accumulation of frozen moisture, breakage of cable insulation, and failure of seals. Additional problems include:
(1) Propellants in munitions may have a slower burn rate because of the slowed chemical reactions.
(2) Ice fog resulting from the exhaust from weapons firing reduces visibility in the immediate area and may prevent tracking.
2) Small arms, optical systems, and other equipment used, worn, or carried by the Soldier can be adversely effect by the cold environment. Besides the hazards to Soldier health caused by the cold, equipment may be difficult to use because of material changes in the cold. Some examples follow.
(1) Seals on NBC protective masks may harden and fail and moisture from warm breath may freeze on lenses, eye pieces, and optical equipment.
(2) Exposed metal surfaces on small arms require more frequent application of smaller amounts of lubrication to remain functional and condensation forms on weapons when they are taken from the cold environment into a warm shelter. Condensation that is not dried can refreeze when the weapon is taken back into the cold temperatures
http://www.dtic.mil/cgi-bin/GetTRDoc...f&AD=ADA499912
3) A visibility problem can be
encountered when a weapon with excessive muzzle blast is fired in
temperatures below -3OOF. As the round leaves the weapon, the water vapor
in the air is crystallized, creating ice particles that procure ice fog and follow
the path of the projectile obstructing the gunner’s vision along his line of fire.
When faced with this problem, fire at a slower rate and relocate to
supplementary firing positions.
4) Ammunition. Cold weather can materially affect the performance of
ammunition. The ammunition should be kept at the same temperature as
the weapon and should be carried in bandoleers. Additional ammunition
should be carried in the pockets of the outer parka. Clips and magazines must
be cleaned of all oil and preservatives and checked frequently. All ice and
condensation must be removed.
a. Burning Rate. The burning rate of various types of propellent
charges is affected by severe cold, weapons zeroed under temperate conditions
will fire low when firing ammunition that has been exposed to the frigid
temperatures. This is a result of the propellent charge burning slower due to
the cold.
http://coldweatherclothing.info/Refe...pub/p-1053.pdf
5) Lubrication of weapon systems is another concern when operating at cold temperatures. It is better to fire a weapon dry in the cold than it is to use an improper lubrication that will cause a malfunction during firing. Typically this is not a problem since, CLP does not freeze until it reaches –35° F. LAW (Lubricant, Arctic, Weapon) should be ordered for all weapons and used when range between 0° F to –65° F. History proves that other lubricants have been used effectively in extreme cold weather conditions when LAW was not available to fighting units. Some examples include graphite, kerosene and diesel fuel mix, and winter weight motor oil.
http://www.scribd.com/doc/9702656/Us...Weather-Manual