The first thing that comes to mind in this thread is the DISGRACEFUL state of American public schools.
To graduate, I needed a lousy ONE unit of science and math, THREE of English, that mostly stressed how to write a stupid "vitae" (something I have never needed in my life), ONE of phys ed, ONE of a foreign language, ONE of social studies...
Do your kids a favor: Make them take three units each of math and science. Liberal (and extreme conservative) anti-logic doesn't work on people who have learned how to think rationally.
As to science, I've seen too many threads on firearms with crap to the effect of, "That's just some guy in a lab (
with decades of education, reams of data, millions of dollars worth of equipment, notes, photos, calculations and tests). I think I'm going to have to side with 'the man in the field' (
who is possibly illiterate, probably not trained in analysis, stressed out, biased and operating in an uncontrolled environment).
This is called the Dunning-Kruger effect:
http://www.apa.org/journals/features/psp7761121.pdf
As to the science in question here:
The recoil will only move the person as a function of their mass relative to the bullet, i.e.: Very little.
The recoil is instantaneous enough and sufficient that a typical recoil-operated action should still function.
Vacuum-safe lubricants include PTFE (Teflon) and buckyballs.
While for thermogodammic purposes, space is cold, vacuum still functions as an insulator. Heat loss or gain is through conduction or radiation only. Sustained fire will require cooling vanes or flutes. An enclosed holster should prevent excessive cooling. A small heat source could be added if needed.
While without atmospheric disturbance a bullet will fly straight, it is still subject to deflection from muzzle blast, and unequal force. Rifling would still be a good idea.
The projectile will eventually slow down from impact with dust and gas particles, which do exist in space, just in lesser amounts. There is also GRAVITY from every chunk of rock and THE SUN, plus planets. Those bullets will stay in Earth/solar orbit and will decay and crash eventually.
And everyone knows the .45 ACP will be firing volleys in salute when the last 9mm is buried.