Presumably that you have some experience in the army (as I have) and/or weapon arms.
No. The main physical activite in which I have experience are running and cycling.
Let's take a real life scenario.
A M16 rifle vs carbine - which has more recoil?
Will a person who has more strength shoot better (handling the recoil effect) than another?
Will having the correct technique (butt between chest and shoulder, release half-breath and hold, etc) help?
In your definition of RPG, I have a scrawny character who wields a GPMG but he is shooting it single-handedly and hits your brawny character wielding a M16 and at the same time, dives down to throw a bayonet at another character 200 feet away.
And? Maybe my RPG is emulating a certain sort of war comic or movie.
I mentioned running upthread. From time to time I have to run from my office to catch my train. I know that the run typically takes me around 13 minutes. Variables that can effect the time taken include traffic and traffic lights (I have to cross some streets on my journey), how tired I am, how much I am carrying in my backpack or in my arms, and what shoes I am wearing. Wearing runners rather than hiking boots improves my speed, mostly because it reduces exertion.
I've never seen an RPG in which the movement rules have regard to footwear - eg in AD&D their are rules for the interaction between hard boots and sneaking, but not hard boots and sprinting. Does this mean that those aren't RPGs? Or aren't good RPGs?
Futhermore, for your example to even get going in an RPG, we have to be keeping track of details like different firearm types, the physical distance between the characters, etc. Neither of those things is essential to an RPG. When I
GMed a session of Marvel Heroic RP, as part of the climactic final battle War Machine (PC) fought an aerial duel with Titanium Man (NPC). War Machine was firing rockets and repulsor rays at Titanium Man. Titanium Man was retaliating by ensnaring War Machine in force rings, and in the end won the combat - flying off to a secret base in Khazakstan while War Machine fell to earth somewhere in Florida (the fight started over Washington, DC).
Here are some of the questions to which I don't know the answers, because the game system doesn't require paying attention to them:
* What sorts of rockets does War Machine use?
* What precisely are the capabilities of a repulsor ray?
* At what distance(s) were the two combatants attacking one another?
* How high were the combatants flying?
* How long were they fighting for?
Some rough answers are possible to some of these questions: as neither combatant is equipped for operations in space, they must have remained within earth atmosphere; and as the combatants can fly at supesonic speed but not fast enough for interstellar travel, the fight must have lasted for some time to make it down the coast from DC to Florida. A quick Google tells me that's a distance over 1000 km, so even at mach 2 it's abut half-an-hour. When I was GMing I didn't worry about this - like my players I am Australian, with a fairly patchy knowledge of US geography, and narrated the falling point as Florid for colour - to indicate a large distance had been travelled - rather than on the basis of any actual calculations.
When declaring and adjudicating actions in MHRP, the sorts of details you're talking about simply aren't relevant. We aren't interested in the size of the gun - we're interested in whether it is Cable, The Punisher, War Machines, etc who is using it!