If the goal were to maximize gun damage, and it came down to picking 1 of these 2 skills, which skill would provide the greatest increase in overall gun damage (assuming aiming for crits as most people should be). Scorching RPM’s (increased crit damage) or Armored Infantry (increased gun damage)?
You have to ask the question which will increase your DPS.
If you’re hitting crits for sure RPMs. If you’re not hitting crits it’s going to come down to fire rate vs gun damage. In a real scenario RPM is going to benefit you much more than VI as long as you’re using appropriate guns. As in an automatic, not a semi automatic.
Also if you use short fuse RPM will increase the damage there as well for some reason. And it increases Iron Bear’s damage.
VI does give a slight damage reduction but the gun damage is gone every time you lose your shield.
If your actual question is which will give better gun damage, well VI will because RPM doesn’t raise gun damage.
RPM is better in the fact it’s universal, as it doesn’t depend much on factors where you can easily lose it; like your shield going out for example. It does have a downside in that you’re likely to run out of ammo faster simply because it makes your guns shoot quicker; but this can be offset by investing a point into Redistribution and having a class mod that boosts it. However, that skill depends on you consistently landing crits to get the most out of it, but the emphasis on doing so goes well with RPMs crit damage boost.