"Tactical run and gun"?
Is that some sort of Olympic event?
Or something for SWAT types to do?
I've run my FAL (full size R1) for nearly a decade alongside other officers who are packing AR's and have had no problem keeping up with them.
Is the gun a bit heavier? Depends.
So many tactical tommy's hang enough sights, flashlights, rails, and doohickey's on their AR that they actually weigh more than my loaded FAL.
I can't carry as much ammo as they can? Fer pete's sake. How many rounds are you gonna put down range? Every bullet you fire has a lawyer attached to it, from the instant you fire it to the time it comes to rest, you are responsible for it. I'd rather use only one bullet (or less) to end a problem and have the rest along for the ride.
I pack 5 mags for the FAL and the AR. That means 100 rounds for the FAL and 150 for the AR, and if I need more than either of those, it's gonna be more of a situation than I can handle myself. Heck, most of the time I ran with the mag in the gun and a spare tucked into a pocket on building searches and other call-outs.
I've shot critters with both the .223 and .308.
The last I shot with the .223 (55gr SP) went way too far considering the hit. A shot from right to left through the diaphragm, heart and lungs, exiting through the front of the chest and the mutt still went 50+ yards, biting, snarling and attacking everything it encountered.
I'll stick with the .308 for anything that may bite, scratch, fight back or shoot back. For hunting, even more so.