I hope the BAR isn't reality based, but somehow "lore" related, as the "real deal" is pretty much, (as far as Fallout tech goes) a non-starter, not to mention the fact that you need an entire new ammo category/caliber to make it run.
For its time, it was a devastating weapon, but that time passed very quickly, to be replaced with what we now refer to as an "M-14". Face it, a "SAW" that held only 10 rounds, however effective they might be, does nothing for the "spray 'n' pray" doctrine of modern (i.e.-post BAR/WWI) combat weaponry, especially once you need to mitigate the effects of recoil on those 10 rounds.
The BAR uses 20 round magazines. And unlike the BAR the M-14 was totally uncontrollable on full auto....the Army eventually removed the selector switch on issued rifles for that reason. Yes, they are obsolete as far as modern warfare goes but the Courier has the luxury of tooling up based on the player's personal style. If I can shoot my way to victory in this game with a semi-auto sniper rifle, a pump action shotgun and a single-action revolver...I can do it with a BAR too.
A "Hunter's Rifle", in the same caliber would be much more effective. The "lurv" for this beast must come form some WWII FPS that glamorized its role in actual effectiveness...
You mean the Hunting Rifle we already have. And the BAR was legendary long before WW2 shooters came to be.
EDIT- After looking at further posts, it seems that the general consensus is that the BAR is (and somehow "should be") a .308 weapon, when in fact it was actually .30-06...
If such is true, at least from a gaming standpoint, it still would be inferior to an M-14, as the later model had several more features to increase durability, accuracy, and ammo capacity.
In talking about the BAR being in game, it's assumed the devs would make it .308 rather than introduce a new caliber (.30-06).....a deviation that is acceptable because the logic behind it is clear. They can always up the damage slightly to reflect the .30-06's greater power. And the M-14 is a fine service rifle but a awful SAW, and wasn't used by the Depression era Bank Robbers like Dillinger and Bonnie & Clyde......or in WW2 for that matter. And the BAR and M-14 both used 20 rd mags. People who choose to carry the BAR in game will be doing it for stylistic reasons....not just to be uber like some kid picking the M-14 EBR in MW series without knowing a thing about it's history.