There is also 200 12.7mm rounds in a box right next to the trunk.
(The contents of the box respawn as with all my mods)
Stats were figured up by applying the Honest Hearts Beowulf stats to a standard Service rifle, ROF was based on the Assault Carbine/Colt Commando DAM was buffed to match the Brush Gun/Marlin Model 1895 as Google told me Beowulf ballistics are roughly the same as a 45-70 rounds.
And before I get angry comments; "Recoil" in fallout is caused by firing animation bullet pattern accuracy is determined in GECK by 2 stats "Min Spread" and "Spread" just because it looks ADS your bullets are MW2 ACR accurate they really aren't, stand back 100 feet and try to pop one of the NCR guys at the 188, You probably won't be able to do it in one shot.
This weapon does 75 DAM a bullet and fires 12 rounds a sec BUT only has a 10 round clip with 2.5 min spread and 10.0 spread couple that with the rarity of 12.7mm rounds and you have your self a perfectly balanced niche weapon!