I don't have Book 4, so it looks like I will need to find it. So let me ask this - does book for have more weapon categories?
Ruger did make a full AUTO version of the Mini14 in the 1980 that targeted law enforcement and smaller militaries or para-military units.
(remember seeing one in Germany in the early 90s right after a bank robbery that was straight out of the movie HEAT, with carnage all over a small street in Wiesbaden).
I think this rifle was called the AC556 or something like that.
I am just finding a little odd that a 5.56x45mm would use the same stats as a 7.62x51 or larger AUTO Rifle stats.
FWIW, a bit from my own thoughts.
Way back in the dark ages of 80's gaming, I was just as huge of a weapons nerd in my games as anyone else. "No, I should get a bonus for using "X" because it's so much better than generic "Y"."
Since then, having dealt with 2.5 wars overseas, plus a law enforcement career, along with 15 years of teaching firearms professionally in conjunction with those... and, a view towards more "simplification" rather than "detail nuts" on my games, my thoughts are slightly different.
Sure, there are differences between 5.56 rifles and 7.62 rifles, and what they are employed of, and some terminal effects/range and the like... Just like, (bear with me) there are differences in performance between a Honda Civic and a Dodge Charger.
BUT - on a 2D6 range of effects, such as Traveller, they really boil down to being pretty miniscule.
So - IMHO - I'd go along with what later posters on this threat pointed out. All well and good to have "This brand carbine is known for good handling, +1 DEX, that brand is great at autofire and can use those rules." But, trying to differentiate between every slug throwing long arm is going to get old, quick. It's the same reason the game has a limited number of blade weapons, and you can extrapolate close matches within those categories.
Just some food for thought.