I just picked up Aresenal a couple days ago, and got stumped on this. A few weapons, like the HK Urban Combat and Urban Fighter say they cannot be further modified. Does this mean they also can't use the barrel, underbarrel, and top mounts? I've spent the last half hour doing searches to no avail for more info, but my search-fu is only rank 1 and I failed my extended test. Thanks for the help!

Modifications (as in the section Vehicle and Weapon Modifications, which using a numeric value of slots) cannot be added. Accessories (using barrel, underbarrel or top mounts) can be added.

Happy hunting!

This sounds great and I want it to be true, but I was wondering if the books supported this answer at all?

Kinda but not really.

Accessories (according to the book) are modifications and have to to be modded to make them interchangeable. Short answer is "no," you cannot do anything further to them. Also remember that anything smaller than a SMG has fewer mount-points.

The people who made this game failed when it came to firearms, and I kinda want to take them to a IDPA match and a 3-gun shoot sometime and let them go through the courses and see how things actually work.

That's Arsenal, my friend. The "cannot be further modified" condition isn't very common, so there isn't any specific about what it means, but that quote above makes the distinction between modifications and accessories very clear. Ergo, if accessories and modifications are different, and you can't use modifications, then there's no reason you can't use accessories.

Also, logic is never a good way to MAKE an argument in SR, but it's a good way to check if an argument makes sense. For example, the HK Urban series are high-tech guns with a very specific, easily concealable non-metallic composition, so it makes sense that you can't open them up and mess with the innards, or else you'd ruin something. But what's stopping you from putting a silencer on the front of the HK Urban Fighter heavy pistol? I don't see anything.

or to combat...

and yet people take the time to not only play the game, but find this forum, create an account, and rant about how poor the rules are...

We need a button next to Quick Reply labeled "I Believe." Hitting that button makes an automatic post about how the rules don't make sense when compared to real life and that the OP should stop worrying about it.

Then the phrase "mashing the 'I Believe' button" takes on new meaning.

This.....

Accessories ARE NOT Modifications by the rules

Well Said Draco18s