The Katana syndrome holds that Asian martial arts and especially sword craft was highly superior to that of Medieval European techniques and blades. Thus the katana is the ultimate melee weapon and should deal out more damage than a European longsword. It has the best grade steel, best edge etc.
Katanas are bitching. Samurai are bitching. I just got through laughing and screaming and misting up over the final season of Samurai Jack. However, Toledo steel was the best in the world at the time in terms of flexibility and durability. Many well made European blades were every bit as deadly as the Katana. For that matter European warriors had a better grasp of technique than stand there and taketh it whilst thou hammer the other guyye. But see this mini-series called Shogun came out in the 80's. Everyone got into Asian culture (a good thing) and gamers got carried away.
So if you're going to write up a bunch of new weapons, say, you want your stuff to stand out and some people believe extra damage dice or points or mods or whatever is the way to go. People building a new pistol will obviously want it to be better than previous weapons and that means more damage, right?
Not really. A lot of firearms have gotten modifications to make them better at a specific job. The same holds true for most other equipment but firearms, weapons in general, are usually the best mass production technology people have. As my character Luch might remark, you can learn a lot about local technology and culture by what people are trying to kill you with.
A gun that does 4d6 damage as opposed to 3d6 won't do you any good if you get nerfed before you can draw it or arrested before you complete your ... assignment. Concealment or just ease of use is extremely important for weapons. If they're hard to tote about you might set them down at the wrong moment. One of the most important features of a sword for example, was that it could be worn sheathed at your side. A spear or axe had to be carried constantly and it was a pain in the axe err ass.
Pistols were drasticaly inferior to rifles but again, they could be toted about fairly easily. Reaching for your shotgun could get you killed.
So I'm writing up some diesel-y weapon and equipment stats and I find I have even less incentive to vary damage than usual. See my products are geared mainly for Cepheus Engine or White Star folks. Cepheus Engine caps most slug damage at 3d6 because, hey, shooting right through your body places an upper limit on what a bullet can do. Similarly in White Star damage is based on the highly abstract hit points. Hit points, we've been told, represents the ability to turn a major injury into relatively minor cuts and scuffs through skill, experience and luck.
If you're lucky enough to avoid a bullet, beam or blade its damage potential doesn't really matter. If you're out of luck the same holds true. A dagger in the heart kills as surely as a bullet.
The upshot on this is my equipment and weapon right ups are going to focus on utility and other considerations. What about a pistol that does moderate damage but is so easy to use anyone can grab it and begin popping (at least at short range)? What about a rifle that collapses to easily store under a coat (I loved the Mass Effect weapons)? Or how about just ramping up the number of charges or rounds or whatever?
I'll note in closing that many weapons (or at least ammunition) are built to specifically limit performance (meaning damage). You might not want a high power blaster for a hold out on your bridge. Yes you'll shoot right through that hijacker ... and your control panel, and your pilot. This is why my 'Trader Carbines' have several types of ammunition for shooting it out on your ship or on theirs.