The firearm rules by Ken Hood are probably more real-world accurate, but without more examples, they aren't all that useful. I'm not going to work though the design features to see what comes up, I want examples ready to use.
Privater Press published a free 2-page pdf called Firearms Basics v1.0, which closely resembles the above chart. Here's the sample pistol for comparison:
Small Pistol: This weapon’s main virtue is that it is easy to conceal, being only 9 in. long. 400 gp, 2d4 piercing, reload 1S/DC6, crit
19–20/x3, range 40 ft., 4 lb.
Just to note: NPCs with awesome weapons skills probably have specific feats that go with them. It's not just the weapon.
P.E.A.C.H. Please Evaluate And Critique Honestly. Being nicer and kinder doesn't hurt either.
Please, please, please when using non-core material, cite to the books. There are too many books to wade through to find the one with the feat, special ability or spell you use.
I've got a red
pen and I'm not afraid to use it.