Hey Mac Users, I've got a Beta Version of my SR3 Firearm Designer up and on my website at:
ShadowGhost's Web Mac OS X Shadowrun Software
Nothing to install, just unstuff and use.
If you don't have the Canon Companion, you won't know what a lot of options are for.
Guns you create can be saved, opened, modified and resaved.
Let me know of any errors, bugs, or mistakes (i.e. errata, wrong amounts for FCU and DP etc).
And let me know what you think, either via PM, or email (on the website).
Enjoy!