I saw an effect in relation to that in the FSX misc section, first couple of pages. If not there, then try the FS9 Misc section.

jsimsack wrote on Feb 13^th, 2009 at 4:46pm:

Hmmm, try IL2 sturmovik, it is pretty much FS with a less open world.

Adding an effect that shows the muzzle flash of guns is possible and quite easily done for any  plane.

Adding guns in the modeled sense in that you can see the actual gun itself, and not just the effect, is quite difficult, and quite impossible without the original source files.

Generally, if a plane has guns in real life, they are usually on the model. If not, then they are left off. Not much point to having guns in MSFS anyway, they don't really do anything but look good, and sometimes flash with the proper effect added.

And talking a modeler into modifying their work is also near impossible. You are really better off learning how to do it if you want custom work done.  In the year that I have been on this forum, I have not once seen a request for a custom model get taken up. There is just WAY too much time and work involved, and most modelers are concentrating on their own projects which require an intense amount of dedication to complete.

Pick up GMAX, it's free, and start with the tutorials, and given time and dedication on your part, you'll get it. Then you can make all the planes with guns that you want.