I'm looking for these scale guns from hand guns to heavy artillery. MK19 etc. If you know of any links please post them here. Thank you.

ESCI Land Rover 109
http://www.artecar24.com/tienda/ver.php?txt=es&id=511

Hasegawa has a few WWII era Kubel Wagen
http://www.1999.co.jp/eng/image/10039977z6/70/6

and Jeeps
http://www.1999.co.jp/eng/image/10034164z6/70/6

hope it helps

Thanks for the links but these do not say if they are 1/24 scale. Are there not any separate modern day weapons?

No separate ones I know of, although aboiut a year ago one of the members here was working on a set.

the Italeri Land Rover is 1/24 and comes with two GPMG's, Mag 58's, whatever you want to call them, which with a little work can build into M240B's.

I seem to remember the AMT 1/25 Scale Robocop car coming with an M16 and a shotgun.

And of course the Hasegawa 1/24 Jeep has the M2 .50, which is the same as used today, just on a different cradle.

There was an MPC police car that used to come with M16 rifle, shotgun, etc. It has been reissued in the past by AMT/Ertl. Additionally, the Joker Goon Car (from the Batman movie) by AMT/Ertl also included these weapons (the car came with optional parts to build a Gotham City police cruiser). This kit can be had for $5.

the links are all 1/24 kits. I don't know of any weapons only kits in this scale. Good info Sabot, I'm going to look for a couple of these Joker kits now too.
I have a police car from the '90s or '80s from a Japanese company. It has a hand gun and shotgun. I'll look for it this weekend.