Guns

PepperBall,  Napalm cannon, Flame thrower under category http://sasecurity.wikia.com/wiki/Category:Guns

Net gun, http://www.protectglobal.com/  Fog dispersion system ,  http://www.smokecloak.com/en/

Gauss gun,Electric Cross Bow Rapid and automatic firing of bolts.

https://www.shotspotter.com/ trivial to Patents hack via Fronting company

Airtank airguns diy tank containers for co2

https://www.youtube.com/user/DemolitionRanch/videos demolition ranch channel

golfball
https://www.spudfiles.com

https://youtu.be/9ydJXOTf1-4 vacuum by nighthawkinlight channel.

https://youtu.be/wyB0GE3eVjU, https://www.youtube.com/watch?v=PqNc-KbdO1U air cannon valve , air actuated ball valve for rapid discharge of gas. It uses rack and pinion motion for linear to rotational as the ball is rotated to release the gas. See quick release exhaust valve from Net gun.

https://youtu.be/cBazTqyIp2w collinfurze semi auto potato cannon

https://www.instructables.com/GolfballAntennaNerf-Cannon---Build-One-That-Shoo/

https://www.youtube.com/watch?v=PqNc-KbdO1U air powered projectile launcher

https://www.youtube.com/watch?v=cKmbjF-sL3Q tennis ball cannon

https://imgur.com/bdT8vVv golf ball cannon, rotating cartridge

https://tshirtgun.com/ Two co2 canisters with Patents electronic firing mechanism.

https://usamodelkina.ru/13467-pnevmaticheskij-arbalet-po-motivam-metro-2033.html?utm_referrer=https%3A%2F%2Fza.pinterest.com%2F

https://www.youtube.com/watch?v=2TfUKuPdhH4 airgun

links
build sentry tower, https://archive.is/EOGUX, https://web.archive.org/web/20170612052645/http://projectsentrygun.rudolphlabs.com/make-your-own/setup-the-psg-codeand , https://github.com/sentryGun53/Project-Sentry-Gun object tracking ,https://www.youtube.com/watch?v=nTs7VRFV36c, with Object tracking.