Advanced laser defense:
Basically a Mk.II version of the basic laser defense. It does 25 damage instead of 5, slightly more range, and has a larger buffer.
Energy per shot is the same. I balanced this by requiring an Efficiency 3 module, artifacts, and laser turret lvl 6 tech upgrades.

Personal gun defense:
This is a lower tech version which uses ammo instead of electricity. It's a low-power turret with high ROF.
Damage based upon ammo which should include bullet tech upgrades.
The only tech requirement is turrets and modular armor, it becomes available early.
Different armor slot shape just for fun.

Notes:
This gun has a few quirks to it.
It's shoehorned into the laser equipment programming structure. When you mouseover it, you'll see the energy storage buffer, this is now the internal magazine but I'm unable to rename it. It refills from ammo in your inventory, can hold a full stack of 100 clips. As it fires, this energy bar is slowly depleted. It then will refill using ammo from inventory.. So there's 1 layer of quirk but basically it uses ammo.

In addition, It will only load from main inventory, NOT from your other weapon inventory. The bullets in your primary gun will stay there.
It also will stop automatically loading when there are only 10 clips left in main inventory. This is another precaution to prevent you from ending up in the middle of nowhere without ammo.

Special thanks to Adil for programming help!

Changelog:
0.1.6 (2.25.17): Update for vehicle grids, AAI, and more damage with piercing rounds.
0.1.3 (8.27.16): Update to Factorio 0.14 (Special thanks to David Merillat). Increased gun cooldown from 2 to 3, it was shooting quite fast.
0.1.2 (8.11.16): Gun returns ammo when removed from armor. Updated tech req a bit, reduced build costs a little.
0.1.1 (7.5.16): Updated for version .13
0.1.0 (6.3.2016): Initial release

Known incompatibility with other mods:
AmmoBox_Autorequest causes crash.
Modded ammo will not fill it.