Personally, I think the penalties for using Plasma weapons have been piled too high; ultra-rare, ultra-expensive, ultra-dangerous, etc So, I thought I'd at least mitigate the "HURR HURR SUICIDE GUN" part. Back in Ye Olde Seconde Editionne there were two kinds of plasma weapons: the current Imperial model which had to recharge, and the Mk I model used by Chaos which didn't recharge but if you rolled a jam with sustained fire it would overheat in a similar fashion to Dark Heresy. I got the inspiration from there.

Plasma weapons fire 2 modes: safe and unsafe .

- Safe plasma weapons have safety buffers and low plasma cell that prevent catastrophic meltdown but require a capacitor to charge between shots granting it the recharge trait. These weapons are used by sanctioned Imperial forces and sold at legitimate vendors.

- Unsafe plasma weapons have had their safety features removed and their capacitors overclocked to eliminate recharge time, but now suffer from the overheats trait. These weapons can be found in the hands of criminal elements such as bandits or smugglers.

- A weapon that is in poor condition or otherwise abused/badly maintained has both traits as normal.

- A player can change a weapon from safe to unsafe (or vise versa) with an Easy (+20) Armorer test. The player needs appropriate tools and workstation and the modification takes 5 hours. A failed test at the end of 5 hours requires the player to spend an additional 5 hours checking calibrations before testing again. A failure of 4 or more degrees means the weapon appears to function but will explode as per a plasma grenade the next time it's fired (roll in secret, obviously).

- A player can make a Challenging (+0) Armorer test to add a selector switch allowing the weapon to be changed between safe and unsafe at will. In addition to a proper workstation the player requires extra parts (100 thrones, scarce). The upgrade requires 10 hours to complete. A failed test requires and additional 10 hours followed by another Armorer test, while a failure of 4 degrees or more causes the weapon to become a bomb as above.

- A player can change the setting on a modified weapon as a free action at the start of their turn, but must wait until the start of their next turn before the weapon is ready to fire.

- Plasma weapons that only have the recharge or overheats trait, but not both, are exempt from these rules.

Edit: when is said Easy(+20) I ment Routine(+20).

I agree with you there. Plasma weapons are woefully underpowered when balanced against the cost, danger and waiting period. Especially now that the Errata gives all bolters tearing.

I like what you are saying but I think you could probably do with going even further and still increasing the damage, rate of fire or having a new special rule.