so its wrong to fire some one that violates company policy?
If the policy goes against the purity of the right to self defense, then yes. This is the right that the second amendment covers and no company should be able to deny anyone this right, public or private.
In '91, I worked night crew at a grocery store. When the store closed, we had some obviously drunk gang members push their way threw the doors as we tried to lock up. When asked to leave, they got angry and one pulled a snubby revolver. An emergency call went out over the intercom, and about 15 employees came to the front to aid the rest of us (this was a grand opening store and a payroll wasn't an issue). Luckily no one was shot, the guy packing was smart enough to leave and the police arrested the remainder.
After that incident, the store manager, who was a friend of my dad's, gave us verbal permission to bring guns to work. Even the deli girl had a .357 under her sweater. This was against the company policy. In the morning, the manager would have us come into the office to show-and-tell what we were carrying that day. We never had any other incidents while I was working there.
In June of 2003, this former manager had handed in his keys and was finishing his last few weeks as a union employee to lock in his medical for retirement. My wife works at the same store, but had the day off. A 30-year-old bagger that had abandoned his job a couple of weeks before returned wearing a trenchcoat and beret (JUNE). He haunted around inside the store for a while before pulling out a "samurai sword" and slashing employees and shoppers. The first victim was the non-foods manager, who was also within weeks of retirement. She was beheaded. From the witnesses I talked to, my understanding was that my old manager and friend was stabbed though the lung and died on the floor from that injury. Many others were cut between the 2 killings.
Police response was within a few minutes, but understandably not fast enough for us to put aside our right to defense. 3 officers entered the store. One with an AR-15, which was used to stop the attacker, who died from his gun shot wounds.
This manager, who let us carry, and even on occasion wore a holstered black powder gun (unloaded) as part of a halloween costume, toed the company line and went unarmed. This company policy didn't do him or his family any good. Company policy should not be allowed to deny any right. On the company's side, they also shouldn't be able to be held liable for an individual exercising that right either - which would be especially an issue in California.
While companies can still set policies like this, it's kind of along the same lines as, "better to be judged by 12, then carried out by six." I'd rather get fired and go home to my family, then get killed by a nut and leave my wife to sort out the aftermath.