I'm thinking more of a find relic.
Say you have been in the underworld or in a mass pvp zone where there is a lot of death. You have a very slight chance of finding a rare item, a relic, the relic is a random weapon with increased stats, all done quite randomly so you have have say a bolter with one less round in the mag but does almost twice the damage.

These weapons of course will be easy to spot in a pvp case, so people will know when there is someone stronger near by, for balancing, there should be none, you took forever to find such a great relic, so you are rewarded for it.

Another idea to add to this came from a thread a fair while ago: What if our weapons could tell a story, say you have killed many tyranids with that weapon, the weapon has a short story of how 'insert player name' killed such many xeno's and the overall value of the weapon increases. The more the weapon is used and traded amongst players, the larger the story is. So after a year of being traded, without being sold to an npc or something that would reset the stats of the weapon, then the story goes from:
'This bolter has been through many encounters with tyranids, slaying many of the xenos, it is a relic worthy of the title, Xeno Slayer' to something like 'The bolter known as Xeno Slayer has been held in the hands of the Emperors finest through many battles, it is recognized instantly by any one who sees it as a truly grand weapon. The Xeno Slayer carries with it the seal of 'enter seal here' to show the true might of the empirium.'

Such stories would be pretty cool to read and the small bonuses they get will show just how good they were. And of course there has to be some way to stop all weapons from doing this, such as selling the weapon to a lets say techpreist for resources to further improve your gear.

Losing gear is the quickest way to losing a player base, because only the hardcore will play it, and usually the hardcore is the minority.......If I earned my big ass badass hammer and I die and I lose it, I will quit the game, because what is the point if you make a awesome weapon and you because lag got you killed? Now you just lost a weapon and it was out of your control.....fuck that

I'd like to be able to sell my weapons for different ones

I was thinking about capturable relic:
Let's say there can be like 1 or 2 on whole planet,and it starts with random pvp/pve drop.
Once aquired it can be captured by some who killed the carrier.
Relic uncaptured for X minutes disappear.
Friendly fire destroys relic.
Relic carrier gives armor/capture speed boost.
Relic carrier is visible on map for everyone.
Etc.
Maybe in our *private* rooms we can have some gallery with worn relics

edit: some time ago someone was saying Relic are going to be rewarded for exceptional duty in actual sector/planet

I would like to see a progression system for personal weapons. It could eventually reach relic or named status. It would encourage players to really stick with a weapon for a good amount of time and would add a lot to the feeling of really being in the lore of a great battle. I wouldn't go to far in actual stat upgrades though, more cosmetic with some performance enhancing customization options.
Of course a mission to find a Master Crafted relic would be a lot of fun as well. Though it would probably have to have more of a strike force buff then just be super powerful. Like being able to use the bearer of a relics leadership value or adding +1 atk to the attached unit on the TT game. Plus it would make it easier to decide who actually gets the thing.

I have read all of the posts and i think i have come to a verdict

Relic is the highest and the best weaponry/armor out their i think everyone can agree with that and i think what cupcake said is helpful the weapon needs a story but it shouldn't be lost in the feat of battle but if it is recover per say like a chaos space marine squad kill a loyalist marine with a relic they can take it and contuie its story but corrupt it as well to change its story make it more evil and if they that chaos marine dies it can be taken and attributed and purified with seal and stuff but you get some negatives to using the said item but if its a relic thunder hammer i think it should be tank away from you if you work you ass off so hard to get that relic and other things. The Space hulk idea for raids and dungeon crawls are a good idea but i think that is more of an event than anything so if you a termi and you find The coolest looking lightning claws and relic lighnting claws but its been tainted by chaos and you kill what evers guarding you should be able to keep but you dont own that relic yet if you die that per said relic is lost because you have purified it yet so you lose it but if you come back per say the next event it has a percent chance to get it and could get it again but you can sell the relic but you would be a stupid turd if you did that

That's recent blizzard way to give everybody a legendary if one makes few quests-meh.

Keep in mind orks are very fond of looting, whether it be enemy forces, or other orks.