Let's talk about xeno and chaos weaponry retrieved from the battlefield.
What would be the destiny awaiting a xenotech artifact retrieved? As far as I know, a dangerous and unuseful one would be destroyed, otherwise recovered for further investigation, by the Techmarines on the Watch Station or given to the AdMech Magos, with the aid of Ordo Xenos maybe. Retro-engineering, adaptation and that kind of stuff. Like the Ghost Field or the Runecaster in Rogue Trader [Corebook, pg 207-208].
Is that possible to cleanse the chaos taint with the aid of Ordo Malleus AND\OR Chaplains to redeem a fallen weapon and help the good fight? Maybe a little radical, but DeathWatch is beyond that I think.
Edited by [S]ir[B]ardiel