I notice the item in your inventory is labeled as Jar, Pistol Powder. If I recall correctly, this is the item sold by Vendortron, and is SUPPOSED to turn itself into the weightless item of Pistol Powder (not Jar thereof). I think your Powder Jars might be bugged - try giving things a look in FNVEdit, see if anyone's messing with the jars or their scripts.
Yes, you're not actually intended to ever have those jars of powder sitting around in your inventory, but they're notoriously buggy. There are various fixes around for them, I think.
Actual pistol/rifle powder used in crafting is weightless by default, as mentioned.
6 comments
Actual pistol/rifle powder used in crafting is weightless by default, as mentioned.