Plastic canteens and hip flasks take up more volume in inventory than they're supposed to

Describe the bug

While doing zombie laundry with my main character, I happened to notice that slightly more space in the washing machines was being used up than was supposed to be. Looking at the volumes of the items in the washing machine, I didn't see any which had an abnormal volume, so instead, I started taking things out just to see what could have been causing it. Through this, I figured out it was the plastic canteens and hip flasks. The strange thing is, when looking at the items themselves, their volume is displayed as what I expect it to be - 1.50 L for plastic canteens, and 0.25 L for hip flasks. However, when I put it in the washing machine again, they take up slightly more than that. I tested this further by dropping them on the ground and selecting them to be picked up again, and comparing the displayed volume of the respective items to the volume of space they would take up in my character's inventory, which was listed as 1.51 L for plastic canteens, and 0.26 L for hip flasks. The extra volume isn't much, but it's enough to become inconvenient for my efforts to maximize the productivity of every unit of detergent I use while doing large amounts of zombie laundry for the purposes of obtaining clean clothes to be disassembled into raw materials.

Steps To Reproduce

1. Find or debug spawn a plastic canteen or hip flask
2. Either drop it on the ground and attempt to pick it back up again, or put it in a washing machine
3. Compare the listed volume of the item to the volume of space taken up when selecting it for pickup/when it's in the washing machine

Expected behavior

I expect that the listed volumes of the item will reflect the amount of space they'll take up when they're in my character's inventory or otherwise inside something else.

Screenshots

Screenshots can be viewed here.

Versions and configuration

• OS: Windows
  • OS Version: Windows 8.1 Pro
• Game Version: bc28921 [64-bit]
• Graphics Version: Tiles
• Game Language: System language []
• Mods loaded: [ Dark Days Ahead [dda], Disable NPC Needs [no_npc_food], Bionic Professions [package_bionic_professions]

Additional context

Yes, I also tested it with a new world with only vanilla content and mods that are loaded by default, as you'll see in the version/config part. I also tested this with the 2.5L canteen and the wooden canteen; both had the same amount of volume taken up in inventory/washing machines as their listed volume.