That's something I'm gonna test.
Although the same round, penetration can differ based on muzzle velocity - which is affected by the length of the barrel.
Hmm.
Sometimes backpacks don't seem to sync so you lose the extra space it creates in your virtual inventory.
Try moving the rubber without a backpack and with small amounts at a time just in case it doesn't sync.
We're selling both, all though rubber is at extremely high demand. We have plenty of orca packages, though.
Prices are all available in the page linked in my signature.
Also 100 rubber would cost 1.15k each.