What is the purpose of the handle in the drum of the Stickybomb Launcher (and the Scottish Resistance and Sticky Jumper)?

I don't know what it is made for, realistically. It's not like the Quickiebomb where there's the strap to hold the drum together and it doesn't seem light enough to carry around with a belt. What would it be made for?

I know that there are worse offenders than the strap of a Stickybomb Launcher, but it just kind of intrigued me.