Would an MSR Pocket Rocket be able to fit...
Would an MSR Pocket Rocket be able to fit inside the 600?
It will. A better option however is the MSR Titan Kettle. The reason is because it has a lid. You can use the Titan Kettle as a cup, bowl, or to boil water. It's the perfect companion to the Pocket Rocket.
The other great thing about the Titan Kettle is that it not only will fit the Pocket Rocket inside, but a 4oz. canister if you put the Pocket Rocket in first. The lid fits on tightly and you've got a perfect set-up that's a whole half-pound lighter than JetBoil!