Need help with making a jig

[Mike Campbell]

I am in the process of making some models of WWII machine guns for the kids (and me!!!) and my next project is to make a 1910 Maxim water cooled machine gun. It has a round water jacket that covers the barrel and has long grooves made in it. This will be my first attempt at cutting designs in round stock and I am not sure how to make a jig to accomplish what I am looking for. Any help would be greatly appreciated.

Here is what I plan on building.
maxim191027.jpg
Capture.jpg

[Kent A Bathurst]

google "how to make round fluted columns"

[Mike Campbell]

Thanks Kent.