My usual method for a strong yet easily rotated to remove arm join, rod magnet 8mm diameter by 30mm. Ample pull to keep firmly in place.
I love the thought out design of this piece, the barrel rotating mechanism on the lower left, the ejection port for spent casings underneath.
A close up of the barrel rotating mechanism shows it actually has a cog for rotating the gearing mesh of the round cylinder.
What's more is the rotating assembly is the ideal hiding place for the resin vent of the cylinder piece - great design!
The ammo hopper
The two armoured cowlings can be left off to paint last, a great design too.
The feed tube from the ammo hopper goes into the gun assembly, where I can see a piston assembly rams the shell into the breach of an emply barrel, it rotates clockwise, fires at the bottom of the arc and ejects the spent casing underneath, using the upswing to swab, cool etc the returning barrels ready for the next load.A size comparison from the Battle Titan Gatling Blaster, I hope these are made Warlord Carapace option too, like in Adeptus Titanicus, otherwise I will have to convert two of these into shoulder mounts.
Box o' resin joy.