Thanks for the explaining what's happening Michael.

Of course I created the barrel and performed the fillet and mirror first before the boolean with the ship hull but yes, I see that the result did shorten the rear side as you have shown.

Thinking a bit, perhaps it might be easier if instead of attempting to create a complete model in MOI, I can use it to create subassemblies which I can piece together back in my poly app, hmmm...

I'd still have to be careful how I create the individual parts though!

While more work, hopefully it would be less work than trying to repair the whole model as I attempted before.

It's just looking at that model, it just seems like something you'd totally want to create in MOI! (And of course you can, it's just the resultant topology is not going to be game engine friendly!)

-Will