Rifled barrel/Screw modifier

I’m trying to make a gun, and almost immediately I’m being flummoxed by the rifling in the barrel. I added a circle, extruded a few bumps on the inside for the grooves, then applied a screw modifier, but the screw mod is pinching and distorting the circle.

I’m very new to blender, so is there something I’m doing wrong with the screw mod or is there a better way to do this? I’ve tried extruding the full length of the barrel and then twisting it, but then the middle gets pinched in.

I’m sure this is an easy fix, but like I said I’m brand new. Any suggestions would be appreciated.

Try proportional editing.
You will need to add some loop cuts, inside and out. Then select the very end verts and then enable proportional editing and set it to root. Then rotate the selected verts expanding the “effect sphere”(i dont know what its called), so it effects the entire tube.


barrell.blend (557 KB)

Well, I couldn’t figure out what you did with the file you provided, but I took your advice and subdivided my barrel into 6 sections and rotated each one increments of 15 degrees. That seems to look ok. Wouldn’t work on a real barrel since it still pinches very slightly in each section, but it looks good enough, and this is just something I’m rendering out for a comic, not throwing out to a 3D printer or anything. Assuming I can figure out a good outline render that is.

Thanks for the help.