I have a 1100 but really want a 18in barrel. I know I can cut one down. Than I found out that they have 18in V3. 1 never had a V3 in my hands. Are the barrels interchangeable? Thank you very much.

No interchangeability between the 1100 and V3. Check ebay. You can probably find a cheap non vent rib older fixed choke barrel you can cut down. I do not believe they made 1100 barrels shorter than 21".

I have an extra one cut. But thank you for the info