I would think about this before slugging it out with your fine ss.

No rifled sight set up so accuracy is going to be a crap shoot, period. You say that you wing, trap and action shoot the ss "very well", but keep in mind there is alot of help from the fact that the shot spreads out and a slug can only "spread out" (expand) once it hits the meat and only really if it's designed to.

That covers the "performance" potential. Now for the mechanical drawback I envision. I may be wrong, and anyone feel free to correct me cause I am by no means an "authority".

Those doubles (especially nice over and unders) are designed for light weight for fast handling, etc.... Therefore the most weight trimming is going to be in the barrels. I imagine that these barrels are designed with the expectation of blasting terget load and other type of shot loads which do not exert high pressure levels in the barrel. Now on the subject of slugs, these are propelled by a much higher pressure level and will probobly only help to deteriorate your barrels future performance.

Just my thoughts.