Slugs out of pellet rifle, general starting point ??'s

My Maverick VP in 25 cal shoots great with my 34 grain JSB's at 895 fps using the stock Superior liner.
I have absolutely no need to shoot slugs. But I want to try some just for fun without changing my tune. If they don't shoot accurately so be it.
That being said, with this barrel, would you slug guys suggest starting with lighter slugs, say 27 or 29 grain, or go heavier than my 34 grain pellets?
I'm not looking to become a slug shooter but just want to try for no other reason than that I can. lol