I’ve never had any trouble using standard-size loads in a 3.5" chamber. I usually shoot 2¾" shells since they’re more affordable, gentler on the shoulder, and do the job just fine for what I’m after. I think the only bad thing I observed is that some 3.5" semi-autos can be a bit picky with really light target loads. My old turkey gun, for example, just couldn’t stand those super-soft Walmart bulk packs.