As noted above, the problem with the 3" chambered barrels is they have smaller gas ports and most won't cycle cheap target loads. It's a quick fix to drill out the gas ports, or buy a spare 2 3/4" barrel.
The 303's are definitely worth buying as they are one of the smoothest and softest shooting semi auto shotguns ever built.
If I run into a 2 3/4 I will consider it .
