yes you can use 3 inch and SHORTER 12 ga shells with no issues

Dennis, the CD 601 has a 3" chamber, so it will shoot both 3" and 2 3/4" inch shells. Have a great day!

Dennis, it sure will. The charles daly 601 combo has a 3 inch chamber so it can safely fire 2-3/4 inch and 3 inch shells. Since it's a semi automatic shotgun I'd recommend high velocity 2-3/4 inch shells atleast for the first 100 rounds or so until it's broke in. Low velocity rounds might not completely cycle the bolt causing it to jam until the bolt smooths out. Hope this helps.

Dennis, yes Sir. This shotgun has a 3 inch chamber, it can fire 3 inch and shorter 12 gauge shells (2 3/4) no issue. It is recommended to break it in with high power shells (50 or so) initially and then clean and re-lube.