Thanks both for the sound advice. I tried a little more force, as much as I dared, and still the bolt wouldn't close. Next step will be to fire the round in the 30-S and see if the spent cartridge will chamber in the Zi-Di. The ammo is vintage Remington Core-Lokt with 117 gr round nose. Maybe the Zi-Di will like a different bullet. It's a sweet little cartridge by the way. Should be great for turkey and other critters up to whitetail deer. I'd now like to have one of the Remington pumps in this chambering and am researching what other factory rifles were built in .25 remington.