I'm back to 2 shotguns again, and one's an old Mossberg bolt-action 20 gauge with external choke tubes. It was my mom's gun when she hunted, which was so long ago, it was probably before I was born. My dad said one time she shot at a bird with it and missed. He heard her empty the gun, and she fired all 3 shots so fast it sounded like she had a semi-auto. I don't remember ever seeing my mom shoot any kind of gun, so it really sounded strange hearing about it. I bought a bunch of slugs and some buckshot for it. I planned on mounting a scope on it and using it as a slug gun with the the IC choke, and possibly getting the barrel modified to use a rifled choke tube. Then I found out no one makes a scope mount for it, and it's been setting here waiting for a custom mount to be installed ever since.
My dad had a 20 gauge Remington Sportsman 58, which was a near twin of his Remington Woodsmaster Model 740 .30-06. The Model 58 was Remington's first gas operated shotgun, and the direct ancestor of the Model 1100. The gas system and the action spring was was built into the front end of the magazine tube. So that limited the capacity of the magazine tube to two shells. Gas was tapped from a hole in the barrel into a large chamber. A piston in the chamber drove an action bar rearward which, in turn, operated the bolt to cycle the action. They were making the long-recoil operated Model 11-48 semi-automatic shotgun, based on the Model 11 at the same time, but the Model 58 was more expensive to make than the Model 11-48, and was less reliable and heavier. Remington chose to replace the Model 58 with a model that combined its best features with those of the Model 11-48. The resulting Model 1100 immediately replaced the Model 58 and proved so successful that it soon also replaced the Model 11-48.