Yes, but you will get better results with improved or cylinder bore.
At 16 yards, probably the improved modified choke in a 30 inch bbl is the most commonly used
Yes, you can shoot 2 1/2,2 3/4, and 3 inch shot gun shell in that barrel.
You have a Baikal Model IJ-18 that was imported from the Soviet Union. If it has a 26 inch barrel it has no choke, a 28 inch barrel has a modified choke, and the 30 inch has a full choke. It is worth about $100 in excellent shape.
Yes, a Remington 1100 with a 30-inch full choke barrel can be used to shoot steel shot, but caution is advised. Full choke barrels may not perform well with steel shot, which can lead to increased pressure and potential damage to the barrel. It's generally recommended to use an improved cylinder or modified choke for steel shot to ensure safe and reliable performance. Always check the manufacturer's guidelines and consult with a knowledgeable gunsmith if unsure.
Yes, you may shoot slugs or buckshot through a shotgun fitted with the C-Lect Choke system. This is from the tag that Mossberg attaches to their shotguns fitted with C-Lect Chokes.
Full choke for all buck shot.
There is no "Standard" choke. A5's could be purchased with one of many different chokes, however, the more common chokes on a 28" barrel were Full and Modified
80-120 depending on condition. I just bought one for 60
The 12 g Marlin 200 single shot shotgun SHOULD be marked on the barrel, something like "model 200 12 g 3" Modified" That means it will fire the 3 inch magnum shotshell, and has a modified choke. If you have a shotgun marked 2 3/4, do NOT fire a 3 inch magnum, even if it will chamber. The forcing cone will not have enough length for the shell to open, and it will cause unsafe high pressures. Every 200 I have seen (a limited number) WAS chambered for 3 inch Magnum shells.
80-120 depending on condition. I just bought one for 60
In general, no. Unless the gun is marked for 3 inch (or even 3 1/2 inch) shells, you should not attempt to fire 3 inch Magnum shells, even if they seem to fit. However, if you have a gun made for 2 3/4 inch shells, and have 2 3/4 inch "magnum" shells, IF your gun is safe to shoot, it should be safe to shoot those "baby" magnums.
The last one I saw today had a 28 inch full choke barrel. Sure I would shoot buckshot out of that shotgun all day. I don't know about slugs though. The box of slugs state that they will shoot out of any choke; however, IC produces the best results.