The magazine capacity restriction "plug" is removed in a similar manner for most all pump action or semi-auto shotguns. Remington shotguns are quite easy to remove. At the very front end of the magazine tube you will find a screw-on end cap. Remove this end cap and you should notice a cap that has been pushed into the magazine tube. This cap is friction fit into the tube and under pressure from the magazine follower spring so put a pair of safety glasses on your face before you begin removal. This cap usually has a hole in the center of it. Use a flat blade screw driver to carefully pry this internal cap out the front end of the magazine tube using the hole in the center of the internal cap. Be careful as this spring is under pressure and may come flying out rather quickly. Once the internal cap is removed the spring will relax and grow in length considerably. The restriction plug is captured inside this spring. Remove the plug and start pushing the magazine follower spring back into the tube. Once you get the spring almost all the way back into the mag. tube, put the internal end cap back in and gently tap it into the tube with the back end (plastic handle) of the flat blade screw driver. Push this internal cap in until it is flush of just below flush with the end of the tube. Replace the forearm and screw-on cap and go have a beer.
Read the owner's manual or have a gunsmith do it.
Take the cap off and point the gun doun and shake it and it should come out mine did
Standard 16 gauge shotgun shells.
Take it to a qualified gunsmith
Take it to a gunsmith.
How many cartridge does a 12 gauge shotgun carry.
Remove the barrel and then unscrew the magazine tube from the receiver.If the mag tube is too tight to remove easily, use pliers or visegrips ONLY on the very last inch of the tube where the barrel screwed in. It's the only solid part on the tube and it won't bend or crush.
Take it to a gun smith.
You take it to a gunsmith
To determine exact value of a 1904 Marlin 12 gauge pump shotgun, you would actually have to take a number of factors into consideration. The main thing to consider would be the condition of the shotgun.
Gun is restricted to 3 rounds by design. It has no mag plug, that is where the gas system is.
If you don't have an owner's manual, take it to a gunsmith