remington model 11

[tankerman]

any military markings?

[Shrubmaster]

Looks like you may have a crack in the foregrip too. The model 11 is a close cousin of the browning a5. The foregrips are swapable if you do find that you need one. Ramline makes a synthetic for the A5 that I heard swaps over but the stock needs some modification. Unfortunately not all the parts swap over but some can be modified to fit. Barrels are not swapable but I heard that the savage 720 shares the same barrel as the model 11. I have a couple A5s and just recently purchased a "military finish" WW2 model 11 flamimg bomb marked(still in jail). Great shotguns though. Bonnie and Clyde favored the model 11 that was cut down. I would go through and replace all the springs and friction rings before shooting. Worn springs can cause the bolt to bottom out on the receiver thus cracking the bolt which isn't uncommon to happen. Also make sure that you have your recoil settings set right(look up the settings for an A5). Shooting heavy loads and having the recoil settings set for light can also result in a cracked bolt. This is what usually caused the issues I believe. Before putting any effort into refinishing it, Go through and inspect it and see what damage is done. Once you feel confident that it is shootable, replace the old springs and give it a really good oiling/cleaning. Shoot it. If it shoots good then look into getting her polished up nice. I have only shot A5s so far and they are wonderful shotguns. In fact, for a 100+ year old design, they were rereleased this year.
Kevin

Everything he said.

Might make a great trench gun copy too

[Sicarius]

The 870 magazine extension has the same threads so you can make a great HD/tactical/IPSC gun out of it. You may need a 1/8th spacer depending on which company you go with for the extension. Some actually make ones specifically for the A5 which will bolt right up.You can also replace the carrier with a 2 piece A5 carrier with a little modification to take advantage of the auto chambering feature of the A5(2 piece carrier). The A5 is still to this day, the fastest reloading shotgun from an empty chamber with the bolt locked back.
Kevin

[gun toting monkeyboy]

It didn't say because in all likelihood, 3" shells didn't exist. It may very well chamber them, but that doesn't mean it is safe to use them. You have an older, beat-up shotgun. Why on earth would you run 3" shells through it in the first place? Clean the whole thing up. If the pits on the barrel aren't too deep, it will shoot 2 3/4 inch shells just fine. Swap out any older springs just to improve it's function, lube it up, and go have fun.

-Mb

[Sicarius]

I don't think the recoil system is made to handle it to begin with even if it does chamber a 3 inch shell. It may not eject the shell at best and probably wreck the bolt by bottoming it out.
Kevin