Remington 870 shell size question/concern

[leadcounsel]

As we all know, there are a variety of Remington 870 models (Wingmaster, Express, Express Magnum, Police, or simple "870").

There are a variety of sizes shells these take, which seem arbitrary too:
2.75, 3, and 3.5 inch shells.

The danger comes when the shell size is listed only on the barrel, and not on the receiver.

Can a larger capacity barrel be placed on a lower capacity receiver, and if so, is there a danger is the receiver failing as a result?

For instance, let's say a factory 870 is limited to 2.75" shells. But the barrel with that stamp is replaced with a barrel which accepts up to 3" shells, and 3" shells are used. Will it feed, and will the receiver be at risk of failing?

 

[Dreaming100Straight]

Yes. If you look at a barrel chambered for 3.5" shells, most, if not all, tell you not to use 3.5" unless the barrel is on a supermag receiver. Otherwise you may encounter extraction and ejection issues with the longer shells.

 

[jmr40]

The 3.5" receiver is different. You cannot make 3.5" shells work on any other gun.

If you have a receiver made for 2 3/4" shells it is possible to still use 3" shells as long as the barrel is made for 3" shells. The only real difference is the ejector which needs to be replaced. It wouldn't be dangerous, but ejection might not be reliable until modified.

The real danger is using 3" shells in a 2 3/4" chamber or 3.5" shells in a 3" chamber. They will fit. The marked length of shotgun shells is the length after they are fired. The unfired length is 1/4-1/2" shorter than marked. There has to be room for the crimp to unfold.

 

[Virginian]

The 3" and standard 2-3/4" guns are identical except for the ejector, ejector spring, and of course chamber length. Some standard guns actually left the factory with 3" ejector components anyway. If the barrel fits, you can safely shoot a shell the length of the chamber, but it may not eject properly. I do not think a fired 3-1/2" shell can be pried out of the smaller ejection port, but I can't say as I haven't tried it. Some people will say a 3-1/2" shell is not safe because of the higher SAAMI pressure levels, but I say the bolt locks into the barrel extension, and the receiver profile is the same, and it would be safe to fire, but as noted it won't eject properly. I also think if it wasn't safe Remington would have made it so a 3-1/2" barrel wouldn't physically fit, because they have to know someone is going to try it.