I just bought 3" rem. hi velocity magnums for my rem. 870 express 12 gauge pump. When I looked at the barrel of my gun it read "

[pjsabella]

I just bought 3" rem. hi velocity magnums for my rem. 870 express 12 gauge pump. When I looked at the barrel of my gun it read "use 2 3/4" or 3" shells in magnum receiver, use only 2 3/4" in all others." What does this mean? Can I shoot my 3" magnums in this barrel or should I just shoot 2 3/4"?

[DSMbirddog]

I haven't looked at any new 870's but in the past it said Magnum on the receiver. Your barrel is okay for 3" Magnums.

[Kody]

I have an assortment of Rem 870 barrels in different chokes for guns of my own and those past down to me from different relations. I believe it is possible to install the old Remington 3 inch mag barrel onto the 'receiver' of a 2 3/4 inch 870 Remington shotgun. NOT A GOOD IDEA! Exercise some caution here as you may be messing with real danger. Perhaps I am mistaken in this matter, but the old adage about stupid questions as opposed to stupid mistakes would apply here. If your receiver is open to debate compare it to a 870 clearly labeled on its RECEIVER to be a 3 inch magnum to make sure you are on the same page. Still uncertain check with a gun smith.

[Dcast]

No you should not shoot magnums out of an express that the receiver isn't marked for magnum loads. The barrel can handle magnum loads but the receiver cannot.

[PigHunter]

If that is the original barrel that came with the new 870, then you can use 3-inch shells. The warning is there because the 870 barrels are interchangeable and can be placed on older models not tested for those pressures. When in doubt, contact Remington with the Serial number off your receiver and ask them.

From the Remington web site:

I bought a used gun and I want to make certain that it is safe to use. What should I do?

Whenever you acquire a used firearm you should have the firearm checked out by a Remington Authorized Repair Center or qualified gunsmith BEFORE YOU USE IT. Additionally you could send it back to us at the factory and we would be glad to look at it for you:

Remington Arms Co., Inc.
Attn: Arms Service Division - TPA
14 Hoefler Avenue
Ilion, NY 13357

Please fill out the repair form from the Repair Services page and include it with the firearms when you send it back to us.

NOTE: Remind other gun owners that they should have their guns checked out periodically by a qualified gunsmith.

NOTE: An obsolete gun may not be repairable.

[PigHunter]

I have an assortment of Rem 870 barrels in different chokes for guns of my own and those past down to me from different relations. I believe it is possible to install the old Remington 3 inch mag barrel onto the 'receiver' of a 2 3/4 inch 870 Remington shotgun. NOT A GOOD IDEA! Exercise some caution here as you may be messing with real danger. Perhaps I am mistaken in this matter, but the old adage about stupid questions as opposed to stupid mistakes would apply here. If your receiver is open to debate compare it to a 870 clearly labeled on its RECEIVER to be a 3 inch magnum to make sure you are on the same page. Still uncertain check with a gun smith.

Great answer!