Problem with new barrel on 870

Wallabing · January 22, 2012, 06:06 AM

I put a brand spanking new 870 18.5 inch cylinder barrel on my 870 express.

Now however after a range session of 75 shells, there is excessive wear on the locking area of the barrel.

Lots of bluing has also worn off from my original bolt after I installed the new barrel, should I be worried?

James K · January 22, 2012, 01:10 PM

Were those 75 shells hot loads? It sounds like the gun had been fired mostly with light loads so the locking surfaces were never fully seated, and now they are. I wouldn't worry as long as the shells are not some kind of super hot handloads.

Jim

TheKlawMan · January 22, 2012, 01:54 PM

Wallabing, You say the bluing wore excessively in the locking area of your 870 Express. The Express isn't blued, but has someting similar to a Parjerized finish. I assume that is what you meant.

As for the wear, is it possibble that you didn't have the magazine cap tightened down (whatever you call the magazine cap) or it loosened up.

The 18.5" barrel has a spring loaded locking pin in the front of the barrel lug that allows the mag cap designed for it to lock down as cut outs along the edge of the cap ratchet down on the spring loaded pin. I assume that you are using the mag cap that came with an express equipped with a long barrel.

The long barrel cap may not catch on the detent pin of the short barrel. Still, if you haven't modified your Express detent system, which is done if you go to an extended magazine, I believe it would still catch on the cuts on the inside face of the cap that came with your Express.

Then again, it may merely be that you didn't tighten you mag cap enough when you put the barrel on.

I hope this is more helpful than confusing.

johnbt · January 24, 2012, 09:31 AM

It's a bead blasted finish with either bluing or some kind of black over it depending on the year. Mine is blued over the bead blasted metal, but it's a '93.

I'm inclined to think the wear is normal from what you've described.

zippy13 · January 24, 2012, 12:07 PM

Quote:

Lots of bluing has also worn off from my original bolt after I installed the new barrel, should I be worried?

Blue or black, you're probably going to see some finish wear on the mag tube, too. Not to worry, this is to be expected. If you're concerned about protecting your gun, there's a trick for 870/1100/11-87 users: Put a layer of grease where the barrel tang contacts the receiver. It will act as a cushion and distribute the load more uniformly.

Major Dave (retired) · January 24, 2012, 05:00 PM

changed my mind - will post my comments on a new thread

January 22, 2012, 06:06 AM	#1
Wallabing Senior Member Join Date: January 6, 2009 Posts: 113	Problem with new barrel on 870 I put a brand spanking new 870 18.5 inch cylinder barrel on my 870 express. Now however after a range session of 75 shells, there is excessive wear on the locking area of the barrel. Lots of bluing has also worn off from my original bolt after I installed the new barrel, should I be worried?

January 24, 2012, 05:00 PM	#6
Major Dave (retired) Senior Member Join Date: March 12, 2008 Location: Between Dallas and Shreveport, LA Posts: 569	A little off topic, but not much... changed my mind - will post my comments on a new thread __________________ Artillery lends dignity to what would otherwise be but a vulgar brawl.

January 22, 2012, 01:10 PM	#2
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Were those 75 shells hot loads? It sounds like the gun had been fired mostly with light loads so the locking surfaces were never fully seated, and now they are. I wouldn't worry as long as the shells are not some kind of super hot handloads. Jim

January 22, 2012, 01:54 PM	#3
TheKlawMan Junior member Join Date: June 23, 2009 Location: Orange County, CA Posts: 2,149	Wallabing, You say the bluing wore excessively in the locking area of your 870 Express. The Express isn't blued, but has someting similar to a Parjerized finish. I assume that is what you meant. As for the wear, is it possibble that you didn't have the magazine cap tightened down (whatever you call the magazine cap) or it loosened up. The 18.5" barrel has a spring loaded locking pin in the front of the barrel lug that allows the mag cap designed for it to lock down as cut outs along the edge of the cap ratchet down on the spring loaded pin. I assume that you are using the mag cap that came with an express equipped with a long barrel. The long barrel cap may not catch on the detent pin of the short barrel. Still, if you haven't modified your Express detent system, which is done if you go to an extended magazine, I believe it would still catch on the cuts on the inside face of the cap that came with your Express. Then again, it may merely be that you didn't tighten you mag cap enough when you put the barrel on. I hope this is more helpful than confusing.

January 24, 2012, 09:31 AM	#4
johnbt Senior Member Join Date: December 6, 1999 Location: Richmond, Virginia USA Posts: 6,004	It's a bead blasted finish with either bluing or some kind of black over it depending on the year. Mine is blued over the bead blasted metal, but it's a '93. I'm inclined to think the wear is normal from what you've described.