Help with Rem 870 Bayonet/+2 extension kit?

[Crazy Chaingun]

Hey folks, oping to get a little advice from S&J and/or the Gunnutz community.

Recently bought a bunch of upgrades for my new 870P, including an S&J jumbo safety (love it) and a combo +2 magazine extension and bayonet lug kit.

Also bought an Ontario Knife Co. M7 bayonet from another source, which I assumed should fit as any other AR-15 bayonet would. However as shown below, it appears that something is out of spec. The ring on the bayonet that should be connecting with the end of the magazine tube is sitting about a quarter inch too far forward. It clips into the lug at the pommel as it should, but without the ring supporting it at the front, it's barely held on.

Not sure if I've made a mistake of some kind with installing this? Or if the bayonet is out of spec? If the latter, what bayonets work well with these S&J setups? I have a line on an Eickhorn C7 bayonet, but I don't want to drop a considerable amount of money on it without knowing whether it'll fit my shotgun.

Any advice would be appreciated. For clarity - this is not a rip on S&J. I'm very pleased with the products I've bought (especially that safety). Just a little mystified at the bayonet issue...

[trudeau]

Move the support bracket back a quarter inch?

[Crazy Chaingun]

Move the support bracket back a quarter inch?

Unfortunately it's as far back as it'll go. Currently butting right up against the thicker part of the magazine extension.

[Jgoulin]

Could you flip it around? Or is the mount directly in the middle?

[Crazy Chaingun]

Could you flip it around? Or is the mount directly in the middle?

The front of the mount is sloped to allow the bayonet to slide on. Either way, the notch does look to be in the middle, so I don't think that would make a difference.

Anyone else with this same kit who's had luck with a different type of bayonet? Starting to think that the issue is the bayonet, not the installation or mount.

[Can-down]

What kind of extension is that? If it came as a package with the mount it should work, but it sure seems longer then a typical remington where it threads on.....?

[Crazy Chaingun]

What kind of extension is that? If it came as a package with the mount it should work, but it sure seems longer then a typical remington where it threads on.....?

It's this one here: https://www.sjhardware.com/product/8...mag-extension/

Only thing that wasn't part of the package was the bayonet itself. I should look up STANAG dimensions for the pommel-to-ring measurement and compare what I have to that.

[Battlerifleelitist]

Dremel that adapter and get it shifted back further.
It's redneck, but I think it's the only way to go.

Love bayonets

[Aniest]

Or if the bayonet is out of spec?

The muzzle ring diameter should be .880 inch for the M7, M9, M10, Stoner, OKC3S. Their hilt length (front face of crosspiece to rear face of pommel) should be 5 inches. I don't know if that helps you figure out lengths.

[badboybeeson]

good morning
as always email works best id you got it from us, just found this post.
it looks fro mthe photos you have a combo or our older mount ( it is longer front to back) and our +2 mag tube
to confirm that ill need you to tell me the size fro mthe frotn to the back. and ill check it against our newer units
again best to call or email us.
S&J