870 MK-1 trench attachment screws

[amac]

Does anyone know the size or have any idea where I could find some replacement screws ( 3 ) for this? I have the original attachment but no screws...any help would be much appreciated. Thanks

[Garden Valley]

Go here. http://www.customscrewsandmore.com/default.html

I had him replicate screws for me two or three years ago and he told me he kept the specs in case anyone needed screws. He does outstanding work.

[amac]

Thank you!

[Garden Valley]

You are welcome.

[mtrpdw]

I thrust the following info will be of use to you or someone else down the road:

There are actually three (3) different screw lengths used for the "Mk.1" type One-Piece and Two-Piece Clamping Sleeves, and the current Remington Magazine Extension Bracket/Clamp.

However, all use the same #12-24TPI threads, and all have the same slotted, semi-rounded head.

First photo:

Top: Remington manufactured Clamping Sleeve is the early, welded, One-Piece design. Screw length, measured from where the shaft meets the screw head, is 0.693".

Middle: Remington manufactured Clamping Sleeve is USMC Mk.1 Two-Piece design. Screw length: 1.057". This same screw is also used on the Two-Piece design with Bead Sight only.

Bottom: Remington Bracket/Clamp is basically the offspring of the Mk.1 Clamping Sleeves - introduced in the early 1970's and still produced today as part of the Remington M870 Magazine Extension Kit. Screw Length: 0.735".

2nd Photo:

Shows a close-up comparison of the three difference screw lengths: Left screw (0.735") - for current Remington Magazine Extension Kit Bracket; Middle screw (0.693") - for One-Piece Clamping Sleeve; and Right screw (1.057") - for Two-Piece Clamping Sleeve.

The current Magazine Extension Bracket (0.735") screws will work on the One-Piece Clamping Sleeve, no problem - just a touch short. These screws are readily available from Remington at around $4.50 each. However, they are too short for use on the Two-Piece Clamping Sleeve.