7 Or 8 Shot
Magazine
Extension
Instructions

Part#SMR-0700
(Remington 7rd)
Part#SMW-0800
(Winchester 7rd)
Part#SMR-0900
(Remington 8rd)
Part#SMW-1000
(Winchester 8rd)

MAKE SURE YOUR SHOTGUN IS UNLOADED
BEFORE STARTING!

Minimum barrel-length for 7-shot extension is 18 1/2".
For 18.5 inch barrels use the 7-shot extension.

Minimum barrel-length for 8-shot extension is 20".
For 20+ inch barrels use the 8-shot extension.

1) Unscrew the magazine cap and remove.

2) Remove the magazine spring retaining cap.

CAUTION: The spring is under tension and will shoot out of the mag tube.

NOTE: Some new Remington shotguns use a plastic cap retained by an indentation in the magazine tube. To remove, use a flat blade screwdriver in the cap slot, press inward and rotate 1/4 turn in either direction to release. (Before installing the new spring, the indentation must be flattened with either a half-round file or a Dremel tool.)

3) Remove the spring from the magazine tube and leave the shell follower inside. Place the new spring into the magazine tube (filed flat where necessary). Place the magazine extension over the end of the spring, compress toward the tube and tighten.

4) RECOMMENDED: Advanced Technology, Inc’s Barrel Magazine Clamp with sling swivel stud should be used with the magazine extension. The clamp strengthens the magazine’s connection and enhances appearance. Attach a sling using the sling swivel stud.