Carbon Fibre 12g Shotgun Magazine Extension Tubes

2026-02-10T14:57:12+00:00

Price: 119.99

Extremely Light Weight – 73g for a 500mm (+8rd) tube

High Strength Carbon Fibre

Impact-Resistant Polymer

These carbon 12g shotgun magazine extensions are designed to shed weight from the place it affects you the most, resulting in faster transitions and easier gun manipulation by lowering the moving mass. Just 73g on a 500mm tube.

Note: The extension tube will add to the internal standard capacity of the gun; for instance, a Benelli M2 has an internal capacity of 4 rounds, and a +6 extension tube will give 10 rounds total in the magazine tube.

High spec carbon fibre made to our specification with a premium matte finish. The one piece carbon magazine is bonded using cutting edge adhesives used in the automotive industry for sports car chassis.

To calculate the number of rounds, count 60mm per round and +30mm for the spring and follower. For example, for a +8rd tube, you need 8 x 60mm (480mm) plus 30mm which is 510mm. Cut tolerance is +/- 2mm.

For reference, a Beretta 1301 has a standard internal capacity (without an extension tube) of 5, and the Benelli M2 (all variants) has a standard internal capacity of 4. The total capacity of the gun would be the standard internal capacity plus the extension's capacity. For example, if you would like your Beretta 1301 to have a total capacity of 10 you would need a +5 tube. All known standard internal capacities are listed below.

Benelli M2 (all variants) - 4 rounds

Benelli M4 - 5 or 7 rounds (depending on variant)

Benelli Nova - 5 rounds

Benelli Nova SPEED - 5 rounds

Benelli Supernova - 5 rounds

Beretta 1301/Tactical - 5 rounds

Breda B12i - 4 rounds

Mossberg 940 / 930 - 4 rounds

Mossberg 590 - 6-8 rounds

Stoeger M3000 / M3K - 5 rounds

Remington 870 - 4 rounds

For any help or recommendations, please don’t hesitate to get in touch using the Contact Us form.

For example, if you wanted an extended shotgun magazine to take your Beretta 1301 Tactical from 5 shell capacity to an extended 7 rounds, you should select a +2 cartridge magazine tube. Magazine spring is sold separately here.

NOTE: 2-3 weeks for delivery, each tube is made to order! Please read the specifications above. As these are custom tubes, we will not be able to accept returns.