Special thanks to Tactical887 for this review of the new ATI 7 Shot Fluted Magazine Extension.

The new ATI 7 shot fluted magazine extension, is not just all about aesthetics. It is constructed of military type 3 anodized, 6061 T6 aluminum. The standoff cap is designed for breaching doors, however the 7 shot extension runs fairly flush with the bore of an 18.5” barrel (see the first picture below).

New ATI 7 Shot Fluted Magazine Extension

New ATI 7 Shot Fluted Magazine Extension

If one were anticipating to use this extension as a breaching tool, then I would recommend you purchase the 8 shot extension. The 8 shot extension will protrude past the bore further than the 7 shot, making it easier to jam into door wedges. ATI makes an assortment of different end caps. If the standoff end cap (shown in the picture above) is not your style, ATI makes plain and swivel stud end caps.

New ATI 7 Shot Fluted Magazine Extension for Remington 870

New ATI 7 Shot Fluted Magazine Extension for Remington 870

ATI, incorporated a ratchet base for a tight fit. This is a nice feature because there is no need for magazine clamp, commonly found on the factory Remington 7 shot extension. I have fired about 100 rounds through my 870 with the new ATI 7 shot fluted magazine extension, and it did not loosen from the recoil.

Another advantage is that the extension runs flush with the shotgun barrel lug (see picture below). This gives the 870 a mean but yet unified look, the barrel lug would also supply extra support to the extension during the breaching process.

New ATI 7 Shot Fluted Magazine Extension for Remington 870

New ATI 7 Shot Fluted Magazine Extension for Remington 870

The advantages of the new ATI 7 shot fluted magazine compared to the Remington factory 7 shot magazine extension are like night and day.

Cons of the Remington 7 shot magazine extension:
A magazine clamp is needed in order to keep the extension from coming lose during recoil. The magazine clamp will scratch the barrel as well as the extension upon removal and reassembly. The magazine clamp is added weight and prolongs take down time.

The bayonet mount creates a smaller internal diameter which shortens the magazine spring and creates more tension, only allowing for six 2 ¾” shot shells to be loaded in the magazine tube and one in the chamber. Technically making the 870 have a 6+1 capacity. But when you think about it, it really is only a 6 shot extension even though it’s marketed as a 7.

Pros of the ATI 7 shot fluted magazine extension in regards to the Remington factory mag ext.
No magazine clamp
Military type 3 anodized, 6061 T6 aluminum construction
Fast take down time
Allows the magazine spring to have proper tension, the magazine tube will hold seven 2 ¾” shot shells and one in the chamber for a total of a 7+1 capacity.

on the right is the Remington factory 7 shot magazine extension

on the right is the Remington factory 7 shot magazine extension

ATI is stepping up their quality and their attention to detail. The new ATI 7 shot fluted magazine extension, comes in a nice foam padded box. At the bottom of the box are the installation instructions and the 7 shot magazine spring. For the small price of $50.00, with 2nd day shipping and $50.00 insurance, you can expect this magazine extension to arrive quickly. ATI has changed their designs, quality, packaging, 2nd day shipping with insurance and customer service, to provide a better experience for the consumer. With all the specifications I have listed above in mind, the new ATI 7 shot fluted magazine extension is a fantastic choice and a great addition to any Remington 870.

This magazine extension was discontinued by the manufacturer and no longer available.