Video | What’s Included | Specs | Pictures | FAQ | Related Info

If you carry a rifle with you every day, whether off-body in a pack or in your vehicle, it’s not a bad idea to carry a spare rifle mag on you. This rifle mag attachment for the new Sidecar holster lets you do just that.

Attached via the Spine System with a Spine pin and friction washer, it can carry a variety of 5.56 STANAG magazines in the appendix position, rounds facing rearward or forward depending on user preference. Because the new Sidecar is hinged, the rifle mag remains very well concealed even when running higher capacity mags like 40 round PMAGs. Some retention adjustments will be necessary to fit the brand of magazines you choose to carry. Watch the overview video for a breakdown of installation and adjustment.


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One T.REX Sidecar Rifle Mag Attachment with one T.REX IWB Tuckable Clip installed.

Note: Does NOT come with a rifle magazine.

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  • Made from 0.093 precision-formed Kydex.
  • Has four screws for retention adjustment. Because of the adjustable retention, we’re confident it will fit the vast majority of standard STANAG 5.56 magazines. We’ve tried PMAGs, Lancer Mags, steel HK mags, and old-school aluminum mags.
  • Comes set up for right-handed carry but you can easily swap the Tuckable Clip to the other side of the carrier to run it on your left-handed holster.
  • The attachment and Spine are formed from a single piece of Kydex for a smooth and flexible design. The attachment is connected to the holster by a machined steel pin, which lends the Spine strength and creates the ability to quickly and easily swap out attachments.
  • Made in the USA by T.REX ARMS.

View the Sidecar Hardware Diagram HERE.

The T.REX IWB Tuckable Clip is injection molded from high-strength acetal plastic. It is 3/4″ wide and 3 5/8″ long and is a Universal fit (i.e. fits belts 1.5″ to 1.75″) with a 0.5″ of adjustment. Made in the USA.

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What is the purpose of this? Why would I ever want to carry a rifle mag attached to a pistol holster?
For the same reason we recommend everyone who carries a pistol also carries a spare pistol mag on their person, we recommend if you carry a rifle regularly you should also carry a spare mag on your person. Pistol mags are easier to carry in pockets, especially with tools such as the NeoMag, so storing a spare rifle mag attached to your Sidecar can be a comfortable, concealable, and effective option. This is especially true for those that work in environments that require they have a rifle, but still want to maintain low visibility.
Does this have to be attached to a Sidecar holster? Can it be used by itself?
While it is possible to wear this carrier by itself, we don’t recommend it. It’s not as stable worn alone as when attached to the Sidecar holster. Trying to wear this by itself with just a single clip holding onto your belt will create an inconsistent angle as it twists in your beltline. If you are adamant about wanting to run this alone, add a Raptor Wing + Clip to give it some stability and consistency.
Could I attach this to a Sidecar without the friction washer?
The question isn’t really could you, but should you. While the Spine pin is very secure even without the friction washer, it’s wise to build in redundancy. If you need replacement hardware, you can find it here.

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Sidecar Rifle Mag Attachment Overview – Video – T.REX ARMS

The New Sidecar Holster Overview – Video – T.REX ARMS

The Open Source Sidecar Spine System – T.REX ARMS

The Open Source Sidecar Spine System – Video – T.REX ARMS

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