LEO® Telescoping Stock Adapter for Beretta 1301 (12-GA)

Our aluminum adapter kits include everything necessary to retrofit Beretta 1301 semi-automatic shotguns with most AR-15 style stocks and pistol grips. Our adapter kits allow customers to add their own AR-15 stock assemblies as desired. The optional recoil buffer can absorb felt recoil by up to 70%.

SKU: 91050


System Concept and Product Overview

The most important capability of these adapters is to facilitate the use of collapsing or telescoping stocks, which provide a shorter length of pull (LoP) than the factory stock, which is especially important for law enforcement or “tactical” operators. In addition, these stock adapters accept a hydraulic buffer from Crosshair™ that reduces felt recoil. The Mesa Tactical/Crosshair combination is by far the most robust and most effective of several recoil-reducing shotgun stock systems on the market.

LEO® telescoping stock adapters, which feature a stock elevation about an inch lower than the High-tube adapters and so don’t require sighting or aiming aids.

These adapters are available in two types of kits, adapter kits or complete stock kits.

The concept is simple: the shotgun stock is replaced by an adapter that mimics the stock attachment point of an AR-15 lower receiver. This adapter accepts an AR-15 receiver buffer tube. The AR-15 collapsible stock and pistol grip can then be reliably attached to the shotgun. 

Stock kits additionally include an M4 Carbine style telescoping buttstock assembly, a Hogue rubber overmolded pistol grip, a stamped steel stock wrench and a push-button sling swivel. A slip-on rubber butt pad for the M4 Carbine buttstock is available separately.

All LEO adapters accept optional push-button sling swivels.

Shotgun Platform Compatibility

The Telescoping stock adapter Shotgun Conversion Kits are available for the following 12 gauge and 20 gauge pump-shotgun platforms:

Remington 870
Mossberg 500, 590

Generally, Mesa Tactical telescoping stock adapters will not fit on semi-automatic shotguns. Most semi-automatic shotguns feature a return spring housing that extends from the rear of the shotgun receiver that makes it impossible to fit an AR-15 stock system to the weapon.

Stock and Grip Compatibility

The Mesa Tactical LEO telescoping stock adapters can accept AR-15 stocks that do not require a lower indexing dimple. This includes most military and commercial collapsing stocks, but few if any fixed stocks. Generally, any stock with an indexing groove machined into the ventral side of the receiver extension tube threads will work with the LEO Telescoping stock adapter. Other stocks may be installed with minor fitting.

Similarly, the Mesa Tactical LEO telescoping stock adapters can accept any grip that does not feature a rear upper extension.

Recoil Buffer Kits

Mesa Tactical Recoil stock kits include a Crosshair™ recoil buffer assembly instead of the hollow receiver extension tube. The recoil buffer can absorb felt recoil. Install the recoil buffer according to the instructions below, just as if it was a receiver extension tube.

WARNING: The Crosshair buffer is spring loaded. Do not disassemble or serious personal injury or death could result.

WARNING: During firing the Crosshair buffer compresses up to ¾” as the shotgun moves rearward. DO NOT place eyes, hands or cheeks close to the grip of the stock adapter. Keep face and other body parts at least 2” from the threaded end of the Crosshair buffer.

Package Contents

The Mesa Tactical Telescoping Stock Adapter Shotgun Conversion Kit should include the following components:

  • 1 “Double-headed” flush cup
  • 1 “Double-headed” flush cup mounting screw
  • 1 “Double-headed” flush cup hex key
  • 1 Pocket grip nut

Assembly of the Mesa Tactical Telescoping Stock Adapter Shotgun Conversion Kit requires no special tools and should take less than 30 minutes. All required hex keys and an AR-15 stock wrench are included with the stock kit. All you will need to provide is a Phillips head screwdriver (for the pistol grip), plus whatever tools are required to remove the old stock (an AR-15 stock wrench and stock nut is not included with the stock adapter kit, only with the complete stock kit).

Optionally, you might want blue Loctite® liquid thread locker for the screw threads. A torque wrench is also useful to ensure you are using the appropriate torque settings on the fasteners.

For assembly instructions (click here)


LEO stock adapters accept most third-party AR-15 stocks or pistol grips.

*The following items cannot be exported without a license

Stock kits include push-button sling swivels.


All Mesa Tactical products are made in the USA of high quality materials and include LIFETIME WARRANTY.Mesa Tactical warrants that all products are free from defective material and  workmanship and, subject to the conditions set forth below, agrees to repair or  replace any part of a product that proves defective by reason of improper workmanship or materials without charge for parts and labor. In no event will Mesa Tactical be liable for damages, lost revenue, lost wages, lost savings or any other incidental or consequential damages arising from purchase, use or inability to use this product. No express or implied warranty is madefor Mesa Tactical product damaged by accidents, misuse, natural or personal disaster, or any unauthorized disassembly, repair or modification. Mesa Tactical’s warranty covers only repair or replacement of defective Mesa Tactical products. 

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