FAQ: Mesa Tactical Telescoping Stock Adapters and Kits

Telescoping Stock Adapters and Kits

Why do I need a telescoping stock on my shotgun?

Tactical shotguns are not like baseball caps; one size doesn’t fit all!

Your shotgun’s factory stock, essentially a fowling arm stock, is probably already too long for tactical applications. In addition to being adjustable to fit the size and stature of the shooter, the telescoping stock’s easily adjusted length of pull (LoP) is even more desirable with the increased popularity of body armor and heavier tactical clothing.

Why is it an AR-15 style telescoping stock?

The AR-15 has in recent years become one of the most popular rifle platforms in America, with many accessories, including stocks, available from a large number of suppliers. Developing an adapter to accept the AR-15 telescoping stock was simply the simplest way to add this capability to a shotgun, and provides the operator with the most flexibility.

Is the AR-15 telescoping stock strong enough for use with shotguns?

Absolutely. After five years of sales we are not aware of a single failure in the receiver extension tube, nylon buttstock or grip (the AR-15 components of the stock) due to the more severe shotgun recoil.

However, as the AR-15 buttstocks were never designed for comfortable use with shotguns, we always recommend the fitting of a rubber buttpad to temper the hard plastic and sharp edges of the buttstock.

What does the stock adapter do?

To fit an AR-15 stock and grip to a shotgun, some sort of adapter is required to replace the factory stock. Basically, this adapter looks like a factory stock where it faces the shotgun receiver, and accepts an AR-15 stock and an AR-15 grip at the rear and bottom.

What’s so great about the Mesa Tactical stock adapters?

The most important difference between the Mesa Tactical stock adapters and many others on the market is ours are made of cast aluminum instead of plastic. A metal adapter is stronger and more reliable, and better able to withstand the hard use common in law enforcement environments.

Almost all our products are made for law enforcement or other professional operators, and so are meant to take more abuse than the typical gun show bargain accessory.

Why do you have three different lines of stock adapters?

First, some history. The High-tube telescoping stock adapters were our first products, and were designed to feel exactly like an AR-15. We also thought it would be a good idea to machine in some accessory mounting points on the sides of the adapters, in case operators would want to mount sling attachments or shell carriers onto the adapter rather than the receiver.

But in making the stock set-up exactly like an AR-15, the stock elevation was too high to be used without an optics rail, so we came out with the Low-tube adapters that could be used with iron sights or even the bead sight. We retained the side mounting points on our Low-tube adapters.

Those side mounting points, we discovered, were almost never used by any of our customers, and they made the adapters more difficult and expensive to machine, and thus more costly in the market. So we next introduced the LEO adapters which share the same dimensions with the Low-tube adapters, but simply do not have those expensive (and largely useless) mount points. They are cleaner looking and cost less.

How do I know if I need an LEO, Low-tube, or High-tube stock kit?

Generally, you will want an LEO adapter or stock kit, but let’s run through the different lines:

The LEO Telescoping Stock Kit We introduced LEO Stock Kits for the Remington 870 in January 2007 as more streamlined and economical versions of our Low-tube Stock Kits. LEO stands for “Law Enforcement Officer,” as we were trying to get to a price point more attractive to police department bean counters, but they are available to anyone. In early 2009, we introduced an LEO adapter for the Mossberg 500.

The LEO adapters are sleek, reliable aluminum stock adapters that cost less than the Low-tube adapters because they feature far less machining, not because there is any difference in quality. The stock elevation is very near to that of a factory stock, and steel inserts that accept push-button sling swivels are installed at the factory. We will normally recommend the LEO stock kit for almost all applications. The Low-tube Telescoping Stock Kit

Low-tube Telescoping Stock Kit We introduced our Low-tube Stock Kit in January 2005 to allow the use of AR-15 telescoping stocks on shotguns with conventional receiver-mounted iron sights, such as ghost rings, tilt-ups, or even the original bead sight. The receiver extension tube is about and inch lower than the High-tube design, and the cheek weld is about the same height as factory stock.

The Low-tube stock adapters feature accessory mount points just like the High-tube adapters. Because these mount points are so rarely used by our customers, the Low-tube stock adapters are basically replaced for most practical purposes by our less expensive LEO adapters. But they remain in production because a number of large agencies continue to order them, it being difficult for them to change the part numbers on their purchase orders after certifying the Low-tube adapters.

The High-tube Telescoping Stock Kit High-tube Telescoping Stock KitOur High-tube Stock Kit is designed to mimic the dimensional relationship between the telescoping stock, pistol grip, and top rail of a flattop AR-15. The receiver extension tube is almost concentric with the bore of the shotgun, resulting in a high cheek weld, which is higher than is typically found with standard tactical shotguns. This makes it possible to use rail-mounted optics, such as a red dot sight, to achieve correct sighting geometry. All true AR-15 stocks can be supported with this configuration, and it is certainly easier to switch back and forth between an AR-15 and a tactical shotgun if the shotgun is dimensionally similar to the AR-15.

Unfortunately, the High-tube adapters cannot be used without a Picatinny rail and rail-mounted optics or other sighting system. Therefore it is only ever sold with a rail (which mounts to the top of the adapter). This makes the High-tube stock kit expensive and unwieldy for most applications except competition and some very specialized law enforcement operations.

What shotguns do you support with your telescoping stock kits?

Our focus is on law enforcement platforms, which means we make stock adapters for the Remington 870 and Mossberg 500/590.

As you read this, we might have some High-tube adapters available for the Winchester 1300, but when we sell the last of those we will no longer be producing any more.

Why don’t you support Benellis, or any other semi-automatic shotgun?

Virtually all semi-automatic shotguns feature a recoil spring tube projecting out the rear of the shotgun receiver and running back through the stock at an angle. This means there is no way to attach one our our stock adapters to a semi-automatic shotgun. It just can’t be done.

We have been working on solid stocks for the Benelli, as well as a variant on the factory collapsing stock for the Benelli M4, but these are very different from our standard AR-15 style telescoping stock kits.

Can you make me a custom stock adapter?

We wish we could, but our stock adapters are investment cast, which means lots of tooling and other up-front expenditures were involved in their development. While the backs of the adapters are common to all AR-15 telescoping stock assemblies, the front of the adapters are very different, even in the raw castings. So we are not in a position where we can simply machine a casting differently to fit a different gun, not for less than a couple thousand dollars apiece anyway.

If, however, we become convinced that there is a large enough market to warrant manufacturing adapters for a different brand or model of shotgun, we will consider a product line expansion.

Keep in mind it will take us about nine months from the beginning of the project before we will see production products.

What kind of sling mounting options are there with your telescoping stock systems?

All our stock adapters include provision for a steel “flush cup” that accepts a push-button sling swivel. With the LEO adapters the cup is installed at the factory; with the High-tube and Low-tube adapters, the cups are optionally installed in the field by the user.

All our stock kits include a push-button sling swivel. If you purchase the stock adapter separately (without the buttstock, grip, etc), the push-button sling swivel is not included, though the adapter will still include the “flush cup.” These push-button slings swivels are on the Uncle Mike’s pattern and can be found at almost any gun store.

Our High-tube and Low-tube stock adapters can accept any of a series of Adapter Mount Sling Loops and Hook Loops. These are basically stamped steel pieces that can be bolted to the mount points on the sides of the stock adapters. Stock adapters for the Remington 870 include a novel sling mounting capability in which a pocket is cast into the adapter that can accept a stamped steel sling loop or hook loop between the adapter and the shotgun receiver. Unfortunately, there is no way to include this feature with our stock adapters for the Mossbergs.

Does Mesa Tactical sell complete shotguns, or any other guns?

We are neither equipped, nor licensed, to sell firearms. Your best bet is to buy your gun from a local dealer, and also have him supply the Mesa Tactical components you want on your shotgun.

Can I buy your stock adapters without the stock and pistol grip?

For those customers who may prefer some other after-market stock, or who already have an existing AR-15 stock and pistol grip, we do sell the adapters separately. However, our complete stock kits offer the easiest way to convert your shotgun.

See our catalog for specific ordering information.

Will your adapters work with all AR-15 compatible after-market stocks?

All of our adapters will accept nearly all AR-15 compatible telescoping stock and AR-15 pistol grip assemblies. The High-tube adapters are designed to look exactly like an AR-15 lower receiver from the back. However, AR-15 pistol grips with an exaggerated front duckbill will fit, but the extended duckbill will hang in space.

The Low-tube and LEO Adapters, on the other hand, accept only AR-15 receiver extension tubes that are essentially identical to the original AR-15 version, and stocks made for those tubes, essentially variants on the CAR stock or M4 SOPMOD stock. The rule of thumb is if the stock requires the indexing dimple found below the receiver extension tube interface on the AR-15 lower receiver, it can’t be installed on the Low-tube or LEO adapters (though it will work on the High-tube, which can accept any AR-15 stock).

Finally, pistol grips with large beavertails will not fit on the Low-tube or LEO adapters.

How do the Low-tube and LEO adapters accept stocks without using that indexing dimple?

We had to design a specialized claw type indexing plate, which we supply with each Low-tube and LEO adapter to use in place of the indexing plate normally supplied with standard AR-15 stocks. The photo shows the claw type indexing plate alongside the back of a Low-tube adapter, and the photo on the right shows the claw type indexing plate installed.

How difficult are your stock kits to install? Will I need a gunsmith?

Our stock kits, and adapters, are pretty easy to install. The hardest part might be removing the factory stock, for which you usually need a long flathead screwdriver and some patience.

To install our stock kits, and adapters, all you need to supply is a Phillips head screwdriver for the grip; we supply the proper keys needed for all Allen or Torx head screws, which we also supply. The telescoping stock’s receiver extension tube simply screws into the back of the adapter, and is locked into place by a locking Castle nut and index plate, which you can either tighten by hand, with a set of channel locks, or by using a special AR-15 Castle nut wrench, available from Brownell’s or at gun shows. You will probably want to use some Loctite® thread locker when everything is buttoned up the way you want it.

There is no fitting, filing, drilling, tapping or other gunsmithing of any kind required for the conversion.

How does your Enidine recoil buffer work?

Our recoil stock kits simply replace the hollow receiver extension tube that holds the buttstock with a hydraulic shock absorber from ITT Enidine. The buffer acts exactly like an automatic shock absorber, letting the shotgun move up to 3/4” back into the stock when fired.

How well does the recoil buffer work?

Extensive testing has assured us that at least 70% of your shotgun’s recoil will be absorbed by the Enidine recoil buffer before it can reach your shoulder.

Does the Enidine recoil buffer require any kind of maintenance?

We would suggest that it be kept clean just like the gun itself. Although, we guarantee it for life, excluding unusual wear or severe damage. The unit does not require any kind of internal maintenance and Enidine has tested the unit through 20 million cycles, and we’re betting that none of our customers will ever shoot 20 million rounds through their shotgun, hence we feel confident about our lifetime guarantee

How accessible is Mossberg’s safety if I decide to use a High-tube telescoping stock kit?

We designed the Mossberg High-tube telescoping stock kits to use either an adapter mounted Picatinny rail, or a receiver mounted Picatinny rail. The receiver mounted rail allows easy access to the Mossberg’s thumb operated safety. Mossbergs manufactured in 1996, and later, have tapped holes on the top of the receiver, and our receiver mounted rails match Mossberg’s hole pattern. However, if your Mossberg was manufactured prior to 1996, you will probably need to have a gunsmith drill and tap holes to match our rail, or use our adapter mounted rail with somewhat restricted access to the Mossberg’s safety. The above photo shows a Mossberg 500 with our High-tube telescoping stock Kit and receiver mounted Picatinny rail. Note the unrestricted access to the Mossberg’s thumb operated safety located on the top of the receiver between the adapter and the rail.

I have a Remington 870 20 gauge shotgun. Will your stock adapters work on my gun?

The Remington 870 20 gauge shotgun has a slightly smaller receiver than the 12 gauge. Our Low-tube and LEO stock adapters will work, but the edges of the adapter extend slightly beyond the edges of the shotgun’s receiver where they join together at the rear of the receiver. The slight difference in size is a minor cosmetic issue, and does not affect performance. On the other hand, our High-tube adapter also works, but has a little more overhang, and raises the Picatinny rail too high to be supported at the front of the receiver, otherwise the High-tube can be made to work, but without the rail.

What about Remington’s 7615 Rifle? Will your adapters also fit on the 7615?

The 7615 receiver is essentially the same as Remington’s 20 gauge model 870 shotgun and the same issues that apply to the 870 also apply to the 7615. See above comments. The photo below shows our Low-tube adapter installed on a Remington 7615. The 870 20 gauge would be the same as the 7615 rifle.