Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte Adapt and Conquer!


“The Weaver T-22 2-Piece Adapter Scope Base allows you to use Weaver-style rings on a rifle designed for use with 3/8″ dovetail accessories. It provides a sure, tight fit for the ultimate in reliability”. – Source: Weaver Optics


  • Converts 3/8-inch grooved receivers to accept Weaver style rings
  • Lightweight, aircraft-grade aluminum for rugged performance
  • Slotted bases accept Weaver-style scope rings
  • Windage adjustable (Author’s note: I go into this a bit later)


Recently, I had the challenge of affixing a magnified optic to the Henry AR-7 U.S. Survival Rifle.  The receiver consists of a slotted 3/8’ optic mount that is compatible with 3/8” dovetail scope mounts.  I had an inexpensive Leapers scope that I wanted to try out and, fortunately, I found a set of very inexpensive scope rings with QD mounts that would fit the base and also have just enough clearance above the rear sight shroud on the AR-7. I needed something a little more stable that would allow me better scope ring options.  A web-search for dovetail-to-weaver mounts led me to the Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte, which was available at my favorite shopping place – Midway.com.

The Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte is a set of two aluminum adapter pieces that can be attached, via two flat-head screws per section, to any 3/8” dovetail slot. The mounting screws are also knurled to allow for tightening by finger. The question would be well they work. I will answer that question shortly.

Installation is simple. Center the adapter within the grooves and tighten each mounting screw evenly.

The adapters are well-finished and matte black in appearance.  Each adapter has a slot in which the locking blade of a scope ring with a Picatinny or Weaver scope mount can reside. This provides a lot of flexibility in determining the correct mounting position for the optic. The scope rings are simply mounted to the adapters, and the unit is then mounted to the dovetail slot in the rifle’s receiver, positioned for the best mounting position, and then the entire unit is tightened down with the two mounting screws.

The adapters add an appreciable amount of height to the scope setup.

  • Height: 0.527 inches (measure from the highest point of the adapter)
  • Width: 0.835 inches (measured at widest “Weaver” mount point)
  • Length: 0.945 inches
  • Notch width: 0.157 inches
  • Notch Depth: 0.010 inches

There are many such adapters on the market. Due to the nature of the AR-7 – the capability of storing the action in the stock, I wanted an adapter that I could quickly remove or install without the use of a Hex-head wrench. The Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte provided what I needed in that respect. I also wanted an adapter that would allow for a myriad of scope ring styles, QD or otherwise. Would the Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte fit the bill?  Well, yes and no.

I was able to successfully mount the adapters to the Henry AR-7.  I was also able to successfully mount a Leapers (UTG) CQB 30mm Red/Green dot CQB sight to the adapters. For my intent and purpose; however, the Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte was not going to work for me on the Henry AR-7. Allow me to explain the reason why.

The Weaver T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base Matte is actually intended to remain on a firearm as a semi-permanent mount and is not useful as a QD mount. There is a screw on each side of each adapter to position it in the dovetail groove.  Being that there are two screws, there is no guarantee that each adapter will be centered in the groove. This is where the “Windage adjustable” comes in as claimed in the specifications. The adapters could actually be shifted from side-to-side by simply loosening one mounting screw while tightening the other, essentially changing windage point. Now, this could be an advantage, and some scope rings come with “shims” that can be used for adjusting for windage should a scope run out of windage adjustment or have alignment issues.  The disadvantage, as I see it, is that it adds a level of complexity that I don’t want; I like neat and simple. There are also firearms that use this technique to adjust windage on certain adjustable rear sights, and many reflex sights, as a cost saving effort.

The adapter works well with rounded receivers, and they work well with the Henry AR-7 receiver, but they don’t fit the intent and purpose that I was looking for with the Henry AR-7. With that said, they do work well on other dove-tail mount firearm receivers. And, with that said there is something that you need to consider – locking down the mounting screws.  With other adapters on the market, there may be multiple locking screws that tighten the adapter from one side only and these make for very stable mounts. As the Weaver T-22 mounts come with two screws per section, a mounting screw on one section that comes loose could cause a shift in POI, which is not desirable.   Regardless of caliber, optic base mounting screws can loosen.  The usual procedure to prevent that from happening is to apply the proper torque to the screws and the use of a thread-locking compound and which is something that I absolutely recommend with the Weaver T-22 adapter.

In closing, there are many 3/8-inch Dove-tail groove to Weaver (and Picatinny) adapters on the market and you will need to do some research to determine what is best for your particular application. Most adapters will suit the purpose of providing a means to mount a Weaver or Picatinny scope ring on a rifle or shotgun. There are also several scope rings that allow you to mount a 30mm or 1” tube diameter scopes to a dove-tailed receiver. In fact, one consideration of mine was to purchase a set of 30mm rings that would mount a 30mm tube red dot to the AR-7, but research turned up a red dot sight that was intended to mount on a dove-tail receiver, which to me was the better option.

The T-22 2-Piece Adapter Scope Base 3/8″ Grooves to Weaver-Style Base does work for its intended purpose.  My only purpose with this article is to point out some things that the manufacturer doesn’t tell you.  I hope that you found the article informative.


T-22 Base Pair Converter: http://www.weaveroptics.com/rings_bases/mounting_systems/t22_base_pair_converter/


About Taurian

Taurian is a U.S. Army veteran and former LEO and Defensive Tactics Instructor. Taurian also has over fifty years of experience as a Technical Writer and Training Program Developer. After leaving home at the age of ten without any shoes, Taurian continues on with many years devoted to the keeping and bearing of arms.

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