The information below is from the Barrett web site.
Barrett ExRings™ provide an easy, adaptable solution to a common
challenge for long range shooters. With some scope/rifle combinations,
a shooter may find they do not have enough “up” elevation adjustment in
their scope to hit targets at the maximum range of their rifle system.
When this condition exists there is usually plenty of “down” elevation
adjustment that is not being used. By elevating the rear of the scope
the correct amount, a shooter can maximize the internal elevation
adjustment range of the scope for the practical range limits of the
In the past, this problem
has been addressed with a scope rail that is machined or installed on
the rifle with a built in taper to provide the needed elevation.
Depending on the available internal elevation adjustment of the scope
and the trajectory of the cartridge being used, one particular
elevation taper may not be perfect for every configuration. If you are
using a rifle that has an integrated rail that is parallel to the bore,
or desire the adaptability of selecting variable elevation settings,
Barrett ExRings are the solution.
Barrett ExRings with Pin-Lock™ technology has a dual setting MOA taper
at 20 MOA or 30 MOA, utilizing the riflescope’s precise internal
elevation adjustment by aligning the scope for long range shooting. The
front ring assembly is designed with a precision fit pivot that allows
the scope to elevate in the rear, but tolerances insure no unwanted
movement. The rear ring assembly houses the Barrett Pin-Lock technology
that allows the user to select from two MOA settings. Once a MOA
setting is selected and the ring’s four cross bolts are torqued to
specification, Barrett ExRings become a rock solid mount with the
correct taper to maximize the potential of your rifle system.
The unique scope clamping design of the ZERO-GAP™ feature takes care of some
old optics mounting challenges. In the past, great attention was required when
securing scope ring caps to maintain an equal gap between the lower ring and top
cap on each side. There was also the possibility of rotating the scope out of
perfect vertical reticle alignment while torquing the cap screws in a side to
side pattern. These problems are eliminated with the ZERO-GAP design. Simply
secure the cap on the indicated side until there is no gap between lower ring
and cap, check for perfect reticle alignment, and then torque the remaining side
to the required specification.
- ZERO-GAP™ offers wider clamping area and maximizes “scope grip”
- Fits MIL STD 1913 rails
- Maximizes the riflescope’s internal elevation adjustment for long range
- Zero backlash tongue and groove interface for precision fit
- High Strength Aircraft grade 7075 T6 aluminum construction
- 2.5x lighter than steel
- Heat treated steel cross bolt and captured nut for increased strength
- Hard Anodized with a 60HRC (Rockwell C scale)
- BORS compatible
The rail clamping cross bolt and nut are precision machined from hardened
steel alloys. The cross bolt is securely pressed into the scope ring base, and
the end of the bolt is staked to retain the nut. The cross bolt is designed with
a broad shoulder to perfectly interface with cross slots of mil spec 1913 rail
to resist even the harshest recoil. The top cap of each ring is retained by four
robust Torx screws placed with broad spacing to provide consistent and evenly
distributed clamping force.
Barrett ExRings are wider than typical rings at 1.2 inches. This creates a
greater surface area of contact between the ring and scope maintube. The benefit
is a secure grip on the optic that will hold up under heavy recoil. Along with
this solid connection comes protection for your expensive scope. The broad
clamping area spreads out the forces and reduces the likelihood of denting or
distorting the scope tube. The same benefits in scope holding translate
directly to the mounts ability to hold on the rail. More width in rail clamping
area is better.
All critical features on Barrett ExRings are machined with great care. The
30mm bore will be exactly that with a diameter tolerance of plus or minus .001”,
perfect roundness and position in relation to the mounting rail. Angles and
surfaces in the rail clamping feature of the lower ring are held to great
positional tolerances to insure the scope is held centered when bolted up to the
Every component of Barrett ExRings is carefully handled all the way to
packaging. All edges are beautifully rounded to prevent snags and resist corner
wear. The 7075 T6 components are hard anodize coated in black to mil spec
MIL-A-8625 Type III Class 2 specification for superior surface hardness (60
Rockwell) and resistance to wear. Steel components are manganese phosphate
coated to mil spec DOD-P-16232 Type M Class 2 specification.
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Note: Barrett recommends 35 inch pounds of torque on the top screws. We have found that this can and usually does cause damage to the scope tube and highly recommend that you start with 15 inch pounds and do not exceed 20 inch pounds of torque for the top screws unless absolutely necessary to prevent scope movment in the rings. If you still have movement of the scope at 20 inch pounds, then lightly dust the inside of the ring with powdered rosin. It is a good practice to use rosin in all hard recoiling applications. It can be found at most sporting goods stores and is a very fine flour like powder that gives exceptional gripping power to the rings without the chance of denting the scope tube by over torquing the ring top screws.