The Picatinny Mounting Rail
that we manufacture, has (14) Cross Slots symetrically spaced
to facilitate any scope tube length. When mounting your favorite
ring style, slots are spaced to give the user optimum adjustment
for eye relief and shooting comfort. Height of the base is approximately
.610 inches tall. Paralellism is held less than .002 inch between
the dovetail clamping area and top of the receiver after mounting.
The screws used are #6-48 x 3/8" long and holes are drilled & counterbored
to the correct depths from the muzzle end to the breach end. This ensures that the
user will not damage their barrel threads or have interference problems over the top of their locking lugs during/after closing the bolt. Most often, manufacturers of scope bases use a very
shallow thread engagement using short screws to minimize these problems while relieving the customer of having to use different
length screws. It is very important that whoever installs the BENCH-SOURCE bases,
uses the screws supplied to maximize thread engagement while minimizing the chance for problems.
The Davidson 1/2" x 60º Mounting Rail dovetail is paralell over its entire
length to optimize mounting your Davidson style scope rings. Accuracy from the dovetail to the action top is also
less than .002 inch to minimize windage correction right out of the box. The screw type and lengths are identical to the Picatinny
and also self centers the mount onto your action when installed per the included mounting instructions. Both ends
of the mount are chamfered slightly on a 30° angle to let the sharp corners of the mating rings align themselves without
binding. The 60º dovetails are machined +/- .001 and measured over (2) optimum diameter pins to minimize over
clamping of your rings. When this happens on other mounts and the rings are removed, they often bind when re-installed
onto a different base that is slightly larger or the same size.
This is one
reason we selected #7075-T6 Aluminum to manufacture our bases from. Aluminum is very prone to galling even with lubrication, and
especially when two mating parts are made from the same alloy. #6061-T6 aluminum is a general grade and is the most often
used aluminum because it is easy to machine and one of the least expensive types. It also scratches and 'dings'
up very easily from normal use.
Both style mounts are available in 0 degree taper
(paralell) and 20 minutes of angle taper. If your shooting is mainly from 50 to 300 yards, stick with 0 degree mount.
If you normally shoot beyond 400 yards, the 20 MOA base will help keep your elevation adjustments to a minimum. Some
of the popular 1" diameter tube scopes used today only have +/- 20 minutes of vertical adjustment from center. This
can be a problem when you want to adjust your windage on a mis-aligned base. If you are near the top limit of vertical
adjustment, you may find that your scope does not respond well or track like it should when making windage adjustments.
If you always shoot 1000 yards or more, you may be interested in puchasing a 30-35 minute
of angle base. If so, give us a call. We are contemplating building bases with 35 MOA of taper for some of the more popular
actions that are chambered in calibers that are less than flat shooting.