Your new JDK BaseAlign tool greatly simplifies precision bedding of two-piece dovetail mount bases on a rifle receiver. It does this by rigidly holding the two bases in virtually perfect alignment. You can then use the same simple bedding technique you would employ with a one-piece base.

We have found the following method to be effective with Remington 700 and 40X rifles::

1. Loosely attach the two mount bases to your rifle’s receiver using the screws supplied with them. Do not tighten the screws; the bases should be free to move slightly when the BaseAlign jig is installed.
2. Make sure the nylon-tipped 10-32 set screws in the BaseAlign do not protrude into the dovetail channel in the bottom of the tool, then slide the BaseAlign onto the base dovetails so both are within the channel. The end of the BaseAlign with two holes and one set screw should be pointed toward the muzzle of the rifle.
3. Position the BaseAlign so the heads of all four mount screws are clearly visible through the holes in the BaseAlign. Using the (supplied) 3/32" hex key, tighten the BaseAlign set screw between each pair of mount screws until the sides of the mount dovetails are held in firm contact with the sides of the BaseAlign’s bottom channel. Unscrew all four mount screws, leaving the bases and BaseAlign as one assembly, separate from the rifle. (If you now hold the assembly on the receiver so the front base is in firm contact with its mating surface, you will probably see a gap between the rear base and receiver. Filling this gap is a primary goal of the bedding process.)
4. Liberally apply a suitable release agent to all surfaces of the four mount screws, particularly the threads. Thoroughly clean and degrease the bottoms of the mount bases and the top of the receiver with an evaporating non-petroleum solvent. If you plan on removing the bases from the rifle after bedding, apply release agent to the top of the receiver. For semi-permanent attachment of the bases (which we recommend), simply leave the receiver clean and dry, so the bases will be glued on, as well as bedded, effectively preventing shifting of the bases when the rifle recoils.

1. Mix a small amount of epoxy bedding compound. Apply a thin layer to the bearing surface of the front base and a slightly thicker layer on the rear base. (Avoid getting any in the screw holes.) Remember, the gaps you are filling are only a few thousandths of an inch in height, so you do not need large gobs of epoxy.
2. Drop the mount screws through the BaseAlign into their holes in the mount bases, so they protrude from the bottoms of the bases. Carefully hold the jig and bases so you can use a hex key to start each of the screws into the threaded holes in the rifle. If possible do not allow the epoxy-covered bases to touch the receiver until all four screws engage the receiver holes by one or two threads.
3. Gently turn in the front-base mount screws until they are just snug, holding the front base in contact with the receiver, but without applying full pressure. At this point you should see epoxy oozing out from under all sides of both bases. Run the rear-base mount screws in another turn or two to make sure they have engaged the receiver threads, but do not tighten them—if you feel a screw head make contact with the base, back it off half a turn.
4. Using a Q-Tip or other suitable implement, wipe excess epoxy from the receiver and mount bases. Put the rifle in a safe place until the bedding is cured (at least 24 hours with most bedding compounds).
5. Starting with the front base, use a hex key to fully tighten all four mount screws. Loosen both BaseAlign set screws, and slide the unit off the rifle. The bedding process is now complete, and the bases should be aligned with each other.

No doubt professional and experienced amateur gunsmiths will be able to think of many variations on the above procedure, and the BaseAlign is designed to permit such creative use. Nonetheless, the technique outlined here works well, and should prove effective for most users.

The types of riflescope mount for which the BaseAlign is made do not normally incorporate horizontal or windage adjustment to correct out-of-line parts or holes in the rifle itself. For this reason you may not be able to obtain perfect alignment of scope and bore centerline, even using the BaseAlign. Usually, however, the lack of stress on scope and rifle that results from enhanced mount alignment will permit both to function with superb accuracy and reliability.

We have seen receivers with scope-mounting holes so far out of line that mount bases could not be aligned while the screws were in place. Should you encounter this situation, you may be able to correct it by enlarging or slotting one or more of the mount-base holes. Alternatively, a competent gunsmith can redrill your receiver so the holes are properly aligned.