Bedding a scope mount
Mar 22, 2015 11:58:50 GMT -5
Post by Richard on Mar 22, 2015 11:58:50 GMT -5
Bedding a scope mount
I thought I would put this together for those that are unfamiliar with bedding a scope mount and why it is done…………At least this is my take on it. For the purpose of this discussion lets consider the Remington action as the receiver has two different radius on the front portion and rear portion.
In manufacturing there will always be tolerances no matter what the product and actions are not exempt. So consider the forward part of the action as being round and the top of the rear section as elliptical (sort of). Two separate operations to machine them. Also, they are not parallel to one another. Next, lets look at the mounts………….manufacturing tolerances are also present here? So couple the tolerances of both…………..and particularly the mounts……since there are so many different brands…………Leupold, Burris, Millet, Lyman CHINESE, and on and on. Then there are one piece (preferred) and two piece mounts. So you can see where not every combination is going to mate up precisely (receiver to mount). IF, they are not perfectly in line, then your rings will not be parallel. This means that when you tighten the rings around your scope, you could put dents (crush) in it. If you crush it too much in the area of the inner erector tube (which contains your crosshairs) it could impede adjustments……………Hence the reason you really want your mounts bedded.
Bedding two piece mounts can be a real problem unless you have some experience so I will bypass doing this type. Again, I personally prefer a one piece mount. The reason being mainly, that the top mounting surface should, in most probability be FLAT or STRAIGHT. Now the underside, (the part that mates with the receiver) NOT necessarily so………… This is where the bedding comes in.
The first thing I do is install the mount on the receiver (making sure the receiver surface is clean and smooth). I will attach it with one forward and one rear screw. I then mask around the perimeter of the mount. This allows for easy clean up of the epoxy. Then remove the mount. Rough sand the underside (mating surface) for good adhesion. Next, mask (tape) around the base of the mount (again for easy clean up) of the mount. Take your screws and coat them with a “release” agent. Shoe polish or furniture polish works well. Use that same release agent on the surface of the receiver.
Next mix up your epoxy……..I use Marine Tex or Devcon F or you can use J-B Weld and coat the bottom of the mount…….keeping it a little away from the screw holes (it will squeeze in close to them as you tighten the mount but you want to keep it from getting into the holes before you put the screws in). I generally use a thin punch or nail (front and rear) to guide the mount as I place it on the receiver. Now remove the nails and carefully install the screws. Begin to snug them down evenly but not tight. Once you get the epoxy squeezing out the sides and you feel the screws begin to tighten, back off a hair so there is no pressure…………………Let cure. In the picture you can see I removed the tape on the receiver. I did this after I ran a thin screw driver around the base to remove the excess.
Once cured, remove the screws; you can take a piece of wood, screwdriver handle and tap on the mount and it will come off. Remove the tape on the mount and clean up the edges with a fine tooth file or sand paper on a block. Also take a drill bit and clean out the holes in the mount as epoxy will have squeezed up into them.
So now you have a mount that is mated perfectly to the receiver and when you tighten the screws, there will be no torqueing or distorting of the mount.
IF, you want to take this process one step further, you might want to consider lapping the rings. This will insure that the scope is laying parallel to the inner surface of the rings. An alternative is using the Burris Signature rings with the plastic inserts?
Richard
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I thought I would put this together for those that are unfamiliar with bedding a scope mount and why it is done…………At least this is my take on it. For the purpose of this discussion lets consider the Remington action as the receiver has two different radius on the front portion and rear portion.
In manufacturing there will always be tolerances no matter what the product and actions are not exempt. So consider the forward part of the action as being round and the top of the rear section as elliptical (sort of). Two separate operations to machine them. Also, they are not parallel to one another. Next, lets look at the mounts………….manufacturing tolerances are also present here? So couple the tolerances of both…………..and particularly the mounts……since there are so many different brands…………Leupold, Burris, Millet, Lyman CHINESE, and on and on. Then there are one piece (preferred) and two piece mounts. So you can see where not every combination is going to mate up precisely (receiver to mount). IF, they are not perfectly in line, then your rings will not be parallel. This means that when you tighten the rings around your scope, you could put dents (crush) in it. If you crush it too much in the area of the inner erector tube (which contains your crosshairs) it could impede adjustments……………Hence the reason you really want your mounts bedded.
Bedding two piece mounts can be a real problem unless you have some experience so I will bypass doing this type. Again, I personally prefer a one piece mount. The reason being mainly, that the top mounting surface should, in most probability be FLAT or STRAIGHT. Now the underside, (the part that mates with the receiver) NOT necessarily so………… This is where the bedding comes in.
The first thing I do is install the mount on the receiver (making sure the receiver surface is clean and smooth). I will attach it with one forward and one rear screw. I then mask around the perimeter of the mount. This allows for easy clean up of the epoxy. Then remove the mount. Rough sand the underside (mating surface) for good adhesion. Next, mask (tape) around the base of the mount (again for easy clean up) of the mount. Take your screws and coat them with a “release” agent. Shoe polish or furniture polish works well. Use that same release agent on the surface of the receiver.
Next mix up your epoxy……..I use Marine Tex or Devcon F or you can use J-B Weld and coat the bottom of the mount…….keeping it a little away from the screw holes (it will squeeze in close to them as you tighten the mount but you want to keep it from getting into the holes before you put the screws in). I generally use a thin punch or nail (front and rear) to guide the mount as I place it on the receiver. Now remove the nails and carefully install the screws. Begin to snug them down evenly but not tight. Once you get the epoxy squeezing out the sides and you feel the screws begin to tighten, back off a hair so there is no pressure…………………Let cure. In the picture you can see I removed the tape on the receiver. I did this after I ran a thin screw driver around the base to remove the excess.
Once cured, remove the screws; you can take a piece of wood, screwdriver handle and tap on the mount and it will come off. Remove the tape on the mount and clean up the edges with a fine tooth file or sand paper on a block. Also take a drill bit and clean out the holes in the mount as epoxy will have squeezed up into them.
So now you have a mount that is mated perfectly to the receiver and when you tighten the screws, there will be no torqueing or distorting of the mount.
IF, you want to take this process one step further, you might want to consider lapping the rings. This will insure that the scope is laying parallel to the inner surface of the rings. An alternative is using the Burris Signature rings with the plastic inserts?
Richard
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upload photo
. Now maybe I can go back and bed the base on my 6.5x284. Although that gun didn't SEEM to need it I am sure it wouldn't hurt. Talk soon. 
