Gunsmithing bedding a scope base

[Witch_Doctor]

Ok I have read the how to's, searched the internet, searched the Hide, and now my question: when you apply the devcon to the base, do you apply release agent to the bottom of the base and the top of the action? I know I need to add a liberal amount to the base screws, but I am a bit hazy on the other.

It would seem that if I applied release agent to both I would end up with a piece of devcon like a gasket. I can't seem to wrap my head around it. As a side note my action is pretty straight, and the BO base sits without gaps. Which why does BO say to apply loctite to the bottom.

 

[doc76251]

Re: bedding a scope base

I would apply the devcon to the base and put release on the rifle. Much easier on your conscious to grind on the cheap part.

Cheers,

Doc

 

[sobrbiker883]

Re: bedding a scope base

^
what he said.
The only release you may want on the base is on the sides to trim up easier. Don't forget the release agent in the holes on the base and receiver and on the screws themselves. Hell even put some on the top of the base around the holes.
I'd spray some in the action too, just in case you get a teeny drop that squeezes through........

 

[Witch_Doctor]

Re: bedding a scope base

Yea thats what I thought too, quite logical also, but I have never bedded a base before.

 

[Lindy]

Re: bedding a scope base

Badger's instruction on mounting bases and rings says: <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Apply a light coat of loctite to the bottom of the base, this will stop water from wicking between the base and the mount and potentially cause rust over time.</div></div>

It doesn't say anything about bedding the base, and I've never done so. Why are you?

 

[Witch_Doctor]

Re: bedding a scope base

tinkering

 

[Lindy]

Re: bedding a scope base

Daniel Webster, a wise man, said,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A strong conviction that something must be done is the parent of many bad measures.</div></div>

 

[Witch_Doctor]

Re: bedding a scope base

Oh you are right, I haven't done it yet, and I am remember JRose's foray into it. I still don't get the loctite thing though. I realize its to stop the moisture wicking, but why red or green loctite? Couldn't you just use blue.

 

[Lindy]

Re: bedding a scope base

My experience has been the Marty Bordson, who owns Badger, usually has pretty good reasons for what he recommends.

In the absence of really good reasons not to, I usually do what he says. I've been doing that for several years without regretting it.

 

[Witch_Doctor]

Re: bedding a scope base

Thanks

 

[Greg Langelius *]

Re: bedding a scope base

Two benefits.

First, it customizes the fit between base and receiver, allowing torque to be applied to the mounting screws without introducing any stresses into the parts.

Second, it can also be used to add a shim/slope value to the base/receiver relationship, maximizing the amount of usable scope elevation adjustment.

This value is established by testing with various shim thicknesses between the receiver and extreme rear end of the base, until the nearest practical zero distance can be adjusted to with the scope's elevation setting at roughly 3-5MOA from the bottom extreme adjustment. Once this value is known, it is established permanently by expoxy bedding the base and receiver with the shims in place.

Greg

 

[sobrbiker883]

Re: bedding a scope base

Only time I'd worry about it is if:
a) one end of the base "floats" when it has no screws installed and the other side is torqued down
b) I needed to adjust the POI for a particular scope like Greg mentioned.

 

[Clark]

Re: bedding a scope base

I either put release agent on the receiver or no release agent.
I either rough up the scope mount underside for glass traction, or not.

Glassing a one piece parallel with the bore or lowered 20 moa in front is easy.

Glassing a two piece parallel with the bore or lowered 20 moa in front takes some real skill.

 

[Bioregulator]

Farrell's Instructions

Things needed:
2 part epoxy (JB Weld is only one of many on the market)
Release agent: 3 in 1 or a good silicone release agent to prevent mount and screws from sticking to receiver.(3 in 1 sells a silicone lube at about $3.00 that works well.)
Q-tips to apply release agent and clean excess epoxy.

• Put release agent on screws and receiver.
• Apply epoxy to bottom of mount between screws and on each side of screws.
• Put all 4 screws in mount holes.
• Set mount carefully over mounting holes in receiver.
• Thread down into the receiver.
• Do not tighten the 2 outer screws. Tighten only the 2 screws next to the ejection port. The outside 2 screws at this time is to prevent epoxy from entering receiver holes.
• Clean excess epoxy from sides of mount using a thinner of some sort (paint thinner, alcohol, or whatever will clean the excess epoxy). Q-tip’s work well..
• After epoxy has set up according to its instructions, you can now loosen and then retighten all screws according to torque specs shown below.
• You now have a very flat mount with little or no distortion in receiver or your mount.

<span style="font-weight: bold">I followed this procedure & was very happy with the results ~ JM </span>

 

[Greg Langelius *]

Re: Farrell's Instructions

I would only add that the quick epoxies don't permit enough working time to allow the user perform the necessary operations without undue haste. After some minor nightmares, I no longer use anything with less than 1hr's worth of working time. This is one of those applications where excessive haste truly makes waste. While epoxy is strong, and curing time is a factor in that strength; I don't think that strength is an issue in this kind of application. The ability to work in a relaxed and deliberate manner is.

Greg

 

[monteboy84]

Re: bedding a scope base

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">Badger's instruction on mounting bases and rings says: <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Apply a light coat of loctite to the bottom of the base, this will stop water from wicking between the base and the mount and potentially cause rust over time.</div></div>

It doesn't say anything about bedding the base, and I've never done so. Why are you?
</div></div>

Why aren't you? Any smith, machinist, engineer or draftsman worth their salt understands that no two machined parts will fit perfectly, even when they're made in the same plant. Here we've got a receiver made at some point over a span of about 50 years or more in a firearm factory, and a scope rail made in the last couple years at a different factory.

While per the prints for both parts they should fit perfectly together, that's simply never the case. While they may fit so properly that the flex of the base is negligible or just immeasurable, it's still there. What happens when you snugly bolt two parts together that don't fit together perfectly? You induce stress, which is detrimental to consistency, and also to accuracy. For about $3 worth of materials and maybe a couple hours of your time, you can perfect the fit and eliminate the stress.

So then I ask, why not do it?

-matt

ETA: Greg Langelius said the exact same thing as me a few posts up, but he did a much better job of summarizing

 

[Lindy]

Re: bedding a scope base

Actually, I am a happily retired engineer.

The art of the precision rifle is based upon making distinctions between what does and what does not matter to the objective of hitting targets at long distance.

My rifles do that. Perhaps I've just been lucky, although the fact that my primary rifle is an Accuracy International may have something more to do with it.

If you have a factory Remington action, which are notorious for sloppiness, then perhaps bedding a base is a good idea. I've never owned such, and have no intention of starting.

 

[monteboy84]

Re: bedding a scope base

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">If you have a factory Remington action, which are notorious for sloppiness, then perhaps bedding a base is a good idea. I've never owned such, and have no intention of starting.
</div></div>

I'd say it has more to do with the fact that the top of the action has two different radii machined on two different height bridges. Perhaps they're sloppy, but it's the nature of the beast, and it's not going to alter its status as the most commonly used tactical rifle in America.

An Accuracy International is a different animal entirely, seeing as how it's a heck of a lot easier to hold .001" straightness and flatness oh the flat top of an AI,than it is to hold dimensional and geometrical tolerances of similar precision on the top of a Remmy action. An AI is a fine weapon, but that's really not pertinent in a discussion of mounting a base on anything with an action lacking a flat-top.

If the top of the action isn't a flat surface, bed it...

-matt

 

[locked&loaded]

Re: bedding a scope base

O.K. You guys have talked me into it....
I'm pulling my base off and bedding it.

 

[x ring accuracy]

Re: bedding a scope base

What was the question? LOL, Happy Bedding, you won't be sorry.

 

[Witch_Doctor]

Re: bedding a scope base

I'm confused, I am going back to iron sights

 

[AKAce]

Re: bedding a scope base

I have never seen bedding a base hurt.... I have seen it help, and I'm sure many more times it has helped that I never knew.

Release agent (I use Pam) on the Action and any place you don't want the Squeeze to stick. IF you are experimenting and will likely make changes.... if not, I use no release on the action or base (Except to handle Squeeze)and let the JB Weld glue the bastard in place. Once it's set up I remove the screws one at a time and add Loctite.... Solid as a Rock