Will bedding a scope base and lapping the rings have the same effect?

84wh1

84wh1

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As the title says, will lapping my scope rings produce the same affect as bedding my scope base? If not, would you precision guys recommend both, or one or the other. I usually lapp my rings, but ive never bedded a base.

Cheers

BTW, its for a rem 700 sps 308 HB with an EGW base.
 
For the base - lay the rail on the action now press on the back of the rail. Does the front of the rail lift up? Now do the same pressing on the front of the rail. If the rail does not lift up on either end there is no advantage to bedding it.

Lapping rings increases the surface contact between the scope and rings and helps alignment between the rings.
 
84wh1 said:
As the title says, will lapping my scope rings produce the same affect as bedding my scope base? If not, would you precision guys recommend both, or one or the other. I usually lapp my rings, but ive never bedded a base.

Cheers

BTW, its for a rem 700 sps 308 HB with an EGW base.
Click to expand...


That is 2 entirely different procedures. Both of which can be negated by purchasing high quality parts.
Bedding a rail is typically done to correct the fitment between the action and the rail. Some "bond" the rail to the action as they do not believe a series of screws is sufficient to keep the rail attached to the action.
Lapping rings is done to create perfect alignment and concentricity of the rings so as to not put a pressure point on the scope tube.
 
jonh172 said:
Bedding the rail relieves stress on the action, lapping your rings relieves stress on your scope.
Click to expand...

Does anyone really believe that a rail will stress an action to the point of measureable difference? I'm not saying that it's impossible but I really doubt it, unless you had a monster of a rail and some wild torque on the screws. Just my opinion.

Rooster
 
358Rooster said:
Does anyone really believe that a rail will stress an action to the point of measureable difference? I'm not saying that it's impossible but I really doubt it, unless you had a monster of a rail and some wild torque on the screws. Just my opinion.

Rooster
Click to expand...

I would think that even with 8x40 screws, the screws would break before the action started to deflect any measurable amount.
As you state, 1 would need a VERY strong rail and larger than normal fasteners to start bending any decent action in any measurable amount.
Rings however, that are mismatched or out of alignment will bend a scope tube easily just with fastener torque.
 
Lots of good comments already. My 2 cents would be that in my experience most mass fabricated rifles such as the Rem 700 tend to be somewhat out of spec both in terms of misaligned holes and most commonly a height difference between the front and rear base mounting points. Usually when mounting a quality one piece rail it can be assumed that the rail has been machined precisely and accurately. When you mount the rail using only the front 2 screws there is often a gap under the rear end of the rail (I have seen up to 1mm). This is the gap that needs to be bedded. If it is not bedded but tightened down it will pull down the rear of the rail and deform it. If this stresses the action or not is debatable. What it for sure does it put a slight curve in the rail, which means your rings will not be perfectly parallel to each other and will apply uneven stress on your scope tube. In this case it doesn't matter how high quality your rings are or if they are perfectly machined; they are not mounted on a perfectly straight surface (rail).

Once you bed the rail (if needed) and use high quality rings there can still be some factors slightly affecting how parallel and in line with each other the rings are.

I always bed my rails if required, and then always lap the rings. If you are using two piece picatinny rails it is a bit tricky to determine if one of them needs to be bedded; using a ring alignment tool will show you if there is a height difference.

In my opinion the only time you don't need to lap rings is when using a quality once piece scope mount (like a nightforce etc) where the rail and rings are machined out of the same piece of material. It might still need to be bedded though.
 
I have two sets of scope bases for my 700 from EGW. The 0MOA one needed the back end to be bedded. If I snugged down the front screws, there would be a 1/1000 gap between the rail and receiver at the rear end. The 20MOA rail fit perfectly and did not need bedding.

I could have screwed down the 0MOA without bedding it but that would have resulted in a possibly bowed rail and that in turn would put uneven stress on the scope tube when I tighten down the scope rings.
 
358Rooster said:
Does anyone really believe that a rail will stress an action to the point of measureable difference? I'm not saying that it's impossible but I really doubt it, unless you had a monster of a rail and some wild torque on the screws. Just my opinion.

Rooster
Click to expand...

In the search for the best accuracy it is good to not induce any stress to the action when bedding it or adding bases to it... you may not be able to measure this stress but you would always wonder when that one shot opens up a group...
 
Today, I was shooting a new-to-me gun and noticed that loosening the rings made it shoot to a very different point of impact and a smaller group - to I decided that rather than lap the 30mm rings ( I don't have a 30mm bar handy), I would lap the bases to line up better with each other. It is a two piece base. It seemed like the rings were trying to bend the scope, and rather than try to lap it all out of the inside of the rings, I could lap the top angle of the bases to line up better - then I lapped the inside of the rings - it only required a little. The top angle of the bases are what the rings seat to.

Lately, I have been using lock-tite to bed the scope. I put a thin coat of it on the bottom half of the ring - I don't worry about the top half. After the scope has been in it with the screws half-tightened for a few hours, I finish tightening it down. It will keep the scope from sliding under recoil, and is really easy to take it off when I pull the scope off. I notice that the release agent for action-bedding compound is an easy-to-remove coating, so it might even work as a scope bedding compound. Likely anything would work - Elmers wood glue might work - I'll try it next time.
 
Thanks guys. The base is an EGW 20MOA, the rings are Burris Extreme Tactical and the scope is a bushnell Elite tactical ERS 6-24 FFP. I put the base on last week but didn't do anything more than toss a little loctite on the screws and screwed them down to torque spec. I will remove the base later on and check if it needs bedding.

Thanks
 
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