Rifle Scopes Is it necessary/beneficial to bed scope bases?

xj92

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<span style="color: #FF0000">Is it necessary or beneficial to bed scope bases, and if so, what is the best method? </span> I've read some threads already on this a little, and there are people on both sides of the fence. I would like to<span style="color: #FF0000"> know why it is or is not necessary, and what the best way to do it is </span> . Has anybody had a base loosen up after simply cleaning the threads and using blue loctite? I read an article here about it. Comments?
 

ToddM

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Re: Is it necessary/beneficial to bed scope bases?

I've never had a base loosen up that was properly torqued. The big reason to bed the base is to try and eliminate any torque/twist on the base from the action/base interface not being perfect.

I've done them two ways. The first being trying differnt single screw combination to try and find one that leaves the other end of the base off the receiver, then bed using that screw only (the others are loosely installed to keep epoxy out and align base). The second is to bed the base using the two inside screws. I haven't had a problem with either. In theory I like the single screw method better, as to me in putting in two screws on either side even the inside ones, you can be potentially twisting the base. The upside is you get good metal to metal contact on both sides of the base.

The best way is to bed the base, mount it and your rings, and then use a set of scope ring alignment tools to verify that the rings are aligned. Usually after bedding the base either of the above ways it's significantly closer than before bedding it. At that point depending on how close it is to perfect I'll lap the rings or mount the scope and go.

people have not bedded bases way more than those that have, and their systems work fine, don't fall off, still shoot true, so certainly it's not a requirement, and with a custom receiver I wouldn't bother with it (though I do still check my rings with the alignment tools).

I guess the bottom line is if you mount everything up, and use alignment tools and it says it's aligned it's all good, I wouldn't bother bedding, this has rarely been the case in my experience with factory guns. If not I'd try bedding the base, and check it again, if it's still only a tiny bit off, I'd lap the rings to get it perfect. If it's quite a bit off I'd try different rings etc.

The argument that the rings or base are machined to perfect tolerances is fine, and I don't doubt it in many cases. The issue becomes once you mount everything up tiny differences show up and things get slightly out of alignment. That to me is why you lap, I'll bed my bases just because in my experience it has reduced the amount of alignment issue, but with factory rifles I've yet to see a base/ring setup from any maker end up being absolutely perfectly aligned using a gauge. Is it necessary....nah you can mount a scope up on a set of rings that's not quite perfectly aligned and be fine, I see it every other day. I'd just prefer it to be as close as possible out of the gate.

Usually with anything so controversial as lapping rings, the fact that there is no clear cut winner and people do it both ways very successfully means either way can work just fine.



 

MAX100

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Re: Is it necessary/beneficial to bed scope bases?

I believe it is a waste of time unless you have a really poorly machined base. In that case I would send it back and buy a higher quality base.

It is beneficial to bed the back of a base if you are wanting to add height for more top end adjustment to your scope.


GC
 

BOLTRIPPER

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Re: Is it necessary/beneficial to bed scope bases?

savvy the potential of corrosion setting in...i believe the m40A1's were bedded ....mostly to make them gorilla proof
 

MAX100

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Re: Is it necessary/beneficial to bed scope bases?

You you want to go go-rilla proof have the receiver drilled & tapped for 8-40 screws. That would be more beneficial than bedding.


GC
 

Aqua Mark

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Re: Is it necessary/beneficial to bed scope bases?

If the receiver isn't true, then yes. REM 700 receivers are infamous for this. To check yours:

Torque just the front 2 base screws. Check with feeler gauges the rear area of the base to see if there is a gap. I have seen gaps up to 0.015" in the rear base area.

Here is a shim I cut to fit the 'low spot' in my last 700P, 0.0015" thick shimstock was needed for this particular rifle:
SHIM PIC

You could also bed the base, it will fill in the low spots. Clean it up, and when it cures, torque all the base screws with loctite.

Either way the base now sits neutral, w/out stress.
 

MAX100

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Re: Is it necessary/beneficial to bed scope bases?

I would think if a receiver is not true it would put more stress on the base screws than the base itself. Epically a steel base. I have never bedded a base and never had any problems. I would say the very large majority have never bedded thiers either and never had problems.

I say do what will give you peace of mind.

GC
 

craigp40

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Re: Is it necessary/beneficial to bed scope bases?

I've never bedded a base until this past week. I had a 20 MOA base that was essentially negated by the tolerances on the action.

Does my rifle shoot any better now that the base is bedded? No.
However, I got back 15 MOA of elevation out of my base that wasn't there before due to the base being torqued down when all screws were tightened. I don't plan to do this to all my bases, but I will do it to the ones that show this issue.
 

HuDisCo

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Re: Is it necessary/beneficial to bed scope bases?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">savvy the potential of corrosion setting in...</div></div>

This is the best reason. At the minimum I put a big drop of locktite under the base(s) and make sure it comes out all sides. If you ever subect your rifle to moisture I would recommend it.
 

ArcticLight

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Re: Is it necessary/beneficial to bed scope bases?

I just took my base off my rifle day before yesterday.

Back in 2001 my smith put it on, there was a gap in it, you could see daylight and we talked about the bed ding and he said...

"That's why I put 8x40 screws in and loctited them down".

As for corrosion, I believe that is why he said he also did not bed the base.

My rifle shot under .5 MOA when I was having a good day...

PS there was no corrosion underneath, have not seen that part of my action in 9 years
smile.gif
 

craigp40

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Re: Is it necessary/beneficial to bed scope bases?

Ok, I need some edumacation on a point above. Why does switching to 8x40 screws solve the issue? If the base and top of the action are not flat to one another, the base will still flex under torquing of the screws regardless what size they are. Please explain.
 

Nocalphoenix

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Re: Is it necessary/beneficial to bed scope bases?

Exactly Craig. If a receiver was not properly fitting your stock the answer would not be a bigger action screw or even more torque.

I bed all of the bases on my factory actions for the same reasons I bed the stock. They may perform just fine without it but Im now assured of a perfect fit with no doubts of anything mechanical taking away from my sorry ass ability to hit the target. You only need to do it once and it is not a very involved process.