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1-piece and 2-piece scope bases have always been a matter of debate. Quality scope bases and rings are almost always made to better tolerances than the tops of our rifle receivers (Remington 700's in particular for some reason). Mike Rescigno (Black Ops of Tactical Operations) and I have discussed this, and in nearly all circumstances we are better off installing 2-piece bases on our 700's to soak up the misalignment between front and rear mounting points on the receivers.

A solid 1-piece base installed on a crooked receiver will surely cause vertical stringing in groups, it's been proven many times. So a 2-piece base is a good solution, but what about those of us who want to run a 1-piece base and avoid the associated vertical stringing?

Bedding of the scope base has been mentioned many times before, and it is the best way to go, but you don't need to bed the whole base, just the end that needs it. So how do we know which end needs it? Try this, find yourself a feeler gauge. Place the scope base on the receiver, but only tighten the screws on one end of the base. With that end tight, attempt to insert the feeler gauge between the receiver and the base on the opposing end (.001" or less should be used because a gap of any dimension requires bedding). If the feeler gauge will fit between, this is the end requiring bedding.

If it will not fit, loosen the base, and tighten both screws on the opposite end from where you tightened the first time. Use the feeler gauge again to check for clearance between the scope base and the receiver on the end of the base that you did not tighten. If you did not find clearance the first time, there should be clearance this time around. Bed the end of the base where you find clearance by coating the top of the receiver with release agent and tightening the opposing end only. Be sure to plug the mount holes in the receiver with modeling clay or wax, you will need to drill the bedding compound in the base holes after it has cured completely.

This procedure will leave your scope base stress free, and it will keep from placing bending forces on your receiver. There should be no vertical stringing on firing, and your scope rings should be perfectly in-line.

This is probably common knowledge to some folks, but it seemed logical to post for those who haven't thought about it. I prefer a 1-piece picatinny base because it allows me to swap optics between firearms without removal of the rings from the optics since the spacing on 1-piece bases is consistent.

Thanks for reading.

-matt

EDITED: Broken into paragraphs for readability. s1's post following this one presents a very good alternative method of 1-piece base installation on a factory receiver. Between these two methods, one should choose a method to fit their preferences, a combination of the two methods is even a possibility.
 

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Discussion Starter #2
Thanks for that input s1, your method makes a lot of sense. What have you found the best way to measure the height difference between the front and rear of the base to be? I would imagine there is a point of reference to measure from that would be consistent from front to rear where you could measure height from.

-matt
 

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!!!

Great infro monteboy84 and S1. I think this is scope related so it's better if it stays here. My opinion.

Slip
 

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Well, I have a new stock and decided to tear everything apart on my rifle. When doing so, I decided to test my 1 piece scope base to see if it had any tension on it. I put the back two screws in and checked the front ... everything seemed ok. I then put the front two screws in, took the back out, and there was a slight gap in the back. So just to double check, I took out all screws and put just the single back-most screw in and torqued it down to 15 inch/pounds. Huge gap! It was about 0.050". This gap existed because the base was not properly seating on the back, causing it to slant upwards (proven by the test where I put two screws in the front and checked the back.)

So I searched around, found this thread, talked to Rob and got an interesting article from him, and decided that I'd bed my scope base. An article that Rob scanned for me showed how to use Loctite 609 to do the job, but I couldn't find any around me and I didnt want to pay shipping for any as I had some Devcon HVAC sitting around for my action bedding job I'm getting ready to do.

So first thing's first, the tools! I gathered everything I'd need and put it on my portable poor-man's workbench:

-Rifle action
-Scope base and screws
-Sand paper (180 grit was all I had)
-Acetone
-Neutral shoe polish
-Devcon HVAC
-15 inch/pound torque wrench
-A few rags
-Vice
-Glass or plastic to mix Devcon on




The first thing I did was use the acetone to degrease and clean off my action, base, and base screws. Since the front of my base sat correctly on the action, all I need to do is bed the rear of the base. I grabed a piece of rag and used it to put a heavy coat of neutral shoe polish on the rear of the action (anywhere that I thought could possibly get Devcon on). I also went to lengths of putting modelling clay into the action so that the epoxy wouldnt run inside. I've never used this epoxy before, so I didnt know how runny this stuff would be.



Notice that I stuffed the holes on the action with shoe polish where the rear of the base mounts too. I also loaded up the rear two screws. Once the shoe polish dried, I polished it in, then put another coat and waited for that to dry; I polished in this second coat as well so that it wouldnt create any seating issues.

Next I needed to prep the scope base. I grabed my 180 grit sand paper and lightly sanded the rear of my base where it makes contact with the action. I made sure to scratch away all of the blueing, but alo not changing the contour of the base. Do not over sand, just scruff it up so that the Devcon has something poreous to grab onto and afix too.



I also put shoe polish on the rear half of the base (make sure NOT to get any on the surface that makes contact with the action) to make sure that I didnt get any Devcon permenantly fixed to it where I didnt want it to be. I used some Q-tips to load the screw holes up with shoe polish.

Next I mixed my epoxy per instructions on the tubes. I gave another quick, light sanding to the rear of my base and then rand an acetone soaked Q-tip over it to make sure it was nice and clean. Once it dried, I smeared the epoxy over the preped surface of the base, making sure to not get the stuff in the screw holes (I tried hard as hell to keep the putty away from the holes so that the threads on my screws wouldnt 'accidentally' pick any of it up and screw me ... I didnt trust the shoe polish 100% on the screws).

Once I had the epoxy where it needed to be, I turned my base right side up, slide all 4 screws into their holes, and heald the base above the action so that the epoxy wasnt touching yet. I then started the front two screws so that the base was somewhat aligned, and then I started the rear two screws and kept screwing them in untill the epoxy began to touch the action.

Once some of the epoxy touched the action, I didnt want to screw the rear two screws in any further as I was afraid of carrying some of the epoxy down into the screw holes and permenantly welding those fuckers in there. I tightened the front two screws down to 15 inch/pounds and it sucked the base to where it needed to be.

Remember, I am trying to "build up" the rear of my base, so I didnt want to have my rear screws tight at all, I wanted the rear of the base to float where it was. My front two screws were torqued properly so it would set the height for the back.





Once the base was seated I took some Q-tips to clean up the overflow seaping out the sides.





All of this was done while my barrel was in the padded vice so that I had a steady surface to work with. I didnt want the action to accidentally roll over while I was trying to seat the base. I left the barrel like it was for about 2 hours.

After two hours I backed out the rear two screws and cleaned off all the gunck that was on them. I then grabed one of my skinny punches and pushed that through the rear two holes to clean out all the crap that was in the holes (I was paranoid that I got epoxy in there.) Once my butthole wasnt clenched in fear of f'ing up my action anymore, I still recoated my screws in shoe polish (because I'm anal) and screwed them back into the action, making sure that they were not snug at all.

The next morning I backed the screws out a little bit to make sure they were still good, and then threaded them back in a little.

Finally, later that night (almost 24 hours) I pulled all screws out and pryed up on my base, grabbing both ends and lifting with my fingers. I thougth I screwed up and welded my base to the action, but it finally came free.







I finally cleaned up my action and the base, checked for fitting, degreased everything, then used blue loctite on my screws, and torqued them all down to 15 inch/pounds.

This was a lot easier than I had thought, and everything turned out well. I can now rest assure that there is no more stress on my scope base.

Hope the pictures helped some of you!
 

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Maybe a dumb question, but is there something special about shoe polish? At work we use several different release agents, including; silicone grease, silicone dry lube (spray), and 3M car wax. Isn't shoe polish basiclly wax ?
 

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Ok, am I just lucky? I just tried tightning alternating ends on my 700 using a badger ordinance 1 piece 20 MOA rail...... no play or gap whatsoever. Could this be a "convex" condition of the angles from the mount points "tensioning" the steel rail? I have not fired this weapon yet, I'm just curious if I would benifit from bedding both points lightly anyway? Or is this a case of if it ain't broke don't fix it? thanks
JB
 

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I have heard about bedding bases, but have not seen anyone actually do it. I have probably mounted around 300 scopes for myself or for others, that included re-mounts and if you are using quality mounts, such as Warne or Talley, which fits the rifle receive to perfection, I personally cannot see the need, nor do the rifles with their accuracy. Still, if it makes you feel more secure about your mounting job, that is all that counts.
 

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No doubt it stiffens the action further. The question is whether does it need to be any stiffer. I have plenty of rifles shooting at or less than 0.5 moa at 100 yards, which is accurate enough for my needs. I could try placing one piece bases on them and re-mounting the scopes and see if accuracy improves or worsens. It would be interesting, but I would rather be hunting. In the off months it might be interesting to try with a couple of rifles of different brands.
 

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wow, is it the base or the gun thats out of wac?
if its the gun then a to pece mount set up can not be adjusted witch inturn means your scope is binding --- not good---
personaly i am going to use a one peace, do the beding and also dowal pin it front and back for a zero movement fit
thanks dude that is awsome info i never thought of that,
it just goes to show, pay atention to detail :D
 

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man I was looking for this for at least a month, how is it not in the DIY area?
 

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Very nice right up and it was just what i was looking for. I read another post on here about how to check to see if your scope mount needs to be bedded, I think it was under the Optics section, but I could not find a post where someone had done this. I think I might try it!
 

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could you not send in your action to your gun smith to have him mill the top of the action for trueness then the two surfaces would mate, it should only be a few thou out and then he could make you front and rear dowels for precice allignment?
 

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I was waiting for a scope I had on order and once again spent to much time reading the forums.

I bought a 20 MOA rail for my Savage and decided to see how much space was under the rail using a feeler gauge. With the front screws tight I could slide a .003 under the rear most screw and I'm sure it would have taken a few more.

With the rear screw tightened down I didn't have to use a feeler gauge. There was alot of space under the front. I took a 6' ruler and put that on top of the receiver and could see where the back part of the receiver had a little slope to it.

I decided to give the bedding a shot using available materials I had in the garage and kitchen. For the most part it was pretty easy. Scared me some but it worked out pretty good.

I pretty muched used the procedure at the beginning of the tread but had a bunch of different materials.

I down loaded a tech sheet for the permitex cold weld I had and used mineral spirits to clean up the epoxy.

I didn't have any Neutral shoe polish so I tried some brown and didn't like at that all. I went rummaging around in the kitchen and found some canning wax and that worked great. Its already dry and fairly hard so you can just rub it on and polish it up and your ready to go. I did use a couple of coats but easy to do and no waiting.

I didn't have any modeling clay so I tried to push the wax into the screw holes and that worked OK but I figured I could do better. I woundered around for awhile and found some plumbers putty and used that. Fantastic stuff.

I wanted to get the rear end screwed down but was worried about the screws getting glued into the action. I went back into the house and came back out with a hair dryer. I heated up the canning wax abit and then ran the screw treads into the wax and let the wax dry on the screw.

After I had the rail bedded and torqued the front screws down I ran the front rear screw in and tightened it down. I did loosen and retighten it a few times so it wouldn't seize on me.

I had quite the assortment of stuff out but I didn't have to order anything and it worked great.

I was a little worried I might have to beat the rail off but when I took the screws out this morning the rail basically fell off.

So much fun I'm going to do my 0 moa rail too.
 

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Glad I found this info. I just got the base and rings for my 700P and sure enough checked it. Slight gap in the rear when front screws are tightened. Being the scope I am putting on now is not the one that will stay on this rifle I chose to mount it just so I can hit the range. But if I get the vertical stringing I will know right where to start. Thanks for all the tips and photos.
Don
 

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First time doing this, I bedded the rear part of the base today. All of the open gap in the rear is gone now. I should have a good solid mount to the receiver now. Pretty happy with the way it worked out.
 
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