Truing top of Rem 700 receiver

[Gil P.]

What's the proper way to true the top of the Remington 700 receiver and align the base holes?

Does the top of the receiver need to be welded up first?

Can anyone recommend a gunsmith to perform the service?

 

[akajun]

are you talking about putting the receiver on a mandrel through the bolt raceway and cylindrical grinding?

 

[Gil P.]

are you talking about putting the receiver on a mandrel through the bolt raceway and cylindrical grinding?

If I'm understanding you correctly, I am not talking about truing the inside of the action (raceway area) but the top of the action where the scope base sits.

 

[akajun]

No i'm talking about putting the receiver on a tightfitting mandrel that slides in the raceway and then putting it on a cylindrical grinder or surface grinder and grinding the OD of the receiver true to the ID of the raceway. That will be expensive, in fact Id say that by the time you take that action and have it traditionally trued, then cylindrically grind the OD you will have far exceeded the cost of a custom action that is already true.
Lots of people have lathes or blueprinting tooling so traditional trueing is not that expensive. But what your wanting to do requires specialized tooling to do a good job that most gunsmiths dont have. Yes I know you could do it with a lathe either with a tool or toolpost grinder or on a mill in a dividing head but it would not look as good and would require a lot of setup.

 

[Dusty Stevens]

Trying to justify this work even at free

 

[Gil P.]

No i'm talking about putting the receiver on a tightfitting mandrel that slides in the raceway and then putting it on a cylindrical grinder or surface grinder and grinding the OD of the receiver true to the ID of the raceway. That will be expensive, in fact Id say that by the time you take that action and have it traditionally trued, then cylindrically grind the OD you will have far exceeded the cost of a custom action that is already true.
Lots of people have lathes or blueprinting tooling so traditional trueing is not that expensive. But what your wanting to do requires specialized tooling to do a good job that most gunsmiths dont have. Yes I know you could do it with a lathe either with a tool or toolpost grinder or on a mill in a dividing head but it would not look as good and would require a lot of setup.

Thank you, now I understand. Would truing the ID of the raceways have any benefit? So long as the lugs are square to the abutments and barrel, I don't understand how it could improve accuracy. Can you explain that to me?

 

[BoydAllen]

One thing that can be done is to make bases on the receiver. The blanks are contoured to the action, mounted, the action is aligned on the mill, and the tops of the bases machined. For a bolt together solution, the Burris rings that have plastic inserts have worked very well for me.

 

[davidjoe]

I have put a good number of Badger and Nightforce picatinny rails on 700 actions with no perceptible alignment issues in the screws, or scope windage surprises upon sighting in. In setting them in place before securing them, unsecured floated fit was also just right. I’m surprised there’s a suspect action out there, but they could always be torqued out of shape I suppose in barrel swaps.

 

[carlsbad]

Can't figure out what you're trying to achieve.

 

[gunsandgunsmithing]

If you're trying to align the base screws, I just mill, not drill, the holes for 8-40 screws rather than the std 6-48. If that's not enough to fix alignment, get a different action. Vertical alignment can be done by bedding the bases or as Boyd said, machining the tops to be perfectly flat. This is pretty simple gunsmith stuff unless you're talking about something else, entirely.

 

[paperpuncher]

If I'm understanding you correctly, I am not talking about truing the inside of the action (raceway area) but the top of the action where the scope base sits.

You could have the scope base holes opened up to 8-40 When doing this you could adjust the screw position if they are not in the correct place or spaced incorrectly. As far as reprofiling the exterior of the action( I can only assume the reason is to match the scope base), there are better ways to achieve this. It is common to bed the scope base to the action similar to the way an action is bedded to the stock. After bedding the base can be attached solidly and without stress

 

[akajun]

Trying to justify this work even at free

Hahaha yep, someone gave me a bunch of military Mausers with bad pitting, did it on my mill with a dividing head on a mandrel to clean them up and remove the stripper clip hump. Just did one after the other one afternoon so I didn’t mind the setup work. Surface finish was rough but a after a little shoeshine with Emory cloth and a blast and park they cleaned up. A friend did this on some Katrina flood guns that had sentimental value in his lathe with a tpg , said they cleaned up ok and that he noticed out of roundness that was removed. Was there any Benicia other than cosmetic? Probably not

 

[Ledd Slinger]

If I'm understanding you correctly, I am not talking about truing the inside of the action (raceway area) but the top of the action where the scope base sits.

What???
You don’t true the top of the receiver. You bed the scope base rail to the receiver so they match.

700 has different heights and radii from front to rear. Truing the top of the receiver to match a scope rail would be a major PITA and you would probably still need to bed the rail to get a perfect match anyhow.

 

[Gil P.]

Thanks for the replys. I do bed the rear of my scope bases.

I was curious if it could be done, it seems like the easiest option is to align the base holes and bed the base.

 

[Ledd Slinger]

Thanks for the replys. I do bed the rear of my scope bases.

I was curious if it could be done, it seems like the easiest option is to align the base holes and bed the base.

Yes. But don’t just bed the rear. Bed all mating surfaces of the rail in front and rear.

 

[Gil P.]

Yes. But don’t just bed the rear. Bed all mating surfaces of the rail in front and rear.

What's the best way to go about bedding the front? When I bed the rear I apply epoxy under the rear of the base and tighten the two front base screws.

Is it the same process for the front, or should I start over?

 

[tobnpr]

Is it the same process for the front, or should I start over?

Yes, no different.
You're just filling in any gaps that might exist because of a slight difference in the radius of the receiver and that of the base.

 

[Gil P.]

Got it, so I'll just tighten the two rear base screws and bed the front.

 

[Ledd Slinger]

What's the best way to go about bedding the front? When I bed the rear I apply epoxy under the rear of the base and tighten the two front base screws.

Is it the same process for the front, or should I start over?

Same process. I apply release agent on the receiver, then bedding to front and rear of base. Place all 4 screws in the base and carefully “start” all 4 screws with a couple threads before fully lowering the base onto the receiver (not tightening any screws yet). Then tighten the front screws down with about 10 in.lbs so they are nice and tight, but not fully torqued. Then turn in the rear screws until the heads just touch and match up with the countersink holes on the base. This allows the rear to float, but ensures perfect screw alignment as the bedding cures.

Once cured, break base from receiver and clean off excess bedding and release agent. Then let base sit separated from receiver for an additional 24 hours to ensure full solid cure before installing it on the receiver with full torque specs. Don’t forget thread locker on the base screws

I use Marine Tex for epoxy on scope bases and kiwi neutral shoe polish for release agent. The reasoning for Marine Tex is the simple fact that it will have much less shrinkage over long periods of time. Maintains its initial cured state very well. This helps screws from coming loose later on when you don’t expect it. Still check them regularly tho

 

[Gil P.]

Awsome thank you. I'll get to it.