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Truing a 700 action

 
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  #1  
Old 12-04-2013, 08:41 AM
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Join Date: Jun 2013
Posts: 90
Truing a 700 action

OK a buddy of mine and I have been talking for a long time about this and would like some more input.
We are talking about truing a out of the box Remington 700 for hunting, not a brench rest rig.
We both agree that the treads need to be cut square to the bore of the action and the lugs cut/lapped, and the face of the action cut square.
The question comes with the bolt. We both agree the lugs should be lapped to make 100% contact with the action.
Now for the bolt face, this is where we seem to get confused. The bolt face can be trued (or not) by cutting it on the lathe or by the jig that screws into the face of the reciever, or left alone.
The bolt wants to lay in the bottom of the action naturally and we know that the action can have a tapered race way. We also know that sear spring can push up on the back of the bolt when it is cocked and ready to go.
If the bolt faced is squared in the lathe, it is squared to itself but when it is in battery, there is a chance that the face is not square to axis of the action/barrel.
If it is squared using the jig that screws into the action threads, it looks like the bolt face might be closer to square to the center line of the barrel as the bolt is squared in its "in battery" location.
If you leave it alone does it really matter (in a hunting rifle) because if everything is perfect and square you still have .006 or more clearance between the bolt and action.

Thank you for your input

John
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  #2  
Old 12-04-2013, 03:31 PM
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Join Date: Jul 2004
Location: Texas
Posts: 5,421
Re: Truing a 700 action

Quote:
Originally Posted by Clay Target Guy View Post
OK a buddy of mine and I have been talking for a long time about this and would like some more input.
We are talking about truing a out of the box Remington 700 for hunting, not a brench rest rig.
We both agree that the treads need to be cut square to the bore of the action and the lugs cut/lapped, and the face of the action cut square.
The question comes with the bolt. We both agree the lugs should be lapped to make 100% contact with the action.
Now for the bolt face, this is where we seem to get confused. The bolt face can be trued (or not) by cutting it on the lathe or by the jig that screws into the face of the reciever, or left alone.
The bolt wants to lay in the bottom of the action naturally and we know that the action can have a tapered race way. We also know that sear spring can push up on the back of the bolt when it is cocked and ready to go.
If the bolt faced is squared in the lathe, it is squared to itself but when it is in battery, there is a chance that the face is not square to axis of the action/barrel.
If it is squared using the jig that screws into the action threads, it looks like the bolt face might be closer to square to the center line of the barrel as the bolt is squared in its "in battery" location.
If you leave it alone does it really matter (in a hunting rifle) because if everything is perfect and square you still have .006 or more clearance between the bolt and action.

Thank you for your input

John
Everything has to be squared to the center line.

The bolt is squared by turning the back of recoil lugs and the bolt face in the Lathe. Then the receiver face is squared and the recoil lugs are squared in the lathe at the same time. then we lap the lugs to seat them and polish the mating surfaces for smooth operation and extraction.

In order to be able to work the bolt there has to be some clearance between the bolt and the action,

Proper head space and a good chamber will solve any alignment problems due to this built in clearance.

In My Opinion, It does matter if the bolt is not square. The reason being, the bolt can move during firing and if it is not square to the recoil lugs , The bolt face can cock the case head several thousandths hurting accuracy and case life.

Note: If everything is not square it does no good to do some of it, and in some cases it can make the condition worse.

Just my opinion

J E CUSTOM
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  #3  
Old 12-06-2013, 11:46 PM
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Join Date: Nov 2013
Location: The South
Posts: 26
Re: Truing a 700 action

Quote:
Originally Posted by J E Custom View Post
Everything has to be squared to the center line.

The bolt is squared by turning the back of recoil lugs and the bolt face in the Lathe. Then the receiver face is squared and the recoil lugs are squared in the lathe at the same time. then we lap the lugs to seat them and polish the mating surfaces for smooth operation and extraction.

In order to be able to work the bolt there has to be some clearance between the bolt and the action,

Proper head space and a good chamber will solve any alignment problems due to this built in clearance.

In My Opinion, It does matter if the bolt is not square. The reason being, the bolt can move during firing and if it is not square to the recoil lugs , The bolt face can cock the case head several thousandths hurting accuracy and case life.

Note: If everything is not square it does no good to do some of it, and in some cases it can make the condition worse.

Just my opinion

J E CUSTOM
Good info here. Use the lathe. As for lug contact, anything 75% or better should be good.
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  #4  
Old 12-07-2013, 08:43 AM
Bronze Member
 
Join Date: Jun 2013
Posts: 90
Re: Truing a 700 action

So the way I see it, you have three parts, the receiver, barrel, and bolt and each has its own center line. The barrel and the action center line should be very close to each other by the very nature of how they are machined and put together. They may not be perfect due to the torque when the barrel is seated but will be very close.
The bolt center line does not have the same center line as the action/barrel due to the fact it has clearance and is most likely resting in the bottom of the action.

If I understand what you are saying, as long as the CL's are parallel and square to one another, that is what matters. Not trying to put words in anyones mouth, just wanting to make sure I am on the right page.

Thanks
John
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  #5  
Old 12-07-2013, 09:55 AM
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Join Date: Jul 2004
Location: Texas
Posts: 5,421
Re: Truing a 700 action

Quote:
Originally Posted by Clay Target Guy View Post
So the way I see it, you have three parts, the receiver, barrel, and bolt and each has its own center line. The barrel and the action center line should be very close to each other by the very nature of how they are machined and put together. They may not be perfect due to the torque when the barrel is seated but will be very close.
The bolt center line does not have the same center line as the action/barrel due to the fact it has clearance and is most likely resting in the bottom of the action.

If I understand what you are saying, as long as the CL's are parallel and square to one another, that is what matters. Not trying to put words in anyones mouth, just wanting to make sure I am on the right page.

Thanks
John

Not really.

If done right, all parts are on the same centerline (The Barrel bore center line is the one to work off of). If everything is done in the right order and held to the closet tolerances everything should be
centered.

Also the lugs should be in 100% contact and lapped for best performance.

A proper accurizing/Blue printing requires time and skill to do properly and a quality chamber and head space are also required in order to realize the potential of a blue printed action. also skill in loading and shooting are a must.

Accurizing is only one part of a fine shooting rifle and when done right the rifle will shoot almost anything well (Not finicky to different loads) and when the right load is found the accuracy can
be phenomenal.

This is one place that being Anal is a plus.

Just my opinion

J E CUSTOM
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  #6  
Old 12-07-2013, 11:55 AM
Bronze Member
 
Join Date: Jun 2013
Posts: 90
Re: Truing a 700 action

Quote:
Originally Posted by J E Custom View Post
Not really.

If done right, all parts are on the same centerline
J E CUSTOM
Please don't think I am arrgueing (just trying to understand), but how can the bolt be on the same CL as the action/barrel when it has .005-.006 clearance?
Would the CL of the bolt not be out by .003 (approx) but if done correctly is should be parallel and square?

Thank you for your time to teach me

John
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  #7  
Old 12-07-2013, 01:24 PM
Platinum Member
 
Join Date: Jul 2004
Location: Texas
Posts: 5,421
Re: Truing a 700 action

Quote:
Originally Posted by Clay Target Guy View Post
Please don't think I am arrgueing (just trying to understand), but how can the bolt be on the same CL as the action/barrel when it has .005-.006 clearance?
Would the CL of the bolt not be out by .003 (approx) but if done correctly is should be parallel and square?

Thank you for your time to teach me

John

You are not being argumentative, just asking questions.

If everything is machined true to the centerline of the bore and the head space is .000 to .001 (I like slight pressure on the case head) -.0005 to .000 so it squares everything up before firing, the center line of the bolt is very very close unless the bolt face is to large allowing the bolt off center by .001
or .002 thousandths. Even if it does the bolt face will be square to the bore and the cartridge will still be on the same center line as the bore and will not move upon firing.(Common with poor fitting parts).And is Very important for the best accuracy.

So the fact that the bolt could be several thousandths below the center line of the bore, there is no way of measuring it and no need to if everything is fit as near perfect as possible. To be a perfect fit in every way you couldn't have any clearance between the bolt and the receiver and it would not be
functional. The trick is to get everything as close to perfect as possible but still be functional.

A bolt that has .005 + clearance should be replaced with a over sized bolt and the receiver reamed to fit within a couple of thousandths.

If everything is done this way the bolt will have a tendency to find it's way to the same spot, Square and centered every time.

So I have to agree with you that It is not perfect but done right as near as possible.

A "proper" Blue print will help accuracy, consistency, wear,and improve brass life so in my opinion it is not only important but a must if you are looking for the ultimate accuracy.

Hope this helps

J E CUSTOM
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