I have just had my 700 barrel threaded for a mod and there were some frightening issues when we tried to align the barrel to the chuck.
With the action in the chuck there was 3/8" difference from the action to the end of the barrel. We managed to get the gun deeper into the throat to allow the cutting to be concentric.

Unfortunately we did not notice if the alignment was out vertically (throw the bullet up or down) or left to right.

Should I be concerned?? I expect the true line is through the bore to the bolt, but 3/8" is a big difference.

If it is side-side out, would this not cause a crossover say from a 100 yard zero to 200 yards (left to right)

quote:

Originally posted by Johnny foreigner:
I have just had my 700 barrel threaded for a mod and there were some frightening issues when we tried to align the barrel to the chuck.
With the action in the chuck there was 3/8" difference from the action to the end of the barrel. We managed to get the gun deeper into the throat to allow the cutting to be concentric.

Unfortunately we did not notice if the alignment was out vertically (throw the bullet up or down) or left to right.

Should I be concerned?? I expect the true line is through the bore to the bolt, but 3/8" is a big difference.

If it is side-side out, would this not cause a crossover say from a 100 yard zero to 200 yards (left to right)

I would like to help you but I don't understand what you are saying or asking. Could you please rephrase it a little clearer? What is a "mod" and what is the 3/8" reference again?

If you are speaking of a sound moderator installation, I can understand what you are asking....

But, I sure wouldn't do it by putting the action (body) in the chuck, and then threading the barrel some 20-odd inches away. I'd remove the barrel from the action, center up the barrel, then cut the threads for the moderator.

If your spindle bore is large enough, I'd put the barrel through the spindle bore, with just a couple or 3 inches protruding from the chuck. Should be no problem at all centering that.

If you have to do it between centers, it would still be much simpler with the barrel out of the body (action)....at least so far as centering it all up.


As to the "crossover" to which you refer, it should have no influence at all on the striking point of the bullet at various ranges. The bullet is not leaving the muzzle at different points depending on the range at which it will eventually strike. So long as it leaves the muzzle consistently, it should shoot consistently.


The important reason for having the barrel and moderator aligned on the same axis is to keep the bullet from twanging against the Belleville washers or whatever else constitutes the guts of the moderator. Any contact there definitely WILL destroy accuracy at all ranges.

I would like to help you but I don't understand what you are saying or asking. Could you please rephrase it a little clearer? What is a "mod" and what is the 3/8" reference again?[/QUOTE]

I have checked this again and, if you remove the stock and take a cetre line from the two scope base screws, the centre of the barrel is 1/4 of an inch off to the left of centre. When in the stock, this is reduced to about 1/8th of an inch. I would have thought if the scope mounts were not in line with the centre of the barrel, it would change the point of impact left or right of the target over distance.
By mod I meant a moderator.

What AC has said is a good point, but unless I am mistaken, most of the gunsmiths I have used have not removed the barrels of any of the guns before threading for a moderator or muzzle break. This could be me being missinformed.

Daft question, but how do you remove a barrel from a 700? Are there special tools available.

Thanks for your help.

quote:

Originally posted by Johnny foreigner:
I have checked this again and, if you remove the stock and take a cetre line from the two scope base screws, the centre of the barrel is 1/4 of an inch off to the left of centre. When in the stock, this is reduced to about 1/8th of an inch. I would have thought if the scope mounts were not in line with the centre of the barrel, it would change the point of impact left or right of the target over distance.
By mod I meant a moderator.

What AC has said is a good point, but unless I am mistaken, most of the gunsmiths I have used have not removed the barrels of any of the guns before threading for a moderator or muzzle break. This could be me being missinformed.

Daft question, but how do you remove a barrel from a 700? Are there special tools available.

Thanks for your help.

What's your gunsmith telling you? Sounds like either the barrel is out of whack, or the threads in the receiver are out of whack. But you won't know unless you pull the barrel and check each component separately.

The barrel really needs to come off the action in order to do the job correctly. For the sake of safety and accuracy, the bullet has to fly through the center of the moderator, or, muzzle brake.

www.brownells.com sells special tools for pulling Remington 700 barrels. Doesn't your gunsmith have these tools?

It isnt uncommon to find actions that are machined inaccurately.

When a gunsmith blueprints an action to make an accurate rifle one of the key things is to ensure that the thread in the action is parallel to and concentric with the action body and bolt way. It is common to slightly recut the thread to ensure this and to square off the action face.

Then when a barrel is screwed in it should end up pointing the same way as the action!

Assuming your sight base screws are in line with the action you have another problem.

If when putting the barrelled action back in the stock that alignment changes by 1/8" it indicates the stock is putting tension on the barrel. Freefloating by opening up the barrel channel should fix this.

If your gunsmith doesnt understand this maybe you should think about changing 'smiths?

Find one who builds target and benchrest rifles.

As others have said there is no need to remove the action from the barrel to machine the muzzle. The stripped of bits action should fit in the bore of the headstock in any reasonable size lathe. If your gunsmiths lathe can't accommodate it any reasonable machine shop can do it for you. There's nothing to it.

By the way it is also unfortunately quite common to find barrels where the bore is not centred to the circunference of the barrel (concentric). Make sure the thread is concentric with the bore, not the barrel circumference. A 4 jaw chuck helps here.

I have seen a Ruger 10-22 with a sinecer thread machined 50 thou off centre to the bore. It shot patterns, not groups.