700 Barrel Questions

[maxscm]

As you can tell by my questions I'm not a Gunsmith.
My gunsmith's unavailable at the monment, so I'll ask some questions here.
Here's 3 - 243 chambered Barrels threaded for the rem 700 actions.
The 2 on the left are Factory take off's and the one on the right is Custom.
Why did they cone the one on the right?
Do you have to have the bolt face of a 700 action Bolt "Coned" to properly headspace that particular barrel or can you head space to a Standard Bolt?



more pics, notice the new unfired 243 Lapua brass in the coned barrel on the right. It doesn't seat as deep as the 2 on the left.



That's is New Unfired Lapua 243 Brass in each chamber.

 

[butchlambert]

The one on the right is for a cone bolt. Has nothing to do with headspace.

 

[Erik Cortina]

Butch, notice the flat before the cone starts. Also, in a coned bolt action, the back of the case usually is flush with the tenon. Looks to me like it was chambered for a Remington 700 but the "smith" did not recess the tenon for the bolt. Looks like he faced the tenon to fit bolt nose and coned the rest.

Maxscm, are you sure these all came from Remington 700's?

 

[butchlambert]

Erik,
It looks exactly like the barrels from my very early Stiller Diamondback.

 

[Erik Cortina]

Erik,
It looks exactly like the barrels from my very early Stiller Diamondback.

It might be, maybe the OP knows what action it was on.

 

[dmoran]

It looks odd to me also....
Never seen a "flat to cone" (not sure what to call it) breach for a coned bolt before, just 30-deg. compound feeds all the way across.

Butch - what is the bolt nose shaped like on your earlier Diamondback?

Donovan

 

[jscandale]

I put a new barrel on a friends HS Precision that had a similar cone. Pain in the butt to do. Also looks like the thread pitch is different in the pic. Maybe just an optical illusion.



JS

 

[butchlambert]

It looks odd to me also....
Never seen a "flat to cone" (not sure what to call it) breach for a coned bolt before, just 30-deg. compound feeds all the way across.

Butch - what is the bolt nose shaped like on your earlier Diamondback?

Donovan

The bolt nose was flat across the counter bore for the cartridge and then coned. Jerry quit making them that way. On my print from Stiller for my Diamondback PPC called for a flat at .580 diameter and then a 14deg cut for the cone from there.
I hope this isn't too confusing. It looks more like maxscm than JS barrel. Stiller used a 1.0625X16TPI.

 

[X Ring Accuracy]

You can cone the breech for feeding if you think its an issue. Trying to mate a Rem with a Win in my opinion. Don't see the need for the cone for feeding and it looks bastard LOL. Probably shoots fine.

 

[maxscm]

Thanks for the responses fellers. Each of the barrels were removed from Rem 700 Actions. The threads looking different is an optical illusion. The Coned barrel is an HS Precision chambered in 243. And what I'm asking is can a flat nosed factory 700 Bolt be used with the coned Barrel (properly headspaced of course) and if not why?

 

[maxscm]

I put a new barrel on a friends HS Precision that had a similar cone. Pain in the butt to do. Also looks like the thread pitch is different in the pic. Maybe just an optical illusion.



JS

Did you Cone his Bolt???

 

[jscandale]

Yes, I did cone this barrel to accept an HS Precision bolt action.
You absolutely can use a coned barrel with a flat bolt as long as you machine a mating flat on the base of the cone in order to give the case all the support possible by using proper minimal clearance from the bolt nose to the barrel.

The picture on that HS barrel has about .012" from the flat to the mating flat on the bolt if I remember right. The only thing that you will lose by coning a barrel to accept the standard rem bolt is the famed "3 rings of steel" which adds an additional layer of protection to slow down hot gases in the event of case failure.

JS

 

[maxscm]

Yes, I did cone this barrel to accept an HS Precision bolt action.
You absolutely can use a coned barrel with a flat bolt as long as you machine a mating flat on the base of the cone in order to give the case all the support possible by using proper minimal clearance from the bolt nose to the barrel.

The picture on that HS barrel has about .012" from the flat to the mating flat on the bolt if I remember right. The only thing that you will lose by coning a barrel to accept the standard rem bolt is the famed "3 rings of steel" which adds an additional layer of protection to slow down hot gases in the event of case failure.

JS

thanks JS that was the answer I inquired about.

 

[jscandale]

maxscm,

You probably are already aware of this, but in the strict interest of safety I just want to stress the following:
**Be sure that when you are head spacing the barrel to the bolt, you are not getting a false reading from the front of the bolt lug contacting the cone rather than the headspace gauge contact or mating surfaces.**

Good luck with your project,
JS

 

[maxscm]

Good Advice,

thank you,

maxscm

 

[TAJ45]

I thank everyone for their contributions to this thread and site in general. Just too much good information to be assimilated - but I'm trying.

 

[Rustystud]

The coned breech defeats the Engineered and Patented "Remington three rings of Steel". Yes, it may work but it was not designed to be done this way. If there was a case head failure and someone was injured or killed the lawyers would have a "hay day" with the smith who did this work. If the smith has liability insurance I would bet they have a disclaimer for not using the "existing engineering and design". I would bet the H.P. White Laboratories would not sign off on this modification as being safe.
Nat Lambeth

 

[maxscm]

The coned breech defeats the Engineered and Patented "Remington three rings of Steel". Yes, it may work but it was not designed to be done this way. If there was a case head failure and someone was injured or killed the lawyers would have a "hay day" with the smith who did this work. If the smith has liability insurance I would bet they have a disclaimer for not using the "existing engineering and design". I would bet the H.P. White Laboratories would not sign off on this modification as being safe.
Nat Lambeth

Thanks for the contribution Nate.
If this HS Precision Barrel with the cone breech was in your shop how would you mate it to a 700 action.??

 

[NateHaler]

I bet he'd set it back, meaning cut off the coned part of the tenon, machine the barrel to lengthen the tenon to the proper spec, thread the new full tenon, and then rechamber.

 

[butchlambert]

I'm sure he would do as I if fitting to a Remington. Machine the tenon as done by the factory.
Now if it were an early Stiller I would machine it to fit the contour of bolt nose. A lot of actions have coned bolts including most of the customs.