Breech face detail on P-14 barrel

[RP3543]

Need some assistance re-barreling a P-14...
Does anyone know the easiest method for machining the extractor clearance
on the breech face of a P-14 barrel.  It appears to be a rather complicated set-up.
I have a lathe/Mill/Shaper and tooling is not a problem, it's just not obvious to me how this
should be attempted.
If anyone could recommend a book or DVD or give me a hint, I would appreciate it.
TX!
Bob

[John Traveler]

I am looking at a barrel stub from a P-14 barrel as I write this.  The original extractor cut appears to be broached, or cut with a shaper.

The cut is easy to duplicate using a scriber to mark the outline, hacksaw, and a mill file to cut it.

If you have a vertical mill, it will be even easier.  Clamp the barrel with the bore horizontal, and use a woodruff keyway cutter and approach from the side. 

This requires that the barrel be angled so that the completed cut duplicates the original breech.

HTH
John 

[RP3543]

John,
Thanks for the reply!
I think your talking about the .275" wide slot that angles down thru the threads.
I plan on using my shaper to make that cut.  The detail I'm talking about is on the face of the
breech end of the barrel...
(See attached pdf sketch - if it's attached, it may not show up)
What the sketch illustrates (I hope) is the clearance cut for the nose of the extractor.
If you look directly at the face of the breech, with the .275" cut at 3 O'clock, the extractor clearance
runs from about 8 O'clock and terminates at the .275" cut.  It appears to get progressivly deeper as
it goes around the face of the breech and it looks like it's about 3/16 wide.
I have a 1917 Eddystone barrel with this detail but I don't have a P-14 barrel to look at.
I would like to fit a .405 Win. barrel to the P-14 action that I have so I need to know how critical this
clearance is.  Maybe I can shorten/grind the extractor nose down? (I'd rather not)
Any thoughts you may have on the subject would be very helpful!
Thanks agin for your reply and your time...
Bob

[John Traveler]

Bob,

I just looked at two other Remington/Eddystone P-14 barrel breeches, and both have that "extractor clearance cut".  It appears to be cut with an end mill cutter and the barrel breech partially rotated around the bore axis, requiring a special fixture.  The first barrel stub I examined had just a shallow counterbore on the breech face, and the extractor slot.  It is not an extractor cut, but rather a channel designed to divert breech gases in case of a ruptured cartridge case.  This action was designed almost 100 years ago, and cartride brass metallurgy was not what it is today.  Cartridge case failure was much more common then in service rifle ammunition.

I don't think that circular breech cutout is even necessary, and I know of no gunsmith that duplicates this cut in rebarrelling the P14/M1917 action.  The P14/M1917 extractor is in a fixed position relative to the bolt.  It does not rotate with the bolt face.  I don't think you need to shorten the extractor to clear the barrel breech.  You may need to stone or adjust the extractor hook to reliably engage the .405 Winchester rim and case diameter.

Let us know how it works out!

HTH
John

[RP3543]

John,
Your absolutly right!  The extractor does not rotate with the bolt so there's no need for a clearance
cut there.  What the @#$%^ was I thinking!  Thanks for pointing that out, sometimes I think too much.
I've got the action and a barrel and I'm in the process of planning this job out.  There's alot of stuff to do
and I want to make sure I have at least the semblence of a plan before I get started.  I'll be sure to post a picture
when I'm finished
Thank you for all your advice, I really appreciate it!
Bob

[Brithunter]

Ahh you got your thinking mixed up.

   The clearence groove is for the left hand extended bolt lug which does rotate.

  Checking on a BSA barreled P-14 it has the rotary groove but comparing a Century Arms re-barreled P-14 it does not have it. So the BSA has a better supported case as the Century Arms one must have more clearence as on the P-14's the left bolt lug protrudes forward of the bolt face or rim which supports the case rim.

[RP3543]

Brithunter,
Thanks for the reply!
So, in your opinion, should the relief be put in the breech face and, do you have suggestions as to how this could be done?
Or...
Could I turn the lug face back such that it's flush to the rim and forget the relief in the barrel?
I'm not holding anybody to anything, just looking for ideas...
Thanks again!
Bob

[Brithunter]

Well Century when they rebarreled lots of these did not alter the bolt lug and also they did not machine the radial groove for clearence. What they did was set the head space in such a way that the extended bolt lug does not touch the breechface. This means that there is a little more clearence and unsuported case than the P-14 originally was designed to have.

  The breechface is cut back enough to miss the bolt lug  then the headspace is set. Yep that sounds better. The extended lip on the left lug is about 0.027" and the depth in total to the bolt face is 0.057" so it should be possible to have a flat breechface and yet still set the headspace right. Good luck with it.