Friend Paul Tolvstad

Bill Calfee

Gun Fool
Friend Paul Tolvstad

Friend Paul Tolvstad:


Just talked to J-Pat....


A corrugated 8 for Foster's XP:


1.150" at the breech end for four inches, then stepped down to between .800"-.815" for the balance of the barrel...


Your friend, BC



I know Foster is cited..............................
 
8 groove

Just have to lap it yet.
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Friend PT

Just have to lap it yet.
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Friend PT:


I don't envy you........


Especially having to lap that big end for the giant centerfire barrel thread of the XP....


It's tough enough to keep from washing out the breech end on a straight profile barrel, like an .850" or .900:, for example..


But having to deal with that giant breech end, man that's a hassle.....


This is why years ago the world of RFBR went to .750" diameter barrel threads.....




The one consolation, is, you're lapping a corrugated 8, and I've yet to see one washed out in the breech end from the taper lapping...


Course, I've not seen a corrugated 8 with the giant breech end, either.....


PT, knowing you, my gut tells me this barrel will be lapped perfect......


Although I absolutely do not envy you..........taper lapping, properly, ain't pleasant........


Good luck....


Your friend, BC


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PS:


I'm still thinking about what Tom Wilkinson said about the wind bucking ability of the corrugated 8...


And Tom has been pretty much a ratchet man, and for good reason, since he's had so much success with ratchets.

So the corrugated must have really impressed him....

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One other point.....

Just have to lap it yet.
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One other point...


Friend PT, I wish every interested RFBR shooter could slug this barrel before you lap it.


They would immediately realize why the world of serious RFBR accuracy got away from actions with those giant barrel threads years ago.


Can a barrel with the giant barrel thread be produced that's competitive at the big national events?


The answer is, yes, occasionally......"occasionally" is probably a generous adverb to use here, though....




The chances of getting a killer RFBR barrel are so much greater with straight profiled blanks, since they're so much easier to taper lap properly, without washing out the breech end of the blank.


Your friend, Bill gun fool Calfee


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PS:


PT, my new MD-PAS pistol would take a straight profile corrugated 8 between .800"-.815" in diameter.......


Cough-cough, sneeze, double sneeze, wink-wink................


And it wouldn't even have to be lapped.....I'd gladly relieve you or Dan of that headache, and lap it myself..........

And I'll pay the full price for it that you normally charge when you guys do the lapping...



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Friend PT

The one for Foster has just under 4" of straight and is 27" long blank


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Friend PT:


Thank you.


PT, I'm going to have to let Foster make the decision whether to fool with this blank or not.....


Your friend, BC


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PS:


PT, to do what we started out to do with Foster's pistol, requires a full 4 inches at the breech @ 1.150" , then the balance of a 28 inch blank, or longer, to be straight profiled between .800" and .815" in diameter.


So......................


Foster needs to make the decision as whether to fool with the 27" blank, or not...bc


 
Friend PT

I only have 27" blanks. I haven't final lapped this yet that's why I asked.


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Friend PT:


If we were dealing with a straight profile .800"-815" diameter blank, we could get what is needed from a 27 inch blank.


But.......................


We're dealing with the giant barrel thread of the XP action.


So getting what is wanted from a 27 inch blank will be much tougher....


Is it possible?........Yes.


But to do so will require your lapping to be such, that the crown will be at the exact proper location, and likewise the chamber.


There would be no room for error using a 27 inch blank, which puts a big burden on the person doing the lapping....


So it's up to you and Foster.........


Your friend, BC
 
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