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Enlarge 224 to 308 for piloted countebore?

Grizzlypeg

Aluminum
Joined
Aug 20, 2012
Location
Canada
Is it at all practical to consider enlarging the initial section of a 224 bore (say 219 actual) to 308 (.300) so that I can use a piloted counter bore that I already own (made for .300)? If so, what would be the best way to do it accurately?

After its all done, that section of bore get oblitered when I predrill it and use a boring bar to straighten it. So it does no harm as far as I can see to bore it out to .300 to allow the piloted counterbore to be used. But how to do it reasonably accurately?

(EDIT: This is all work at the muzzle using a PTG bolt nose counterbore

.705 Counterbore Without Step - Pacific Tool and Gauge

made for roughly .300 and up pilots)
 
Is it at all practical to consider enlarging the initial section of a 224 bore (say 219 actual) to 308 (.300) so that I can use a piloted counter bore that I already own (made for .300)? If so, what would be the best way to do it accurately?

After its all done, that section of bore get oblitered when I predrill it and use a boring bar to straighten it. So it does no harm as far as I can see to bore it out to .300 to allow the piloted counterbore to be used.

So you have no way to single point to cut it? I see no problem if you cut that part of the muzzle off or bore and make a recessed crown.
 
I could single point cut the bolt nose recess that this counterbore makes, but it worked so slick on my 308 that I would like to use it on my 223, but of course the pilot is too large. This particular brand, PTG doesn't permit a pilot for .223 to be used on it. I think it only goes down to .300. So if I could see a way to make the .219 bore opened up to .300, even if it lost .001 concentricity in the process, I could use the counterbore tool. My apologies if I am misnaming this tool. Its a piloted tool that makes the .705 for a Remington bolt nose at the breach.
 
I just cut my counterbores with a boring bar, usually after the chamber is nearly complete. If you chamber first, there's not much left to cut.

Sent from my Pixel 2 using Tapatalk
 
Dave Manson makes the counterbore tool with a #1 spindle for .22 cal.

What else should we spend our money on, but more tooling?

Besides, boring to within a thou just ain't in my skill set. The form cutter faces the barrel end and puts a radius on the counterbore entrance.

Time is $$, the tool makes it fast, and perfect.
 








 
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