verifying freebore

[jsthntn247]

I know several rifles cut with the same reamer as mine. All of those guys freebore is around .040 shorter than mine. All of our headspace dimensions are the same. Does this mean my barrel diameter is on the large size?

 

[Jay Christopherson]

I know several rifles cut with the same reamer as mine. All of those guys freebore is around .040 shorter than mine. All of our headspace dimensions are the same. Does this mean my barrel diameter is on the large size?

How was it determined that their freebore is. 040" shorter than yours?

 

[jsthntn247]

How was it determined that their freebore is. 040" shorter than yours?

Same bullets, cases, and gauges being used. They are all within a few thou of each other and im 40k longer based off ogive and tip measurements when touching lands. Same reamer looks like you are questioning, 308 Ftr reamer.

 

[hogpatrol]

Are you sure it's. .040 and not .004? What method are you using, the Hornady unit or the stripped bolt & bolt click method?

 

[jsthntn247]

Nope its .040. I know 2 other people on here that used different FTR reamers and their dimensions match the other guns and mine is about the same length longer. I've done the stripped bolt method, hornady inserts with stoney point, and shining a bullet with steel wool and seating it looking for land marks, mine is allot longer for some reason.

 

[savagedasher]

Doesn't free bore change with every shot ? If you use the same method every time you should be able to see the change . The correct method is the one you use .
Larry

 

[hogpatrol]

Nope its .040. I know 2 other people on here that used different FTR reamers and their dimensions match the other guns and mine is about the same length longer. I've done the stripped bolt method, hornady inserts with stoney point, and shining a bullet with steel wool and seating it looking for land marks, mine is allot longer for some reason.

Have the other rifles been borescoped? Are their chambers squeaky clean with no carbon ring? I believe something is amiss here in the measuring process.

 

[Jay Christopherson]

Doesn't free bore change with every shot ? If you use the same method every time you should be able to see the change . The correct method is the one you use .
Larry

Not unless you are capable of measuring freebore to something like .00001" or smaller. No person or method I am aware of is capable of that.

 

[savagedasher]

Not unless you are capable of measuring freebore to something like .00001" or smaller. No person or method I am aware of is capable of that.

Not or do I care . After it is shot 100 time it will change . Not what it was cut at the wear . Larry

 

[Jay Christopherson]

Not or do I care . After it is shot 100 time it will change . Not what it was cut at the wear . Larry

Care I shot . 100 wear cut but back. Yes!

 

[DaveTooley]

Same design/spec/name or was the same reamer used on different barrels?.

 

[Alex Wheeler]

I have seen the same reamer end up with different seating depths if used in different brand barrels. Different bore and groove diameters can effect where the bullets ogive touches.