PEIRob & Al Nyus's Method's for determining freebore...

too much

Vani B watch your head space 5thou is to much
regards Jim.
 
Just drill and tap the primer pocket 8-32 and slit the case neck of a resized case. Then thread a cleaning rod section into the primer pocket and start the smoked bullet into the case neck and push it into the chamber. Jon
 
j mckinnie said:
Vani B watch your head space 5thou is to much
regards Jim.
Click to expand...

Oh geees. Here we go again. :D

Ok.....so then if there is really a 5,000th's space that I believe I'm measuring, then the the smith might have messed up?



However....I sure don't want to go accusing the smith now of doing something wrong. -Been there already accusing the smith and/or the reamer maker of committing horrible "excessive freebore" offenses against mankind. My measurements can be off again...as 5,000th's of an inch is like splitting hairs.....and I am still in the process of trying to learn to differentiate between my ass and my elbow with this stuff.

I can tell you that when I feed the empty Lapua case into the chamber with a stripped bolt , and lock it into the chamber, there is no felt camming tension. When the ejector is left in the bolt, then it closes on the case with a more normal feel of tension......which undoubtadly is probably the spring tension of the ejector I'm feeling. I realize too it may not be practical for a smith to desire to fit every new and unfired case to a bolt face tightly. I imagine if a new Winchester case was made to fit snug....then perhaps the bolt wouldn't even close on the larger and thicker walled Lapua case?...or not close easilly.

I suppose the worse thing that can happen if the headspace is off a few thousandths, is my Lapua case might reload 9 times instead of 17 times? :D

I'm listening.

EDIT:
YES BRYCE, I'm happy now ....and no headspace question involving 5,000th's of an inch (possibly) or anything else is going to steel my stinkin joy! :) :D
 
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VaniB said:
Ok.....so then if there is really a 5,000th's space that I believe I'm measuring, then the the smith might have messed up? ..................................

YES BRYCE, I'm happy now ....and no headspace question involving 5,000th's of an inch (possibly) or anything else is going to steel my stinkin joy! :) :D
Click to expand...

VanB,
Don't feel bad, I would hate to admit the number of years that I reloaded and shot informally without understanding what it takes to insure that a resized case fits the chamber........... This is the reason benchrest shooter obsess about the quality of the brass, use custom dies, etc. If your resized brass has .005" headspace in your chamber,I wouldn't blame anyone. You can fit the brass to the chamber or have someone fit the chamber to the brass, either way takes some measuring and thought just like you learning the bullet to land distance. Good luck, winter is the best time to get it all worked out!
 
Some real good info here for all to ponder.

We substitute the candle & smoking the bullet with a black or blue white board marker pen (or any felt tip pen).

Just seat the bullet in the case, colour in the bullet head with the pen so it is all black and use whichever way you feel confortable with in determining the bullet seating depth.

I bought a rifle from Darrell Holland which came with a bullet seating gauge~real neat.

He made it from the waste section of the barrel, it is machined in such a way that you can hold 80% of the case in your hand and the rest goes in the gauge. All you do is seat a bullet long and keep reducing the seating depth till the shoulder of the case hits the shoulder of the gauge.
This gives me the starting point, the final adjustments are made by tweeking the rounds, and shooting holes in paper.

Will post a picture if I can work out how?

My kids love colouring in the "DUMMY ROUND"

And you get to keep your candles for power cuts!

PS I am a hunter and not a benchrester, but I do expect benchrest accuracy from my hunting rifles where possible.
 
BJS6 said:
..... The case needs to be full length resized correctly for you to be able to insert it fully up to the shoulder, even once fired is to tight to get the case right in their without decent force. If the case is a free fit and does hit the shoulder your readings should vary from using the bolt by the amount of shoulder bump you are doing. If you are bumping the shoulder back a bit far during full length sizing your estimation of bullet seating contact point will also be out by the same amount.

Yes there are a lot if Stoney Point tools giving inaccurate readings, been there and done that.

Bryce
Click to expand...




I think Bryce has it covered best in that quote. He has covered two topics that are evidently being overlooked in some of the continuing posts on this thread.

Point 1:
It is probably to be expected that when I am starting with NEW AND UNFIRED BRASS, it could likely start off with being a few thousandths off the chamber's shoulder walls. But, this excess headspace will certainly be eliminated after the first firing.

Will a new and unfired Lapua case being subjected to a headspace gap of 5,000ths cause severe case streching ands premature case life? jmckinnie seems to think so........but, unless some of you other guys chime in and agree, I doubt it, and will not worry about it. 5,000th's of an inch is not even the thickness of a business card, and would seem to be nominal and acceptable.....and what maleable brass should be expected to adjust to easilly without sacrificing its working life span. Bryce's quote suggests that continued improper resizing and "bumping" of the fired case should be more of a hazard to the cases lifespan.

Point2:
If a Stoney Point chamber gage isn't the best tool, then how well do you think these home made dummy cartridges with sliding bullets will work? I can tell you that I got false readings using these home made slide rule devices. Maybe it's just this reamer chamber that I'm working with, but the only time I finally got true freebore readings was when I kept feeding a dummy cartridge back and forth each time into the chamber, WITH THE BULLET FIRMLY GRIPPED ONTO THE NECK. Maybe I'm using the wrong magic marker too, because I couldn't read the bullet freebore with a magic marked bullet when the readings became so small and precise (within a few thousandths), that the lands barely touched the bullet. Only contact sensitive black soot shows the slightest contacting of the lands. AND SOME OF THOSE FINER INSPECTIONS REQUIRED I USE A 5X EYE LOOP, ON TOP OF MY READING GLASSES!

I'm not knocking what you guys say works for you, just explaining that some of it did not work for ME.


Then again maybe jmckinnie summed it all up best with this comment:
Your making a big deal out of finding a close reference point .In the end your seating depth is trial & error.the target tells you the correct place to seat the bullits.Have fun & good shootin Jim

:):)
 
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