sizing questions

[remmag]

Hey guys
I am loading 223 cases and have a question or 2 regarding sizing.
I loaded a batch of cases and ran them through a bolt action .
I have measured the headspace measurement on the cases with hornady headspace Guage
At 1.456
I am measuring my prepped cases x checked with a Wilson case gauge and they measure at 1.458
.002longer than the fired cases
Is there some discrepancy in the measurement of the fired cases
from the actual chamber
Also if I am reading the saami spec right actual head space should be 1.463 to 1.473
Per my Wilson case Guage I am good but the measurement I get with the hornady Guage shows outside of written spec
Could the difference I am seeing be where the bushing tmrasures on the shoulder
Thank you for any clarification

 

[ArchAngelCD]

Cases don't have headspace.

You are way over thinking this, size the cases, check the function in your rifle, load them and shoot them. Sorry that probably isn't what you wanted to hear but it is the truth.

 

[remmag]

That makes total sense
So far a k have cycled fine

Just trying to learn all I can

Thank you

 

[rg1]

I just measured some sized loaded cases with my Hornady A-330 bushing of the Hornady Headspace gauge. I get 1.458" with my Hornady tool and measuring with my RCBS Precision Mic I get zero. These cases were fired in a AR-15 and after firing they measure about .004" longer than 1.458". Possibly your bolt rifle with a shorter chamber than an AR they are not expanding forward as much, plus springback, plus a light to medium load doesn't expand the shoulder as much. It's possible the swelling of the case would actually shorten the shoulder? My one bolt rifle in .223 has only 2 thousandths headspace from my sizing back to zero. Check several fired cases and get an average. Like mentioned, zero is around + or minus a thousandth from 1.458" and this is from measuring a few factory rounds and comparing to my RCBS Precision Mic. Correct that a case doesn't have headspace only the rifle but the distance from a chambered round with the head of the case against the bolt face and the space between the case shoulder and the rifle shoulder is what I call headspace.

 

[Reloadron]

Cases don't have headspace.

You are way over thinking this, size the cases, check the function in your rifle, load them and shoot them. Sorry that probably isn't what you wanted to hear but it is the truth.

That pretty much covers it. While the Hornady gauge kit is OK they are not always very accurate. Case in point, I have a set of 223 headspace gauges that I know to be true.

Go = 1.464"
"No/Go = 1.467"
Field = 1.470"

Measuring using the Hornady gauge I get 1.462", 1.465" and 1.468" respectively. Something is lying and it isn't my headspace gauges. Just set your dies up per manufacturer's instructions and check the first few resized cases using the Wilson Case Gauge which is a more Go or NoGo gauge and run with it. If they look good in the Wilson gauge then they are good. Do not over think this as mentioned. The Hornady gauge has its place and this isn't the place.

Ron

 

[Walkalong]

As long as the cases fit your chamber, and you don't push the shoulder back too far, you'll be fine.

http://www.thehighroad.org/showthread.php?t=768756

http://www.thehighroad.org/showthread.php?t=734058

 

[Reloadron]

Here is another read on the subject:

http://www.thehighroad.org/showthread.php?t=759018&highlight=Headspace+Gauges

Ron

 

[243winxb]

223/5.56 - Comparators

Is there some discrepancy in the measurement of the fired cases
from the actual chamber

Yes. 1. The head to datum measurement may get shorter as the case body expands outward. 2. The firing pin strike (223 Axis) may set the shoulder back .006"

 

[steve4102]

The Hornady Headspace gauge is not precise enough to compare to SAAMI specs. Forget SAAMI as it has no place on your bench when adjusting your dies.

If your "fired then sized", cases measure longer than your "fired not sized" cases, then your FL sizing die is not set up correctly. If the die is not set up correctly the case can grow from head to Datum line.

 

[Walkalong]

Yep, as the case body enters the sizer and is squeezed in, the shoulder moves forward at first. Only when it hits the shoulder machined into the sizer does it start to move backwards. If the sizer is not down far enough, you can actually end with with cases where the shoulder is too far forward.

 

[remmag]

Great info and thank you let me ask this
I have tried it thjs way,

If I take a case That Is sized l correct per the Wilson case Guage , then measure with the hornady head space Guage the measurement is at 1.457
I have some cases that are sized too far per the Wilson case guage, the cases that are sized too far measure at 1.452
On the hornady guage,pushed back .005 too far

Am I safe to load and shoot these cases or should I discard
They are mixed brass


Thank you

 

[243winxb]

If 1.457" is your maximum chamber head to datum, its safe to go .006" under. Its common for dies to do this when the shell holder is contacting the bottom of the die. Pushing the shoulder back more than .010" may cause brass to stretch too much, resulting in case seperation. At .014" separation will happen, but may take more than one loading.

 

[243winxb]

FL sizing for a Bolt action

When sizing for a bolt action, look for a crush fit when closing the bolt. This will tell you the head to datum is at maximum chamber. Then just bump the shouder back .002" or .003"

 

[remmag]

243
Thanks for the response
I will shoot up what brass I have sized and next time I will know

Thank you

 

[witchhunter]

When adjusting a die for a bolt action, size it just so the bolt will close easily. This may take a couple of tries to get it right, but it will be worth it in case life, and you will not create any unneeded headspace. If you size to much, you will create headspace and your brass will stretch when fired, causing a weak point in the brass just in front of the case head or belt. You could have a case head separation there. (a horizontal crack)