min case length for 223?

[par0thead151]

I like to trim my brass on the shorter side of the recommended range as my trimmer is inconsistent with different brands of brass. im not sure if it is the reloading press or the trimmer, but some cases are at 1.759 or above when others are 1.750-1740.
the trimmer is a giraud, so it is quality, not some cheap junker.
should i be concerned about the 1.740 length ones? i dont mind the longer ones as i measure each case before loading, so those get re trimmed to proper length anyways. its the shorter ones that worry me. i usually keep a consistency of 1.748-1.752 when i am set up, however there are a few that are outliers and are above or below that.

 

[rcmodel]

Any chance you are trimming them before you size them?

.019" variation is A Lot for any trimmer, especially a Giraud.

Cases "grow" when they are resized, and if you are trimming before sizing, you are just spinning your wheels!

As for the short cases, there is some thought that erosion of the chamber neck will be the eventual result.
How much and how long it would take is open to speculation as far as I know.


rcmodel

 

[par0thead151]

i tumble, resize, deprime, tumble, remove primer pocket crimp, and then trim.
resizing and deprime is done on a dillon 650 with dillon carbide dies.
all the cases fit in a case gauge, so im wondering if it is not a short stroke problem, as i am usualy very good about making sure it goes down all the way, heck im almost tempted to put a buzzer in for when the press reaches the bottom of the cycle for resizing just to ensure i get it all the way.

 

[John4me05]

Carbide rifle dies???? I thought only pistol had carbie.. Hmmm

 

[Ed_E]

I think, more importantly, the dimensions you should be monitoring carefully for your .223 rifle are the head spaces of the rifle and cartridge. On a cartridge it's measured from the case head to the shoulder datum line. On a rifle it is measured from the bolt face to the point in the chamber that corresponds with a case datum line. Then determine the bullet jump distance which will set the overall length required for the round.

For a very good discourse on this subject get a copy of Glen Zediker's book "Handloading for Competition." It will answer your question and much more.

 

[par0thead151]

i do check each case with a dillon case gauge before loading as well.
sitting in front of the tv on the sofa i usually have a bag of brass to check with a micrometer and case gauge.

 

[Bullet]

From GIRAUD -

Next, check your overall length of the
trimmed case with a caliper. I will set
the length fairly close, but it will really
depend on how you size your brass.
Since the case trimmer locates each
case by the case shoulder, if your
headspace dimensions on the resized
brass are not consistent, then the
case can't be trimmed to a uniform
dimension. I suggest the use of some
type of headspace measuring device
to monitor your resizing operation.

You might want to purchase one of these to check your cases -

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=477756&t=11082005


I use the RCBS Mic to set my sizing die and check my cases. I haven’t had my Giraud trimmer very long, but I gave up measuring my cases after about 25 because they were within .001 of each other using the same brand brass. Mine is set for 1.754 from Giraud, I didn’t have to adjust it at all. Are you lubing your cases for your carbide dies? I’d check your cases with the Mic first. If they are the same It’s probably using different brands of brass that makes a difference. Don’t mix different brands of brass and see what happens.

should i be concerned about the 1.740 length ones?

If they have enough neck tension to prevent bullet setback, I think they should be OK, but I'd try to determine why this is happening.



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