223 headspace

[Doctor]

i have a case length gauge that i am going to figure out which brass needs trimming

is this what they mean to use for headspacing?

[Dirty Rod]

A case gauge will tell you if you are within spec. Dillon gauges, for instance, show you min and max for that caliber. If your cases go in the gauge and sit between min and max then your cartridge should chamber without excessive or too little headspace. That assumes, of course, that your chamber is within spec.

Edited November 4, 2014 by Dirty Rod

[RDA]

i have a case length gauge that i am going to figure out which brass needs trimming

is this what they mean to use for headspacing?

No, headspace is the distance between the face of the bolt and a specific point in the chamber:

http://www.odcmp.com/Sales/askarmorerheadspace.htm

http://www.forsterproducts.com/store.asp?pid=24834

[Youngeyes]

When you neck resize a case you are only getting it ready to accept a new bullet. When you full length resize you are resetting the brass to fit the gun's headspace. Make sure you resize before you trim the case.

[tcoz]

i have a case length gauge that i am going to figure out which brass needs trimming

Rather than using a case gauge to determine which brass needs trimming, I just set my calipers a couple thousandths under the max length then run each case through. If it passes through, I don't trim. The advantage to this is that you can set it to whatever length you want rather than depending on the fixed length of the case gauge.

[dauntedfuture]

You are talking about two different things: head space which is the distance from the front of the bolt to the "front" of the chamber, or on brass its from the base to the shoulder of the case. We size brass so that it will fit back in the chamber or push the shoulder back to where it should be. OAL case length is the distance from the case head to the case mouth. If a case is way too long it will go into the throat, crimp the bullet and not release it and jack the pressure up.

You CAN use SOME chamber gauges to check headspace and OAL length. Most are cut so that if the neck of the brass sticks out, it needs trimmed provided it drops into the gauge properly. It think you will find that its almost easier to just try trimming all the brass. You can usually get away with trimming just once after the initial firing if things are set up properly and your not shooting an M1A. You SHOULD check OAL case length to make sure but most of the time you will be OK.

I have a Girud trimmer so its faster for me to trim all the brass each time.

[RiggerJJ]

all my fired rifle brass for 3 gun goes thru a processing head with sizer and Dillon trimmer. I don't waste time measuring it before processing, just run it. then it gets tumbled to remove lube, and after that loaded with a different head.

for precision rifle brass I basically do the same thing but on a single stage; neck sized, trimmed with a lee quick trim die that trims chamfers and deburs, then loaded...

the headspace question has been answered by others above...

jj

Edited November 12, 2014 by RiggerJJ

[Raydee38]

JJ when you neck size only are you using just a neck sizing die? I have about 500 fire formed cases that I was thinking about just neck sizing for my bolt gun but I wasn't sure if it should have the shoulder bumped a thousandth or so just to be safe.

[RiggerJJ]

The only way to answer that question is to measure the chamber headspace and compare it to the brass. Bumping it to .001 spacing will work I think. I usually just shoot em, and neck size em with a neck die. Most will rechamber, from what I understand after 3-4 firings they will probably need a shoulder bump. I've just gotten started into the world of precision loading this year, so I am not the brightest bulb in the shed...but I read a lot and ask a lot of questions.

jj

[dauntedfuture]

save yourself some time and effort and FL size everything. You can use one die for multiple rifles, just set it so the brass will be sized enough for the smallest chamber. Keep your brass separate for each rifle if possible.

If you shoot, or fire, brass in a rifle it has been fired. If you are fire-forming brass you are shooting brass in the chamber that's not exactly firmed correctly; for example to make a .223 AI, you shoot a .223 in a .223 AI chamber: you have now fire-firmed .223 to .223AI and can now load the .223AI with .223AI data as you have another 3g case capacity or so. When you size .22-250 brass in a 6x or 6xc die you have now un-fire-formed brass that's sized for a 6x or 6xc, after its been fired once, its been fire formed. You can also fire form cases with some pistol powder and cream of wheat if you want to form the brass without burning out the barrel.

I am also in the "trim everything every time" reloading camp.