First time virgin brass prep

I would start load development right from the start . It's Starline and it's an AR, brass is going to get beat up every firing and you will likely see very little change after initial firing .

Did you anneal just for practice ? Bronze brush in the necks of virgin brass ?

You can use a vibratory for your last stage but not a tumbler for cleaning. The tumbler will dent the case necks you spent all that time with.


I only do load development after 100 rounds anyways (no dev on new barrels) so I use once fired brass

Kangbeef said:

Ok first round of prepping virgin brass. This may be over kill for AR loads but its practice for new project soon.
Starline 223 rem.
1. Annealed brass(diy annealer along with templac 750 degree F
2. Ran through just the expander ball on forster die lubed inside of neck
3. Debur flash hole
4. Ran .22 cal bronze in drill press to clean necks
5. Chamfer and debur
6. Dry tumble to clean lube and debris off

Ok so my one question is virgin brass and new 20" WOA barrel. Do i carry on with load development while fire forming at the same time or load the brass on the low side then resize for the load development. Just curious on how my work turned out and will listen to any advice.

Click to expand...

The main issue I have with virgin brass is that the headspace tends to be short and so they need to be blown out to fit properly (this is on of the reasons many reloaders will fire from their cases before load development). Typically, a new barrel takes 100 to 200 rounds through it to settle down . . . meaning, velocity will speed up as the barrel smooths out. But, I do like to looks at preliminary data during this "break in" period as it does help with the load development.

Running an expander ball or expander mandrel through the necks of virgin brass is a good thing to be sure any dents are taken care of. Also, chamfering and deburring can be an important step for virgin brass as very often, depending on which brand, and with Starling brass the case mouths have only been trimmed square leaving substantial burrs. Because it's just a one time operation, I'll deburr the flash holes too.

I think the only thing you didn't need to do is to anneal the virgin brass as the manufacturer does that and to redo it just isn't likely to change anything.

Honestly, all I do with new virgin Starline brass for my gas gun is chamfer / deburr and load, usually do load development after one firing.