Brass growth and die settings?

[TrxR]

Whats the average growth on once fired 308 Lapua brass? Im guessing it depends on the chamber?

I was checking my brass and my once fired brass according to my hornady comparitor grew between .004 and .005 and .002 at the web. Is this about right?

Now would it be a good or bad idea to use these figures to set my body die to for my after my next firings? Or should i just neck size this time and see what they are at next time?

From my measurements the brass started at 1.619 and grew to 1.623 or 1.624. At the web they started at .468 and grew to .470 .

This may be a dumb question but i tend to overthink things.

Thanks

 

[emerson]

I don’t have much Lapua brass, but my other brass grows longer overall during the full length sizing process. Not much growth from firing though. I only f/l size when it gets tight to chamber the brass.

 

[supernova]

Do this: take your fired measurement and add .001". Adjust your die to that. See if it chambers. If it doesn't, bump it .0005" until it chambers freely with no resistance. Use that number.

 

[1-trident-1]

I would neck size only, and see if the bolt closes easily on the empty case. if it closes with resistance, bump 3 thou, try again. I think your chamber is closer to 30 , each rifle is different. a head space gauge is good to have.

 

[bigedp51]

If you have a fat chamber and a skinny full length die it will make the brass "grow" more when reduced in diameter.

Example a small base die will make the case grow more than a standard die because it reduces the body diameter more.

Meaning the brass growth depends on how well the die matches your chamber.

And .002 expansion just above the extractor groove can mean you are loading too hot, and also stretching the primer pockets.

Read the link below.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads

The shell holders below are like placing feeler gauges from .002 to .010 between the die and shell holder for "LESS" shoulder bump. Meaning you never have to touch or adjust the the die to control the amount of shoulder bump. And all you do is change the shell holder to adjust the amount of shoulder bump.

Competition Shellholder Sets
https://www.redding-reloading.com/online-catalog/35-competition-shellholder-sets

Makes every die a custom die!
Now you can control headspace. The new Redding Competition Shellholders are packaged in five piece sets in .002” increments (+.002”, +.004”. +.006”, +.008” and +.010”). Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will decrease case-to-chamber headspace. You can now easily adjust the shoulder bump to customize cases to your specific chamber.

 

[TrxR]

bigedp51: If I can get the calipers on that thin line just above the taper the cases measure the same but just above the line is where the growth is.