Home Forums Hunting & Shooting Ask The Gunwriters Case length variance question

I opened a new bag of Lapua 30-06 brass today to use for load development in a hunting rifle.

After full length sizing, 30 of the 50 are in the range 2.482-2.483”

12 range from 2.481-2.479

8 are longer than 2.483”

How much variance would you accept in case length? I figured I would trim the 8 down to 2.482” and keep the other twelve segregated.

But if that overall variance is negligible I’ll just load and shoot.

I'd be inclined to do just as you outlined.

I'd be inclined to simply load and shoot them. If you are crimping, there will be some variation in the crimp, but probably not enough to worry about. More meaningful (though not by a lot) is the variance after firing, before sizing. GD

Just shoot em. A few thousandths is not going to make a difference as long as they are not over max length.

I opened a bag of Lapua '06 cases yesterday. Guess you have to buy 100 to get the plastic case.

Pulled out 25 that didn't have dinged necks. Seated a bullet and measured 0.003" neck tension. I'm good to go - no f'ing around FL sizing them. I'm guessing they were closer in length before you went thru that unnecessary operation.

I plan on using a tapered punch before loading on those with dings and a boat tail bullet on the first loading.

I was really impressed with the way Peterson puts their 50 rd batches in a nice plastic case with foam padding on the top to keep things for rattling around.

Shoot them as is and trim the whole batch after the first firing/resize. They're all going to stretch on firing, no point in wasting time before that.

Yep. Sizing past an expander-ball will stretch them too. Shoot-size-trim and then go back to what you think is your best load and double check when everything has been run through your gear.

Exactly--though I do tend to measure the OAL of new brass just to make sure it isn't too long. Have been bitten by that occasionally...

I have found them occasionally to be long before the first loading, but since I have a Giraud, I figure why not hit 'em before the first load.

When all I had was an RCBS trimmer and loaded 20 rounds, 50 at most, I'd wait as long as I could. I hate trimming.

👍👍

Fire and then check. My prep always follows a first firing to get all sized to chamber dimensions.

For new brass I simply run an FL die high so the expander ball just hits and uniforms the dings, chamfer and deburr and fire pthem. I don't even bother to lube them, no need to if you are only using the expander and not going into the neck area of the die.
Cat

I run the expander all the way through the necks, to make sure inside diameter is consistent--which helps with initial accuracy testing. There's still no need to lube inside the necks, because new brass is pretty slick.