Once fired brass sizing

[philip.cloete]

Good day all.

Hope someone can help me.

I started reloading recently for my howa .308 bolt action. After the first firing on the new brass I found that the Lapua brass is now shorter than the new cases. I measured all cases and found that they differ as much as 5 thousands of an inch (measuring with neck comparator).

From here I took the difference of the COL to the measured readings from the neck comparator to get a rough idea of what the case neck lengths is, this also was found to be out by a couple of thous.

My question is what do I do from here as I was planning to only neck size the cases but this will give allot of inconsistent rounds.

The next option that I was thinking of is to bump the cases back to get them consistent and then trim case necks after that so all cases is consistent but I was also not planning to trim at this stage.

Can someone please guide me in the right direction to get the most consistent cases without running into problems with the next reloading cycle.

Thanks in advance

 

[Dthomas3523]

Use this method from video to figure out your shoulder bump. Full length size every time and you’ll never have any problems.

I trim/chamfer/deburr every firing as I have a fast machine. If you don’t, you can just trim when it’s needed.

 

[Ryridesmotox]

Did you use the same powder charge for all the cases on the first firing? Or were you testing loads with them also?

I notice on my howa the ejector is a pain to get out. So I just basically size until I can close on a case with the same amount of force as it takes with an empty chamber. For my howa that like 1.570 base to datum with my sinclair bushing in my hornady comparator body. Youre mileage may vary

 

[918v]

Removal of the ejector is unnecessary

 

[Rocketmandb]

You are over thinking this a bit.

Some notes:

- After firing, your chamber will set the size of the brass from the neck down, and they should all be very close to each other.
- The overall case length may vary after the first, and to a lesser extent subsequent firings. This is why you trim the neck.
- You mention only neck sizing. Most people here will recommend full-length resizing and bumping back the shoulders .002"

So what to do...

- Measure the shoulder of a few pieces and set up a full-length resizing die to bump it back .002"
- Resize the brass.
- Measure overall length of a bunch of your brass, and decide what you want yours to be. I usually pick a length that is on the shorter end of the bunch, but still within spec.
- Trim brass to that length.
- Prime and load!