Zero fired brass gives erratic SD-ES

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MartyK2500

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For some reason I can never get my virgin brass to group as tight as once fired, and it shows on Labradar as both SD and ES are double digit.
Once my brass is 1F, I get back to single digit SD - ES.

I wonder what could be improved in my process to cure this problem.
I set back shoulders and fully resize brass body every firing, so I don't think it has to do with the brass being fireformed to chamber.

Also when brass is virgin, I give it one pass under the Sinclair expanding mandrel, bullet seating feels very consistent.
Don't know what's up here to be honest.

In 308 I used to say eff it and use virgin brass for sighters or foulers,
Now in 6.5 I don't feel like wasting barrel life/brass life anymore.
 
I don't believe there is anything to be done to the brass other than to fire form it to the chamber. I believe that most shooters that do load dev do so with fire formed brass. I know I do as the numbers with the virgin brass are never constant. When brass is resized it is never sized back to virgin brass #'s unless small base dies are being used. JMO
 
How’s the bullet and neck runout?
I’m going through the same thing right now with 200 virgin alpha brass.
The necks where to tight so I expanded them. I think the expander introduced a bunch of runout.
Putting them back through a standard type full length die was the only thing that seemed to straighten them out.
Just in the process of re trying them. The neck tension is still tighter then I would like but better then a bunch of runout I’m hopping.
Joe
 
MartyK2500 said:
For some reason I can never get my virgin brass to group as tight as once fired, and it shows on Labradar as both SD and ES are double digit.
Once my brass is 1F, I get back to single digit SD - ES.

I wonder what could be improved in my process to cure this problem.
I set back shoulders and fully resize brass body every firing, so I don't think it has to do with the brass being fireformed to chamber.

Also when brass is virgin, I give it one pass under the Sinclair expanding mandrel, bullet seating feels very consistent.
Don't know what's up here to be honest.

In 308 I used to say eff it and use virgin brass for sighters or foulers,
Now in 6.5 I don't feel like wasting barrel life/brass life anymore.
Click to expand...

It gets more fun... with some really hard brass, it might take a couple or 3 firings to really set the brass for peak LR accuracy.

COW forming can help but ultimately, you are going to run a typical charge to set the brass.

If you are doing positional practise, then use the new brass and form away while you practise. If you are using this for competition, don't worry, your 2nd barrel will show up before this barrel burns out... and then you will have excellent brass for those barrels.

Some suggest hydroforming can help... I can't be bothered... I need the practise and another 200 to 300 shots to learn the wind is money well spent.

besides, you should have 2k worth of match shooting using the 6.5X47L...

And you are also breaking in your barrel.... so you are accomplishing several tasks at the same time.

Jerry
 
ruffbird, I doubt Lapua brass needs flash hole deburring, never done it with my other batch of lapua brass and got extremely good results.

joehunt, after expanding only 2 casings, I noticed there was some force required to do so. And the expander does not support the casing on top of it. Checked my first 2 and yes I had induced runout.
For the rest, I slightly sprayed a Q tip with Hornady one shot, outdoors cause that stuff will kill you, and once expanded I rubbed the neck interiors with another Q tip to take the excess lube off.
Doing this has so far induced zero runout. Cannot comment for once fired as i'm still going through my zero fired brass.

Ganderite, I am presuming I have a 20 thou jump right now.
Since Hornady doesn't make a modified case for this caliber of mine, and didn't get around to make one yet, I used this you tube video method to determine lands.
It felt so accurate I didn't feel the need to test anything else, I may be wrong.
It's fun to finally use this technique, all my other rifles are savages, and when you remove parts from inside the bolt, the bolt head pin will not stay in place anymore, making this test impossible to do.
The Origin does have a floating bolt head, but the pin is still snugly in place with internal parts removed.

https://youtu.be/TWmIwPwLyyg


Jerry, I heard a local Fclass guy say he did very well in a match with 0F Lapua brass, I have been trying to get my 0F brass to have a meaningful use since then to no avail.
Since i have no proof of this i’ll do what I used to do with 308, use my 0F brass for barrel foulers after a clean, to try positional shooting etc...

Just youtubed hydroforming, looks like a pain in the rear i'd rather shoot less accurate rounds down range.

I didn't know a barrel had a break in period.
A factory savage I do the shoot 1 patch 1, shoot 2 patch 1, etc... method, for IBI I thought they we're ready right out the door.
I'm at round count 70 right now, this is the last target I shot yesterday at 200M, a 10 round group in the rain, but I was shooting from shelter.
I got more vertical at 200M here than my 308 has at 300M, but the labradar was there and showing high SD-ES also.
Currently at 36.5gn Varget using CCI 450 primer. Was the best load I could find for 0F brass after 3 outings testing loads.
2725FPS with 142SMK.

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