Valkyrie brass: Federal vs Starline

[Subwrx300]

Hey guys, looking for help on brass size for Valkyrie. Have a thread in Reloading that hasn't been answered in a week or two so I thought I post a link here to see you can test.

https://www.snipershide.com/shooting/threads/224v-federal-brass-too-short.6892705/

In my rifle, virgin federal brass grows a ton from shoulder forward. A comparator against virgin vs once fired shows .012 growth. If this is common to more people, it may be contributing to some of the difficulty in finding accurate loads. Once fired brass, bumped back .001-002 is putting up .4-.5 moa groups whereas virgin is staying around .6-.9 with bad SD and poor gas seal (very dirty coming out of chamber).

Anyone able to test their virgin Federal and/or Starline length halfway up shoulder before and after firing? Im using .330 comparator insert in Hornady Headspace gauge.

 

[MontanaMan]

The brass min HS dimension is 1.251" & the max chamber HS dimension is 1.265, so worst case scenario, brass at min & chamber at max could show a .014" change.................if all is in spec at extremes. Could get worse if either brass or chamber is out of spec in the wrong direction.

Likely you have some brass near min or maybe even below & likely a chamber in the long side.

I have seen brass in other cartridges below spec & have sent it back to mfg. & had it replaced, FWIW.

MM

 

[redneckbmxer24]

What you’re seeing isn’t uncommon, sounds like your chamber is just more towards max headspace. Just don’t size your brass all the way back minimum every time or you may get separation.

The increased SD you’re seeing on the virgin is mostly likely from the lengths varying and not the fact it’s growing as much as it is. Consistency is key. Essentially the difference is changing the volume more or less. There’s two ways to solve this. 1. Find the shortest length of the batch and size them all back to that so they’re all growing the same. 2. Measure and sort the brass by length to group it together. I’ve done this a few times now on batches when it varies by more than .002” and it has worked very well and doesn’t work your brass more like sizing.

The accuracy loss you’re seeing with the virgin brass is most likely from run out. New brass is never as straight as brass fired in a straight chamber and then resized with good dies on a good press. The lower the brass quality, the higher the runout tends to be.

Accuracy an ES/SD is always going to be better on fireformed brass, it’s just the way it is.

 

[Subwrx300]

What you’re seeing isn’t uncommon, sounds like your chamber is just more towards max headspace. Just don’t size your brass all the way back minimum every time or you may get separation.

The increased SD you’re seeing on the virgin is mostly likely from the lengths varying and not the fact it’s growing as much as it is. Consistency is key. Essentially the difference is changing the volume more or less. There’s two ways to solve this. 1. Find the shortest length of the batch and size them all back to that so they’re all growing the same. 2. Measure and sort the brass by length to group it together. I’ve done this a few times now on batches when it varies by more than .002” and it has worked very well and doesn’t work your brass more like sizing.

The accuracy loss you’re seeing with the virgin brass is most likely from run out. New brass is never as straight as brass fired in a straight chamber and then resized with good dies on a good press. The lower the brass quality, the higher the runout tends to be.

Accuracy an ES/SD is always going to be better on fireformed brass, it’s just the way it is.

Ive reloaded a lot over the last 10 years but have not had any cartridges grow this much from Virgin to once fired. I thought it could be related to my chamber but it's in the exact middle of spec. Have really only used Lapua, Hornady and Starline where it mattered for precision, so in my small rifles, I never felt the need to check new brass, until now. This is the first "early adopter" cartridge I've played with so I didn't have any reason to expect such large growth. It's never happened in the past, but those were 223 Wylde, 6.5 Creed, 308 Win and 243 etc. Good stuff and great post!

I do run all new brass through a resizer but since these are sized so much already, all it really does is clean up the neck, which doesn't necessarily make it concentric.