Does brass matter?

[Marbles]

Op are you using the starline 223 or the 556 brass.

556.

Have tried PPU brass? I have a bunch, once fired. If you would like to try some, I can send you some. PM me. It’s not Lapua but not bad.

I have not. Thank you for the offer, at the moment, for simplicity, I'm going to shoot out the 500 starline cases I have and dedicate this other headstamps to hunting and field shooting as I will loose them.

At the moment most of my shooting is positional work, which has decreased my playing around with loads as assessing accuracy meaningfully from offhand and seated is hard, as is using a chronograph.

 

[MJW]

Interestingly, the Starline had the best SD this round.

Starline
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Winchester
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FC
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Sig
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I'll have to get the data in excel.

That looks pretty good.

 

[MJW]

Already pulled the Winchester brass for hunting rounds as it is annoying to reload (some of the cases try to pop out of the hand primer and I have to hold them in by hand). The FC brass has tight primer pockets despite having the crimp reamed, and I'm tired of messing with it too. So this will be the last data point.

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This is a prefect example of the mystery of ES. Not my theory but another young man, Ian Klemm, vortex pod cast? I have experienced this myself and fellow shooting buddies. Loads that have ES’s that are not what you would think is a good load but groups better than a load with a tighter ES at longer distance. What?? Well, as the theory goes it has more to do with when the bullet leaves the barrel, barrel dwell time, during the whip or harmonic cycle. He calls it positive compensation. Here is a clip, check it out.

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In the three targets you listed i would shoot load #2, (target 2) at you max distance you intend to use the round and see what the dispersion looks like. One thing to keep in mind is that working with small cartridges, it is tougher to control ES than it is with larger cartridges, simply due to the percent of powder. Target 3 is some what strange. Shots 1,2,3 and 4 are the ones to question. Is it shooter error or is on the edge of a scatter node? Granted we are looking at three different brass types but there is some correlation as it pertains to bullet exit, timing. So, lets say if you really wanted to use the Starline brass, maybe pull some powder to achieve the lower 2500 fps range and see what you get. The reason I mention this is look at the SIG target posted earlier above, tight water line and that lower 2500fps range. That ES is nothing to write home about for sure but that doesn’t mean you can’t achieve A lower ES with the other brass and a solid grouping. That’s how i would work the load moving forward.

Bottom line, ES is important, and you should try and control it as much as you can, but don’t beat your self up over it. Work with in your means and be realistic. Set your MOA goal throughout the range you intend to use the cartridge and work to achieve that goal. If it shoots 1 MOA at 100 yards and 1/2 MOA a 400 then that is a win.

 

[Marbles]

I kept the 10 Starline 5.56 brass used for this thread and used the for load testing to speed up the number of loadings. Brass is being FL resized, and most loads were on the warmer side.

At the 9th firring, one case broke in half below the shoulder and several others had hairline cracking in the same spot. I have not been annealing. Primer pockets were still tight.

I've not ran any of the other headstamps to that number of loadings. The Winchester and FC brass are both annoying to prime. The Sig brass has been nice to work with, but given the lower velocity than the Starline, it is easier not to have it in the mix.