Large deviation when loading .223

owtlaw

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Minuteman
Feb 27, 2013
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I started using H4895 for .223 recently. I have a whole bunch of Wolf primed brass left over from a few years ago so I started doing some work up on that. I am using a 69 gr Match Burner and have used 23.8 gr 24.0 and 24.2 grn of powder. My OAL is 2.255" My velocity is coming in with 60 ish FPS deviation. My primers are starting to flatten. What am I doing wrong that I am getting these kind of velocity swings? Temp was at 57 degrees when I tested.
 
You said Wolf primed brass. Is it NEW brass or brass shot and processed and if so neck tension would be the first thing I would look at.

Mic you loaded rounds and and then mic your sized rounds and see how much the diff is.
 
223 is a notoriously difficult cartridge to get low standard deviation.

On Sunday, I was shooting 24.5 grains of varget in brand new Lapua brass measured to the resolution of the A&D FX 120 scale and my standard deviation over long stretches was 20 ft./s. that’s kind of to be expected with 223 so I don’t sweat it. it is a 75 ELD load, and it still bangs the shit out of the thousand yard gong

I imagine using Wolf brass would only make matters worse

I also suspect that now that we are all using the Garmin to capture every shot over long stretches that we are going to find that our previous notions of our standard deviations were wishful thinking because we discarded a lot of data and cherry picked the good stretches of five or 10 rounds
 
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You can try bumping up the load a little and see what happens, but I am also of the opinion that 223 is notoriously difficult to get quiet velocity stats.
It is worth a quick check with either a different brand of brass, primer, or even both. That would tell you if the Wolf Primed Brass was a contributor or of this is just the way your bullet and powder play together with this rig.
 
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223 is a notoriously difficult cartridge to get low standard deviation.

On Sunday, I was shooting 24.5 grains of var in brand new Lapua brass measured to the resolution of the A&D FX 120 scale iand my standard deviation over long stretches was 20 ft./s. that’s kind of to be expected with 223 so I don’t sweat it. it is a 75 ELD load, and it still bangs the shit out of the thousand yard gong

I imagine using Wolf brass would only make matters worse

I also suspect that now that we are all using the Garmin to capture every shot over long stretches that we are going to find that our previous notions of our standard deviations were wishful thinking because we discarded a lot of data and cherry picked the good stretches of five or 10 rounds
Agreed. Even after shooting groups I leave the garmin on while I'm shooting steel. More data never hurts. What's considered a good SD and ES for 223? I'm newer to this aspect of it. My last string of 30 shots was an SD of 11 and ES of 58. Pretty much all my SD's have been under 20 and the ES has been 40-70. ES seems hard to control on the small caliber.
 
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My sample sizes are much smaller, but I'll test 5-6 groups of 5 shots at a time. I've found with the .223 the more case fill correlates to lower ES and SD better than my other cartridges. You'll certainly run into pressure first with H4895 though before you fill a case.

Virgin brass can definitely make a difference too, but the higher quality stuff isn't as much of a factor as the general stuff. I'd at least run the cases through a mandrel or over an expander ball for interference uniformity, regardless of who made the brass.
 
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Depends on the rifle, but I have loaded for a couple 223s that I was really happy if I got a sd in the teens.
My Criterion barrel with a 223 Match chamber is an exception as I can get (or near) single digits with it.
But as others said, a 223 is a challenge for low sds.