Factory second 88gr variation

[hi-wayman]

Earlier this year Midway was selling these for cheap. I stocked up planning to use them for practice ammo.

I have only gotten my SD's to the low teens using new Norma brass and N140. I'm using the same methods that yield low single digit SD's in my 6.5.

I figured seconds, right?

I got curious because these don't LOOK seconds and weighed a batch.

WT - ## - percentage
87.6 - 02 - 01.5
87.7 - 01 - 00.7
87.8 - 15 - 11.0
87.9 - 46 - 33.8
88.0 - 36 - 26.5
88.1 - 23 - 16.9
88.2 - 08 - 05.9
88.3 - 02 - 01.5
88.4 - 02 - 01.5

Ok, right? But I also found one that weighed 77.2gr. it appears identical.

So now do I go through and weigh/sort all 3000 pieces? It should give me better ammo, but that's a lot of sorting.

[mRad]

What is your goal here? Numbers for the sake of numbers? Performance in target? Without weight-sorting, how are they willing to perform? What sort of weight variance are the factory firsts?

Weight sorting bullets doesn’t really matter all that much in my experience unless you’re trying to cull out mixed bullets I have seen factory second lots have a bullet or two from other SKUs mixed in.

What does tend to matter more is bullet length. Length has more influence on the BC. BC variation tends to influence downrange vertical.

I’d just to a quick weight check before dropping them into the case to be seated to catch anything crazy.

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[Bimmer]

Are these .224"? What are you loading them for? (These won't fit in an AR's mag, will they?)

If just "practice ammo," then just load them.

If it were me, and I wanted accuracy, then I would sort out the outliers.

How big was your initial sample? How long did it take you?

[hi-wayman]

They are 224 and loaded too long for AR mags. They are meant for a long range 223 where SD matters. If I threw out a "velocity flyer" on my ten shot groups they would be 6-7 SD. I'll have one round off the avg velocity more than triple the rest. Good groups at 100 and 200.

The weighing was because I couldn't determine any other reason for being seconds. Visually perfect and identical lengths and bearing surfaces. And its been bugging me what the "seconds" standard was. :)

Sample started at partial bag and the numbers made me more curious so I opened another 100 for a total of 136.

The deviation of the "bell curve" maxes at less than 1/2 of 1 percent. I'd probably be fine with that.

The oddball that was light 10 grains, heh. Thats the rub.

I know I have to sort these now. Probably occasional wrong SKU like mRad suggested. I was just thinking of the tedium of sorting 3000. There may have been some single malt that helped my to share my observations . :rolleyes:

My electronic scale is integral with my powder tricker, not ideal for weighing on the fly as I'm loading. Though if I'm weighing them all, it is tempting to cherry pick the best out. 88.0 +/_ 0.1gr accounts for 77 percent.

[Bimmer]

The oddball that was light 10 grains, heh. Thats the rub.

If you're just looking to eliminate that kind of freakish outlier, then use a beam/balance scale.

Set the scale at 88gr, or whatever, and you'll instantly know whether a bullet is about right or not.

Or, set it at 440gr or 880gr, and weigh five or ten at once... If one is 10gr off, then you'll know it.

[Pappabear]

Man, that is a LOT of sorting. I would just load and let them rip.

PB

[Bimmer]

They are meant for a long range 223 where SD matters...

The deviation of the "bell curve" maxes at less than 1/2 of 1 percent. I'd probably be fine with that.

I'm not a stats guy (but I drink beer with them). It looks to me like you've got 5% that are lighter than 87.7 or heavier than 88.3, and you've got 3% (two each) that are 87.6 or 88.4, and that's a 1% difference in weight.

So, I don't know if that matters or not.

Spitballing: Before I weight them all, I would load 5 each of the 87.6/87.7 and the 88.3/88.4, shoot 'em over the chrono, and see where they impact at distance.

If there's no difference, then just hope that you don't find another 77 in the batch. (That one must be solid copper, right?)

If there's a difference, then start thinking about a weighing/sorting protocol...



Man, that is a LOT of sorting...

If he's just trying to sort out the 77s, then he could weigh 10 or even 20 at once...

[hi-wayman]

I can ignore the differences, except the 77. I view the high/low spread as acceptable for their use. It's just a 1/2 percentage point from the target of 88.

Its tempting to ignore the almost certainty that there are more 77's. Except my OCD starts kicking in.

I'll just have to go binary and figure on my scale max capacity. Compare 8/8, 4/4, 2/2... of course that assumes a light one isn't in each pile! whoops, there's the OCD again.

Takes for your input. I really can't complain about these bullets, I just like perfection. Shoot the ladder tests (10 @ each weight) showed SDs from 10.2 to 15.3. Not single digit, but better than any factory ammo i've shot in while.

[mRad]

At the end of the day, what’s the worst that happens? You miss because of a 77 gr having different dope?

I can live with an obvious flyer. You’ll know if it was shooter induced.

If OCD is that much, sell them and buy firsts but as you said, they are for practice. My time is worth more than the cost difference.


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[markm]

We shot a bunch of 88gr 2nds. If you're not competing and you get a odd weight/flyer, who cares? Send another one. It'll give you an excuse if you miss too! :cool:

[MegademiC]

How much less powder are you using than a 77gr load and how far are you shooting?

That weight difference might not even cause a miss.

[markm]

How much less powder are you using than a 77gr load and how far are you shooting?

That weight difference might not even cause a miss.

I know this question is for hi-wayman, but for our load, there's actually more powder than a 77 due to loading them longer. (2.50") And the velocity is about the same as a 77 at 2745 fps.

Based on our experience with the 88, I'd guess that the bigger weight variances might become an issue at 750 and beyond. At 1300, even the factory first bullets will get as squirelly as a 6.5cm when the weather/wind is anything less than ideal.