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Old December 14, 2018, 10:34 PM   #26
Unclenick
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Rebs,

Hounddawg is right. If your groups are that size you have more dominant group spread influences than case irregularity and it will be close to impossible to discern any observable difference except perhaps at very long range. If you are using spherical powders, I have been able to measure improved ignition consistency from deburring flash holes in cases that have them (some of the more expensive brands, like Lapua, Norma do not). I have not observed the same effect on stick powders, but it's something I do for long range loads regardless of the powders used.

The reason it is hard to tell is statistical. If you introduce two sources of error, each of which will open a bughole group to 1 moa by itself, most folks assume that means introducing both sources of error at once will open the group 2 moa. It does not. It only opens the group by 1.414 moa (the √2 moa). This is because, when you put two error sources together they only add to one another a small portion of the time. Just as often they subtract from one another. And most of the time the error they introduce isn't in the eact same direction at the same time. In fact, it turns out that, on average, the influences are perpendicular to one another. As a result, the average bullet misses the intended POI by a distance equal to the hypoteneus of a right triangle with 1 moa right angle legs. In other words, it is equal to the square root of the sum of the squares of the two influences taken independently, which in this case is √(1 moa)²+(1 moa)²=√2 moa = 1.414 moa.

So, suppose in the case of a gun shooting a bughole, failing to sort cases opens the group up ¹/₈ moa. To the benchrest shooter that's a noticeable effect. But if my gun shoots one moa normally, then the impact of failing to sort the same cases is the square root of the sum of 1² plus ¹/₈², which comes out to 1.0078 moa. Well, your group sizes change more than 0.0078 moa from one to the next, so how do you tell the tiny influence is even there?

The answer is, again, statistical. The tiny improvement may not be reliably measurable, but if you are in a target shooting discipline, where a hole just scratching the next higher scoring ring gives you the higher score, then, every once in a long while, that tiny difference will give you an extra point. It might only be a couple or three times a season, but it will be there. If you don't shoot targets where a scratch gives you a higher score, then it is hard for me to discern what you are getting out of going to the trouble other than by keeping cases of the same lot with the same load history together, you can tell, when several split at the necks or get head separations, that it is probably time to retire the whole lot.
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Old December 22, 2018, 01:22 PM   #27
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what 223 bolt gun were you shooting ?


QUOTE]How much difference on the target you expect to see Rebs ? Last year I took a bolt action .223 with a match grade barrel, aftermarkey trigger and stock. The I weighed out cases, did the water volume thing, sorted by year etc. Weighed and sorted bullets. Went to the range and did chrono tests and grouping tests and at the end discovered no difference in velocity consistency or grouping consistency.

The rifle has repeatedly shot .5 and .6 MOA 10 shot groups at 300 yards with non sorted cases and non weighed bullets. Once put 19 out of 20 into a 1 inch high ribbon at 300 and have posted pics of the groups when load testing

Now may you will be able to separate the difference in accuracy and precision from the noise of gun capability and shooter technique with your AR , but I sure the heck couldn't with my rifle. A 1000 yard benchrester might but I can't.

Anyway have fun sorting, it is a great way to spend a winter evening. If I lived up north I would probably be sorting primers while watching cat videos [/QUOTE]
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Old December 24, 2018, 07:41 PM   #28
9MMand223only
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You can achieve ~1 MOA using mixed brass, weighing nothing, trimming nothing, just using the right powder charge & bullet out of a match bull barrel AR15. If you want better than ~1 MOA, you have to use precise powder charge, bullet weighs, neck sized cases that all have very similar internal capacities.

WARNING, THIS IS OVER BOOK CHARGE:

Accurate 2230 26 grains, loaded to 2.250 using Nosler FP Tipped 55 grain bullet or SIerra Blitzking 55 grain bullet.

Or 24.9 grains VV N133 using Sierra Blitzking 50 grain bullet @ 2.250. Even with mixed brass with different length brass and different internal capacity brass, @ 100 yards you can get ~ 1 MOA. So if you only care about short range, those 2 recipes right there, work nearly universally in every gun I ever seen. Tried them in ~20 different AR15's.
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Old December 24, 2018, 08:52 PM   #29
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Quote:
what 223 bolt gun were you shooting ?
Savage 10 action with accu trigger, Criterion barrel, Choate stock from Midway, 6 - 18 Leupold. Nothing real fancy. Anyone can build one just like it for less than 1000 minus glass and that Leupold was less than $500 with the rebate

here is part of a 3 shot load test at 300 with a couple of sub .5 MOA's and a more substantial 10 shot at 300 with a .6. Nothing against gas guns, I own two myself but they will never be as accurate and precise as a bolt rifles. You have gotten some good advice from some gas gun shooters in this thread. BTW if you want to try heavy bullets don't use a 80 gn bullet seated to magazine length. The 77 SMK is what you want, they work great at magazine length. The NRA shooters at my club use them at 200 and 300
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Last edited by hounddawg; December 24, 2018 at 09:01 PM.
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Old December 25, 2018, 07:48 AM   #30
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Thank you guys for all the information, I appreciate it
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Old December 25, 2018, 08:32 AM   #31
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Rebs,
If your shooting 5.-.6" at 100 yards, and 2.0-2.5" at 300 with an AR, i wouldn't worry about the cases. Your doing good!

As was mentioned trigger, trigger time is going to help you more.

Go to a 600 yard shoot sometime. Kids with open sight AR are kicking my butt!
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