Reloading .223 with mixed head stamps.
- Thread starter chasep255
- Start date
Depends how good your AR is. If you have a half moa gun, you might see a difference. Fortunately for you, .223 cases seem to differ less in internal capacity from make to make than .308 or .300 Win Mag, to name a couple where the differences can be significant. So your potential problems are limited.
Nonetheless, when it comes to maximum accuracy you may find different makes have different wall thickness that affects bullet grip and other factors like that which can change your powder burn timing a little. There can also be differences in overall brass hardness. Federal is famous for being a little on the soft side and having its primer pockets widen prematurely if it isn't loaded on the mild side. Don't know about their mil-spec version, though.
I think most of us who shoot matches automatically segregate brand, by the number of reloadings, and by what gun we fire it in. That keeps things pretty similar from one set of loads to the next. But a lot of this is habit more than a matter of proven necessity in each case.
Nonetheless, when it comes to maximum accuracy you may find different makes have different wall thickness that affects bullet grip and other factors like that which can change your powder burn timing a little. There can also be differences in overall brass hardness. Federal is famous for being a little on the soft side and having its primer pockets widen prematurely if it isn't loaded on the mild side. Don't know about their mil-spec version, though.
I think most of us who shoot matches automatically segregate brand, by the number of reloadings, and by what gun we fire it in. That keeps things pretty similar from one set of loads to the next. But a lot of this is habit more than a matter of proven necessity in each case.
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m&p45acp10+1
New member
Probably not. I load with mixed head stamp brass. In fact my brass is almost all range pick up. So that means lots of different head stamps. I just worked up loads using Dan Newbery's OCW method and while someone that is a way better shot than me would be able to notice a differance I have as of yet to notice. I get acuracy of better than half MOA with a bipod, and a sand bag under the butt of the stock.
4runnerman
New member
I agre with M&p45 here. I load mixed head stamp also. I do make sure they are with in 1 gn in weight of each other and trim all cases to 1.752. I have seen no difference so far.
Edward429451
Moderator
I think trimming them all to a uniform length does more than sorting headstamps in 223.
I sorted a bunch of range brass by headstamp. I then prepaired all the cases in the same manner and worked up loads in four differant brands of brass. Turned out that 25.0 grains of Benchmark is the sweet spot reguardless of what brand of brass I'm using. But I sort all of my brass by headstamp anyway
That was Hornady, Winchester, Remington, and Federal brass.
That was Hornady, Winchester, Remington, and Federal brass.Next question is, since you have a nice round number on your powder charge, how big were the steps in powder charge you tested? Figure you can sometimes run right over a sweet spot in half a grain in a case that small, so quarter grain steps (+/- 0.2 or 0.3 grains) either side of that value might yield an even better result.
If the results get tight enough, you might start to see the difference in cases. That can take some pretty tight shooting. The reason is that group diameters produced by different error sources in isolation don't add up when you combine the error sources. Instead they add the areas of the group sizes produced by the contributing sources in isolation. So, new group diameter equals, on average, the square root of the sum of the squares of the contributing diameters. Adding a 1/4" group error source to a 1/2" group error source only gives you a group 0.56" across, so you might not realize there's any real difference. Bottom line: A small error source can be very hard to see until other error sources have been fought down.
There is a statistical method called a T test that can help you tell if two groups have a statistically significant difference or not. For small error corrections, that may be the only way to tell clearly. Consider that 1/2" group diameter was grown by not quite 1/16" by adding in the 1/4" error source. You might well be very pleased by either group, yet if you shoot a 50 round National Match course, ask yourself how many times you gain a point because your bullet scratched the next higher scoring ring, and figure that small difference can take some of those away from you. It might only be a point or two or maybe only a lost scratch X or two, but matches are often won or lost on those kinds of differences.
If the results get tight enough, you might start to see the difference in cases. That can take some pretty tight shooting. The reason is that group diameters produced by different error sources in isolation don't add up when you combine the error sources. Instead they add the areas of the group sizes produced by the contributing sources in isolation. So, new group diameter equals, on average, the square root of the sum of the squares of the contributing diameters. Adding a 1/4" group error source to a 1/2" group error source only gives you a group 0.56" across, so you might not realize there's any real difference. Bottom line: A small error source can be very hard to see until other error sources have been fought down.
There is a statistical method called a T test that can help you tell if two groups have a statistically significant difference or not. For small error corrections, that may be the only way to tell clearly. Consider that 1/2" group diameter was grown by not quite 1/16" by adding in the 1/4" error source. You might well be very pleased by either group, yet if you shoot a 50 round National Match course, ask yourself how many times you gain a point because your bullet scratched the next higher scoring ring, and figure that small difference can take some of those away from you. It might only be a point or two or maybe only a lost scratch X or two, but matches are often won or lost on those kinds of differences.
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603Country
New member
This is very interesting information you guys have laid out. I'll have to do some experimenting with the mixed 223 brass that I have. Now that I have a favorite 223 load, I'll take my mixed brass and give it some prep that's equal to the prep I've done on my 'select' Nosler brass. I will weight sort it, but will not separate the Remington from the Winchester. I just can't believe that it'll shoot as well as my 'good brass', but I'll give it an honest comparison and hope that it does. I'm not doing any competition shooting, but just nailing coyotes and pigs at typical ranges from 50 yards to 250 yards. If the mixed brass shoots almost as well (no worse than 3/4 inch groups at 100), that'll do fine for what I need.
Neck tension, neck wall thickness uniformity both for tension and bullet centering repeatability, degree of flash hole burring (matters to spherical propellants, but not so much to stick powders, IME). consistent primer pockets to help primer seating be more uniform, ease with which the sizing die expander pulls the neck off-axis. Total water capacity of the case affects peak pressure and final velocity and barrel time, but it can be very hard to positively detect those differences until you get beyond 300 yards, though. If you have a touch load, that capacity difference can drift one off a sweet spot, but I don't like touchy loads and avoid them because other things can drift them off a sweet spot, too (like change of ambient temperature).
Merrill Martin made a case for wall thickness below the neck affecting accuracy. What he and the late Roger Johnston called a "banana shaped case". But I can't say I've seen this error. Turning the necks to uniform them seems to do about as much for me as picking out uniform case walls.
Merrill Martin made a case for wall thickness below the neck affecting accuracy. What he and the late Roger Johnston called a "banana shaped case". But I can't say I've seen this error. Turning the necks to uniform them seems to do about as much for me as picking out uniform case walls.