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Discussion Starter #1
I’ve been handloading for about 6 years now, mostly 9mm, 357 Magnum, and 223 Remington, but a little 45ACP, 30-30 and just started 308 Winchester a few months ago. This issue concerns the 223. My standard load is 23.5 grains of H335 with a 55gr bullet seated to 2.230. I never really paid much attention to brass head stamps as this load is not at maximum and it shoots fairly accurately in my Ruger American (22” barrel with a 1:9 twist). I have noticed a wide swing in velocity at the muzzle, and attributed that to the various brass manufactures as all other conditions are equal (trim length, powder charge, seat depth, etc).

So, I decided to run some velocity tests with different head stamps and all other factors being identical. I loaded 5 each of Lake City, PMC, 2 different Federal, and Military brass with my standard load. All brass trimmed to the same 1.750 length. All powder charges were weighed by hand. All had the same CCI 400 primer. All bullets were weighed at 55gr, and all were seated to 2.230. The results are below.

Mil – average 3031 with a 100 FPS difference min to max

Lake City – 3022 average with 96 min-max

PMC – 2987 average with 80 min-max

Federal – 2988 with 132 min-max

Federal cartridge – 2954 average with 128 min-max

For grins, I also checked some commercial PMC. Average was 3144 with 104 FPS difference min-max.

I understand the differences between averages attained with the different head stamps. My concern is the spread of velocities within each group. With all factors besides head stamp being the same, shouldn’t my spread between minimum and maximum velocities be much less? Is this as good as it gets, or am I missing something?
 

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As I was reading your post I thought to myself; "that is a pretty big spread". Then I stopped and thought. First question that came to mind is what was the standard deviation? (max deviation can be a matter of a single flyer; standard deviation will give you an average) Next I thought about bullet quality; are you weighing the bullets? One last thing; on the LC brass I group by date myself; did you? (not that it would affect the other brass groups, just curious)

If the powder charge is consistent then what else if affecting velocity? Bullet weight jumps to mind. Starting with a clean bore for each group comes to mind. And of course weather conditions come to mind. For instance; leaving your magazine laying in the sun while shooting another group can raise the temp of the ammo in the magazine enough to affect velocity. Any outside force that affects velocity can not be counted upon to do it evenly to each round in the magazine.

Personally I only load one type of brass for 5.56 (lake city)

EDIT: Oops almost forgot; how reliable is your chronograph? They are not all created equal. Might want to try this with a different one.
 

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Discussion Starter #3
I weighed each bullet before loading, and all were 55 gr as advertised. I did not group LC brass by date. I did not clean the bore between groupings; however, each string had faster 1st/2nd shots followed by slower remaining shots. I did allow the barrel to cool between 5-shot groups. Magazines were loaded one at a time from a box of ammo kept in the range bag, out of the sun.

Could be the chrono. It's a Caldwell. I have had good results with it checking other calibers.

So I went back to my figures and calculated SD for each head stamp. Results below:
Mil - 46.6
FC - 60
Fed - 45
PMC - 38.5
LC - 58.9
SD for my commercial loads was 43.5

I'm not completely certain on the origin of the brass...some is likely range pickup. I know the Mil is range pickup and likely once-fired. I also now have about 200 rounds of once fired commercial PMC and Federal that I will be reloading and testing soon.
 

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My recollection is that military brass tends to have less capacity. You can weigh the water capacity of a batch of your military cases, with the same headstamp (manufacturer and year), average, and compare to a batch of the commercial cases with the same headstamp. My recollection is that reloading manuals used to (may still) recommend reducing the loads by 10% for military brass. Apologies if I missed something in skimming through your original post and the reply(s) that makes my observation irrelevant.
 

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Standard deviation still seems a little high to me (not outrageous). Some of it might be the Chrono's accuracy but unless you have another chrono to test with I wouldn't worry about it for now.

Two things I would try, to isolate where the inconsistency is coming from. I would try to chrono my loads from a bolt action rifle to see if the SD tightened up. The other is; with the velocities you posted these are a fairly light load; I've never used H335 myself but I'm guessing you have some empty space in your cases. You could try topping them off with cream or wheat or similar which should help keep burn / ignition of the powder consistent. Beyond that you need someone smarter than me LOL

EDIT: The bolt gun comment I made, made me realize you never mentioned what you were shooting your loads in; I just assumed an AR. If it is an AR and you loads were more consistent out of a bolt gun that would point ME toward the ARs gas system.
 
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Standard deviation still seems a little high to me (not outrageous). Some of it might be the Chrono's accuracy but unless you have another chrono to test with I wouldn't worry about it for now.

Two things I would try, to isolate where the inconsistency is coming from. I would try to chrono my loads from a bolt action rifle to see if the SD tightened up. The other is; with the velocities you posted these are a fairly light load; I've never used H335 myself but I'm guessing you have some empty space in your cases. You could try topping them off with cream or wheat or similar which should help keep burn / ignition of the powder consistent. Beyond that you need someone smarter than me LOL

EDIT: The bolt gun comment I made, made me realize you never mentioned what you were shooting your loads in; I just assumed an AR. If it is an AR and you loads were more consistent out of a bolt gun that would point ME toward the ARs gas system.
Ruger American, 22inch barrel, 1to9 twist, was what he had indicated.
 

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Military brass is thicker than commercial so as was suggested, it would have less capacity _when all of it is new_. Without knowing how much your brass had been fired, that's about all that can be said about the brass you are using. There are lots of other things that could be going on, but since the LC/mil seems to be at a higher velocity than the commercial, that's where I'd start looking. There are various methods to measure internal case volume, but have you weighted and weight-sorted the cases? If not, that might be a starting point.
 

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Remington brass will not hold my charge but LC brass will.Varget powder.
That really doesn't offer enough information. For example, if the LC brass had been repeatedly fired (and possibly trimmed or ???) and the Remington was new commercial, that could easily explain things. Again, what does the scale say? If the cases have been fired in the same chamber, the external diameters of all the cases should be the same - the lengths could easily be different, but that can be dealt with by measurements and math - and the weights are a lot easier to measure than _precise_ internal volumes across multiple cases, so once you/we have those, you/we can proceed.
 

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Some things to try

1)Take some of the same headstamp cases fully prepped and weigh out 10 that are within one grain. See if that makes a difference.

2) Allow shots to cool between each of the five, not just between groups

3) those velocities are a little low for a 22" bolt gun except for the PMC. Up the powder charge in small increments to see if the powder likes to run a little higher pressure.
 

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Discussion Starter #13
Have some once fired FC and PMC that I resized and deprimed. Measured and weighed it into 4 groups. Hi/lo 92 gr and 93 gr. Will load these up...May up the charge to 24 gr of H335.
Also will let the barrel cool between shots.
Don’t know when I’ll be back at the range but I’ll post results.
 

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Check the flash holes on your brass for concentricity, especially the PMC. I've had more off center flash holes with PMC and Fiocchi than all others combined. Probably not an issue but takes only seconds.
 

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Let's go shoot some, we dont want to wound anything.
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First I am not a reloader. I plan to be and am absorbing the information from everyones knowledge. But I wonder if using new unfired brass would help solve the variation in velocities?? Then if it is new brass, perhaps another powder.
Then could it point to the barrel. I have a Ruger American and they are accurate. I remember Sum Guy talking about a problem with a gun that was cured with a really good barrel cleaning for a man that shot in competitions. I thought that I probably need to give my hunting guns a better barrel cleaning after hunting season.
 

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The cleaner the barrel the more accurate the gun
Sum Guy cleaned a gun of mine I thought was clean, It was not. Lead had accumulated in the grooves
After cleaning it was a new gun

As far as your choice of powder, look in the lyman 49th edition at the different powder options for your gun. They have the powder the engineers have decided to be the best highlighted

I wished we lived closer. I would be there for ya
 

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Discussion Starter #17
Check the flash holes on your brass for concentricity, especially the PMC. I've had more off center flash holes with PMC and Fiocchi than all others combined. Probably not an issue but takes only seconds.
I did that with the brass I'm prepping now...with a magnifying glass. All look good, no burrs.
 

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Discussion Starter #18
The cleaner the barrel the more accurate the gun
Sum Guy cleaned a gun of mine I thought was clean, It was not. Lead had accumulated in the grooves
After cleaning it was a new gun

As far as your choice of powder, look in the lyman 49th edition at the different powder options for your gun. They have the powder the engineers have decided to be the best highlighted

I wished we lived closer. I would be there for ya
I plan on letting the barrel cool between shots, with a good cleaning between each 5-shot group. Then a couple of fouling shots before starting the next group.
I may eventually look at other powders after I use up the H335 I have on hand. I do have some Rem7.5 primers I may try.

Thanks for the offer of assistance.
 

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I'm in Poplarville and would offer the services of my reloading room (and myself), but I've read through the entire thread and can't offer more than what's been said. Since you've already said that you're measuring your powder by hand, I can only suggest - as others have - to segregate your brass by manufacturer and weight each individual bullet to identify outliers.

Best
Doc
 

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Discussion Starter #20
I weighed and measured about 200 PMC and FC cases tonight. I grouped lengths of 1.740-1.745 and 1.750-1.755. Then I weighed them all and separated into 6 overall groups. They are all primed and ready to load one night this week. Individual bullets, Hornady 55 gr FMJ-BT, will be weighed. I will also trickle up loads of H335. I think I will have them as consistent as possible.

Thanks for the offer.
 
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