Mixing 223 and556 brass?
- Thread starter Baer45
- Start date
Internal capacities of the different headstamps can be measured if you'd like to know for sure. Otherwise, I'd test the load you want to use in each headstamp. A mid-range load might work, bit it really depends on your rifle and how hot your load is.
Lots of load data on this site; I'd recommend a search.
Lots of load data on this site; I'd recommend a search.
Crimped 5.56 brass is a pain in the butt. I used to just give them away or toss them. I quit buying military brass/ammo because of it. I don't need any extra steps or extra tools.
Lake City 5.56 is good brass, but had a lower internal volume. I would keep you charges lower until you see how your first reload turns out.
Lake City 5.56 is good brass, but had a lower internal volume. I would keep you charges lower until you see how your first reload turns out.
jepp2
Gold $$ Contributor
Agree with LC being good brass, the lower internal volume claim has never been true. Here is the actual data:
Cemetery21
NRA Life since 1975
As the chart above shows, there is a little internal capacity difference in various 223/556 headstamp brass, just as there is likely to be some difference in any other caliber. And, as mentioned, in 223, it probably doesn't matter for "plinking" loads if not near max.
Mixed brass can affect accuracy, as most of us know.
Mixed brass can affect accuracy, as most of us know.
From you're perspective of reloaded to make plinking rounds the key difference between 5.56 brass and 223 brass:
1) Crimped primers in 5.56, but this isn't always done. As a precaution it is best to assume all 5.56 as crimped. You'll need to swage the primer pockets to make uniform and remove any swaying/crimping. Not a big deal... just an extra step. Some progressive reloading presses have a stage built in to handle this issue.
2) Sealed/lacquered primers in 5.56, which is done to make case water tight. Most common appearance is a splash of red enamel across bottom of case. Best practice is to toss these into recycle bin because likely to break tip off depriving rod or simply punch through the bottom of primer without removing it from spent case.
3) Sealed/lacquered bullets in 5.56 to make water tight. Reside on fired cases appears as black hard resin/tar around neck/mouth of case. This something more than the typical soot or carbon found on fired case. It can be remove with Q-tips and Acetone, but its not worth the effort. Deposit in recycle bin.
4) Once-fired military brass that you buy online - Need to check for irregular swelling along case body from being used in full auto, belt-fed weapon.
Lake City is great... not likely to find Lapua laying on ground. Keep and reload the major brands (LC, Federal, Winchester, Hornady, RP, PMC, Wolf, etc), and recycle all of the oddball, unrecognizable headstamps. Since you're making plinking ammo, just resize spent brass with 223 full body die, swage, and trim to uniform case length like 1.750". You can group by headstamp and even year, and reload in batches. Just remember to lube before resizing to avoid stuck case while resizing brass from random chambers.
1) Crimped primers in 5.56, but this isn't always done. As a precaution it is best to assume all 5.56 as crimped. You'll need to swage the primer pockets to make uniform and remove any swaying/crimping. Not a big deal... just an extra step. Some progressive reloading presses have a stage built in to handle this issue.
2) Sealed/lacquered primers in 5.56, which is done to make case water tight. Most common appearance is a splash of red enamel across bottom of case. Best practice is to toss these into recycle bin because likely to break tip off depriving rod or simply punch through the bottom of primer without removing it from spent case.
3) Sealed/lacquered bullets in 5.56 to make water tight. Reside on fired cases appears as black hard resin/tar around neck/mouth of case. This something more than the typical soot or carbon found on fired case. It can be remove with Q-tips and Acetone, but its not worth the effort. Deposit in recycle bin.
4) Once-fired military brass that you buy online - Need to check for irregular swelling along case body from being used in full auto, belt-fed weapon.
Lake City is great... not likely to find Lapua laying on ground. Keep and reload the major brands (LC, Federal, Winchester, Hornady, RP, PMC, Wolf, etc), and recycle all of the oddball, unrecognizable headstamps. Since you're making plinking ammo, just resize spent brass with 223 full body die, swage, and trim to uniform case length like 1.750". You can group by headstamp and even year, and reload in batches. Just remember to lube before resizing to avoid stuck case while resizing brass from random chambers.
Last edited:
searcher
Gold $$ Contributor
In my experience, a .556 brass-based load will, on average, require about 3/10th - 4/10th grain less powder to achieve the same velocity as a .223 brass load. You can safely mix the brass as long as you are using a load that is safe for ALL of the brass - which, to me, would be between 5% and 10% off max book recommendation. Because your velocities will be different from each piece of brass (ie: mil vs. non-mil, brand name, lot, etc.), your grouping will typically be larger than if using all the same lot. If you using for plinking and blasting - it makes little difference. If extreme accuracy is wanted - best to at least sort to same.
Save $$ By Using Lake City 5.56x45mm Once-Fired GI Brass
http://bulletin.accurateshooter.com/2019/10/save-by-using-lake-city-5-56x45mm-once-fired-gi-brass/
Accuracy Potential of Mil-Surp 5.56×45 Brass
So, how accurate can previously-fired GI surplus brass be in a good National Match AR-15? Well, here’s a data point from many years ago that might be of interest. A High Power shooter who wrote for the late Precision Shooting magazine took a Bill Wylde-built AR match rifle to a registered Benchrest match. His first 5-round group ever fired in a BR match was officially measured at 0.231″ at 200 hundred yards. This was fired in front of witnesses, while using a moving target backer that confirmed all five rounds were fired.
He recounted that his ammo was loaded progressively with factory 52gr match bullets and a spherical powder using mixed years of LC brass with no special preparation whatsoever. Obviously, this was “exceptional”. However, he had no difficulty obtaining consistent 0.5-0.6 MOA accuracy at 200 yards using LC brass and a generic “practice” load that was not tuned to his rifle.
If you look at the chart below you will see that the Lake City brass is above average in quality and uniformity. And Remington and Winchester cases have larger case weight variations.
http://bulletin.accurateshooter.com/2019/10/save-by-using-lake-city-5-56x45mm-once-fired-gi-brass/
Accuracy Potential of Mil-Surp 5.56×45 Brass
So, how accurate can previously-fired GI surplus brass be in a good National Match AR-15? Well, here’s a data point from many years ago that might be of interest. A High Power shooter who wrote for the late Precision Shooting magazine took a Bill Wylde-built AR match rifle to a registered Benchrest match. His first 5-round group ever fired in a BR match was officially measured at 0.231″ at 200 hundred yards. This was fired in front of witnesses, while using a moving target backer that confirmed all five rounds were fired.
He recounted that his ammo was loaded progressively with factory 52gr match bullets and a spherical powder using mixed years of LC brass with no special preparation whatsoever. Obviously, this was “exceptional”. However, he had no difficulty obtaining consistent 0.5-0.6 MOA accuracy at 200 yards using LC brass and a generic “practice” load that was not tuned to his rifle.
If you look at the chart below you will see that the Lake City brass is above average in quality and uniformity. And Remington and Winchester cases have larger case weight variations.
Last edited:
jelenko
Gold $$ Contributor
The chart above [which I copied and pasted from the post by jepp2 says LC does not always have lower case volume than commercial.
Ned Ludd
Silver $$ Contributor
I'd suggest measuring water volume of 5 or 10 pieces of each, then comparing your results to the table provided above to get some feel for "how different" the internal volumes really are. If the difference in the mean volumes of the two types is greater than the range (ES) for either set (meaning the range of internal volumes of the two types of brass don't overlap), you can do a similar test by loading and firing several of each. Using a load that is "safe" in the set of brass that has smaller internal volume, fire 5 to 10 rounds loaded identically and measure velocity. For a small effort and one trip to the range, you should have a very good idea how each type of brass behaves and determine whether there is a sufficient difference in internal volume that mixing them together is probably not a good idea.
The concept or reloading for me is to get better quality ammo. Mixing brass using the same powder charge tends to negate that.
Cemetery21
NRA Life since 1975
^^ I'm with Mr. Milisock on that. But not every reloader has to be for every purpose.
The most particular man I knew (RIP) once bought a bucket of range brass from me to load doomsday 223. He didn't sort or prep for that, but he used nothing but the best for his other purposes.
The most particular man I knew (RIP) once bought a bucket of range brass from me to load doomsday 223. He didn't sort or prep for that, but he used nothing but the best for his other purposes.
This common misunderstanding apparently stems from LC7.62x39 brass, which is noticeably heavier than some commercial .308Win.
Edit: oops! 7.62x51. . .
LC5.56 brass volume is in the pack with the rest of the commercial brass, but the pockets are much tougher. It lasts 3x longer than any other headstamp I've tried.
Last edited:
Cemetery21
NRA Life since 1975
7.62 Nato 7.62 x 51
searcher
Gold $$ Contributor
I have no doubt that varied lots of any make can have different volume - let alone differences in brands. If I weighed all my lots of the same brands posted on the chart - they would no doubt differ from the chart. As I stated - that was in my experience. I might add that I use Lake City and this was compared to Remington and Winchester commercial brass that I also shoot. Again, lots of mine may be different from that other people. The point is that everything can be different and if he is mixing brass - better make allowances for these differences. It is also interesting to note that just because one brass has less internal volume - it does not always produce higher velocity with the same amount of powder.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.