Reloading .223 and 5.56

[smoke-wagon]

Hello, I haven't purchased any manuals yet but I plan to start reloading by the end of the year. My question is this, I have fired both .223 and 5.56 and I've mixed the brass. I know the 5.56 has slightly thicker walls than .223 so will I need to separate and have different loads for .223 and 5.56 cases or will the loads be comparable? I assume they will be separate but I figured I'd ask JIC. Thanks.

[dkf]

Here is a reloading guide you can download free from Ramshot.

http://www.ramshot.com/wp-content/up...ec_1-23-14.pdf
http://blog.westernpowders.com/wp-co...date7-8-15.pdf
http://blog.westernpowders.com/wp-co...date7-8-15.pdf

You will notice in the Ramshot data (and some others) they list data for lower .223 pressures and then higher pressure loads for 5.56 rifles. I'll use .223 or 5.56 brass for lower pressure .223 loads but only use 5.56 brass for the higher pressure 5.56 loads. You want to start low and work your way up regardless. You will notice the case volume difference between .223 and 5.56 brass depending on which powder you use.

[smoke-wagon]

That makes sense, thank you.

[cephas]

What dfk said. Use .223 data and work up. I've found somewhere in the middle makes good plinking loads. Don't know if your aware or not that the 5.56 brass probably has crimped primers. Not a big deal but will be another step in the process.

[dkf]

One thing to keep in mind with the .223/5.56 in semi autos like the AR is proper primer selection. I found I can use CCI standard small rifle primers for mild loads at .223 pressures but notice signs of piercing (dimples in the center)before I get to listed max loads for .223. The 5.56 listed loads are even hotter. So for most of my .223 or 5.56 laods I use a BR4 CCI primer which has thicker cup. The military primers have a thicker cup too. With the BR4s I can run up to max loads.

[Hawk]

I ignore what brass I'm using and load them all with the same powder drop. Note: I'm reloading for a AR with a Wilde chamber and dropping 24gns of H335 for 55gn bullet. I've not noticed any difference in accuracy, of course I'm using iron sights at 200-yards with a SR target and 2-3 MOA groups. Now if I was shooting a .223 chambered varmint rifle with a scope near max loads, I'd select cases more carefully.

[JoshIronshaft]

I don't sort brass between 223 and 5.56 either. Just have a load I know is safe for both. One evening I took a sample of 20 different headstamps, about 60% 5.56 and 40% 223. I checked their volume with water, 5 times each. The range of volume in the 223 cases overall was a wider range than any volume difference I found in the 5.56 case. I don't have the specific numbers in front of me, but for example, if the lowest volume 223 case held one ounce and the largest held 3 ounces, all the different 5.56 cases held 2 ounces. Hope that makes sense.

[Twoboxer]

. . . I know the 5.56 has slightly thicker walls than .223 so will I need to separate and have different loads for .223 and 5.56 cases or will the loads be comparable? I assume they will be separate but I figured I'd ask JIC. Thanks.

- "556 brass" does not necessarily have thicker brass walls than "223 brass". Some do, some do not compared to some "223 brass".

- All 223/556 brass can handle 556 loads. It is your firearm's chamber that decides whether a 556 load would be a good idea.

- After firing in YOUR chamber and trimming to the same length, measuring the water capacity of cases gives you a useful basis for comparing THAT BATCH/YEAR of THAT BRAND brass to others.

- Many times (and over the shorter term almost all) different batches of the same BATCH/YEAR STAMP/BRAND of brass will have essentially the same water capacity.

- Sorting by headstamp is a reasonable way of grouping brass into batches of consistent wall thickness.

- Thicker brass walls do reduce the volume of your chamber more than thinner walls and will increase the pressure of any given powder charge . . . all else being equal.

Assuming your chamber is 556 rated, and assuming you are not working near the top of the 556 pressure range, difference in brass will not be significant enough to cause a safety or even a pressure issue. However, performance (velocity, group size) may change. To the extent that becomes a bother to you, you may benefit from separating your brass by headstamp and developing different loads.

Again assuming your firearm is 556 rated, and assuming you are working at or near the top of the 556 pressure range, more care could prove useful to avoid over-pressure situations. While they may not become safety issues, you're likely to be hammering your firearm and components for little or no practical gain.

[smoke-wagon]

Thanks everyone. The barrel is a colt 6520 lightweight pencil profile rated for 5.56.

[BobGun]

I also do not sort brass for my plinking loads. For my heavy barrel I have 200 pieces of Norma brass which is very good. This gun shoots 1/2" five shot groups at 100 yards.