I will preface this question by stating that I have been reloading for about 15 years now, but I am a noob to reloadaing .223/5.56. I purchased my first AR last summer and just started reloading for it around November.
I purchased once-fired 5.56 (Mostly Lake City, mixed batches) and have been loading some M855 clones to get comfortable working up loads for my rifle (LE 6920).
My question is, after doing some research, I know that .223 brass is usually thinner than 5.56 brass. The thicker walls of 5.56 brass is indicative of increasing chamber pressure due to reducing case volume. Since a 5.56 chamber has a longer lead than a .223 chamber, has anyone had any success working up 5.56 pressure loads with .223 brass when used in a 5.56 chambered rifle.
I have enough 5.56 brass to last me a while, but since I can find new .223 brass cheaper than 5.56, would that even be an option for the future?
I realize this is a delicate subject is is very relative to the rifle in question. I am shooting a 5.56 chambered 6920 with a16 inch bbl and carbine length gas system.
Mil brass is not thicker than commercial brass. LC cases are some of the lightest out there.
You can find some heavy commercial cases, if anything these need to be segregated into separate lots. But most Win/Rem/LC cases run around 92-95 grains.
Do you have a good chrony to confirm velocity along with the visual pressure inspections on the case??
You can certainly work up hot loads with any case but you have to balance this with the various quality of the 223 brass used & case volume as mentioned. I would not assume case volume for any 5.56/223 case. Just work up as you normally do.
I’m hoping to test some hotter 223 / 75gr loads in the next month or two & will be comparing the cases / brass quality. Right now I have the following 1x fired cases:
Winchester M855 5.56
Winchester .223 (this is from the leo Ranger 64gr power point)
PRVI M855 5.56 brass
PRVI 223 (from their 69gr match)
Will be using reloader 15 and hornady 75gr hpbt to keep things simple. My current load is a moderate but very accurate load in the sbr and varmint ar’s currently being used.
No, I’ve never had a chrony. All my pressure indications have been with visual indications associated with the cases/primers.
Molon, thanks for the chart on case capacities. That was pretty eye-opening. I don’t need any more brass for a while yet. But I will certainly take that into account when ordering more.
