Lee Loader

Other than the 556 case being a little heavier and thicker walled (so less room for powder) is there any other difference between the two rounds? Same bullet, primer etc.? Do the reloading manuals (my lee manual is still on the way) make a distinction between the two? I have some Lake City once fired brass and want to load it. I understand about the crimped primer pocket prep.

For reloading purposes the slightly thicker wall of some 5.56 cases may require adjusting the powder down slightly to get the same velocity. Not all 5.56 brass is made to the same NATO specs and those specs have tolerances so if you really want consistency trim cases to the same length after sizing and separate by weight. The primer pockets may also need swagging or reaming to remove the primer crimp. I will not get into the internet argument of whether it is safe to fire a NATO spec 5.56 round in a 223 chamber. I haven't had to worry as I haven't had the occasion to try and regardless my bolt rifle says .223 - 5.56 on the barrel. Surprisingly even with the longer 5.56 leade, hence jump it is sub-MOA even with .55 grain bullets. It gets even better with 65 to 69 grain ones.

Technically there are other minor differences. I don't buy factory .223 REM nor do I use .223 REM brass. I don't have any .223 REM bolt guns so I only use 5.56X45 military cases that I spend time on prepping.

For middle-ground "normal" loads, you will likely see little difference.

Thanks for the replys, both of my AR's have wylde chambers. I have 69 grain bullets that I plan to use with the Lake City brass that I have. But, I also have quite a bit of manufactured ammo that will yield some 223 brass to load. I agree that the 69 gr. bullets seem to be very accurate from all the testing that I have seen. I am not sure I understand this completely, but from what I can tell hollow point bullets are more accurate than plain jacketed bullets. I have not done any real in depth research on this. I am sure there is some aerodynamic property that I don't understand. To me it seems that the hollow point would create more drag and cause a larger chance of the bullet going offline. Any thoughts on this?

As good an explanation as any.
https://www.alloutdoor.com/2018/08/21/h ... -accurate/

For years I have shot Sierra Match King boat tail HP bullets in a couple of 223s and 6.5mm rifles. As close as I can shoot the equivalent soft points are very slightly less accurate then the Match Kings. We're talking 10ths of an inch here. Significant to the bench rest shooter, but for fun and game doesn't matter. Sierra advises against using the MKs on game. I've never tried them on big game and ground hogs and coyotes don't seem to notice a difference as long as I do my part, DRT.

Enjoy either, they test your rifle and your skills.

Stay well, be safe, make smoke,

One of the most accurate bullets in my bolt rifle is the Hornady 60 grain SP Varmint #2270. I would have thought otherwise but after shooting a couple of hundred there is no doubt. Pleasant suprises like this is one of the reasons I enjoy handloading.

Macd wrote:As good an explanation as any.
https://www.alloutdoor.com/2018/08/21/h ... -accurate/

Thanks for that article. It does a really good job of simply explaining the difference. I am not a bench competition shooter, but I do like to compete with myself and experiment with different companies ammo and powder load sizes on manuf. ammo. That is part of the reason that I wanted to start reloading to be able to safely experiment with powder and bullets to develop more accurate ammo.

I realize that a 223/556 is not going to be the most accurate rifle possible and I will probably end up with a bolt rifle in the future. I do have a match grade barrel on one of my AR's and it is pretty accurate compared to my other rifle barrel. Just an off the shelf fairly expensive barrel, but was not advertised as a match barrel.

Even cheap bullets like the 2266B I mentioned can be accurate when driven by the right load in a good rifle.

Nice groups, I'm jealous. I can get groups like that from 7 yds with my 9mm on a really good day.
http://www.lee-loader.com/posting.php?m ... =45&t=3210#