223/556 hornady 10th

[308Loader]

So, looking at load data in the hornady 10th edition. I see data for 223 bolt gun, 223 service rifle, and 556 nato. I am reloading for a Olympic flattop 16" AR15, barrel stamp is 556. Does this mean I should be using the 556 data? What would be the difference in using data for the other two. I think my rifle has a 1 in 9 twist, not sure. Would I be safe using all three data sets?

I've ben loading 25.1gr BLC2 with CCI400 primers and 55gr FMJ-BT mixed brass. Shoots 1" at 100y from my rifle. The reason I ask is I am looking to try different powder and bullet combos for this rifle. This gun is used for target shooting but thinking of some P-Dog hunting this summer (if it ever comes to Minnesota).

[rg1]

I always complain that Hornady is lazy and has published the same data using the same bolt action rifle for the last several manual editions. The most popular rifle, AR's, with the most popular bullet 55 grains, and the most popular powder H335 and they won't retest? I suggest using Hodgdon's H335 data for 55 grain bullets. The Hornady 55 gr. V-Max would be a good bullet to test for prairie dogs. Several great powders for this combination but H335 would be good also. Don't exceed Hodgdon's maximum at 25.3 grains of H335. Hotter than Hodgdon's maximum could be too hot in summer temperatures. The Hornady 55 SP bullet would be a good choice too but may not be as good out past 300 yards. You probably need to sort cases by weight and brand and it's often recommended to use CCI 450's, CCI BR, CCI 41's or my favorite Remington 7 1/2's as they have a thicker cup. Lot's do use CCI 400 with the thinner cup without problems though. Good luck and have fun finding your target, hunting, varmint round. Plus Hornady's data is not realistic and their max data is anemic and does not come close to the velocity they list even in the bolt rifle.

[2ndtimer]

I am quite surprised that anyone is getting 1inch groups at 100 yards with 55 gr FMJ bullets, especially with mixed brass. (3 shot groups? Shot into an inch one time, or consistently?). In any event, using quality bullets from Nosler or Hornady will almost certainly improve your accuracy. As for your listed load of 25.1 gr of BLC-2, it is actually below Hodgdon's recommended starting load for the .223 Rem. with 55 gr bullets (their website lists 25.5 gr to start, with a Max of 27.5 gr.) In my experience, ball or spherical powders tend to provide better accuracy near their maximum charges than minimum. You might be leaving some accuracy on the table, not to mention a couple hundred feet per second in velocity.

[Unclenick]

It depends on the bullet batches. Hornady does pretty well with jacket consistency these days. My .222 Remington would drill all touching holes with their old 50-grain soft points, though, to be fair, a square base formed from the bottom of the jacket cup is easier to make perfect. Still, I've had some pretty fair sub-moa groups from their 150-grain .308 FMJ's.

[Marco Califo]

223 bolt gun, 223 service rifle, and 556 nato. I am reloading for a Olympic flattop 16" AR15, barrel stamp is 556. Does this mean I should be using the 556 data? What would be the difference in using data for the other two.

First, look at the barrel of each of your rifles. The chambering (specific cartridge) will be stamped into the barrel.
A 223 bolt gun is designed to shoot SAAMI spec 233, which can be called commercial ammo.
"223 Service Rifle" is an Oxymoron. 5.56 Service Rifle would make more sense. It is One (223 commercial chamber) or the Other Service Rifle (5.56 chamber). You notice that your AR barrel stamp is 5.56.
5.56 NATO is the same bole caliber, but in these guns the firing chamber is longer than commercial 223. Specifically, it is the throat or Leade, which has slightly longer specs. There are some good diagrams of the chamber dimensions of 5.56 versus 223 here: https://www.google.com/search?q=saam...vaE6HgOMq2BvM:
You will find explanation of the difference searching here http://www.accurateshooter.com/cartridge-guides/223rem/
5.56 ammo is loaded to higher pressures than commercial 223, which is why different data is given. Western Powders reloading guide data includes both, and, the Sierra (5th?) have a separate a article and data for 223 and AR.
A certain rifle may have different chambering characteristics than another rifle in the same cartrigde from the same maker. I have a Savage Axis that will handle longer COAL, as long as 2.3x". I have another Savage 10 that will not close the bolt on anything longer than 2.26". I choose to reload and use separate ammo in the Axis with Hornady 75 gr BTHP, loaded as long as will chamber and fit in the magazine. They wont chamber in my other 223 rifles. I found this length buy using a dummy sized cartridge, with a 55 gr FMJ just started enough to hold it in place, and then closed the bolt completely (with a little force) and seated the bullet to the lands. Eject that cartridge and measure to get the max COAL for that specific gun only. I use that to set up my seating die to just a bit less length.
For your purpose, if the barrel says 5.56, you can uses 5.56 or 223 ammo. 5.56 ammo is not supposed to be used in 223 bolt guns as higher pressures may result.
Barrel twist has to do with heavier bullets and will your rifle stabilize them? 1":9" is the best all around and can do everything from light bullets to 75 gr. There are bullet stability calculators available. You need to know your specific bullet length and some other variables.

loading 25.1gr BLC2 with CCI400 primers and 55gr FMJ-BT mixed brass

[LIST=1]
1. You should use CCI#41 (milspec) primers or CCI 450. Your AR likely has a floating firing pin that can touch the primer out of battery. The 41's and 450's have thicker cups, and other differences to prevent "slamfires". I stopped using CCI 400's when I notice some fired primers had leaked or penetrated. Now I am using Russian 556M primers iintended specifically for 5.56 service rifles.
2. I cringe whenever I hear about people using mixed brass for bottleneck rifle cartridge reloading. Sure you can do that with pistols. But there is a lot more variability in 223/5.56 than in pistol brass. For 7.62/308 it becomes even wider in variation and would be dangerous to load mixed brass. I encourage you to get uniform brass (for example LC any years). Your local range may be able to help you out for free, or you can buy 200 LC Swaged for $22 delivered here: https://www.brassbombers.com/223-556...e-City_c48.htm

[Mobuck]

Unless you use the heavier than normal long range bullets listed on the "service rifle" loads, just load .223 specs and go on with life. The entire 5.56/223 kerfuffle is too confusing for most folks to comprehend.

[std7mag]

From what i know about it the 5.56 normally uses a heavier bullet, has a faster twist, is loaded to a higher pressure, and has a longer throat than 223.

Having a 1:9 twist, 24" barrel, 223 and shooting 69-73gr bullets was a PITA with load data.

[308Loader]

“surprised that anyone is getting 1inch groups at 100 yards with 55 gr FMJ bullets, especially with mixed brass.”

I should clairify, I do sort by headstamp. I have serveral lots of brass with differing headstamps and they get loaded in batches by headstamp. For example I have 300 ppu that will be loaded at the same time, 500 lc will be preped and loaded at a later time and so on. And yes off a bench and bags on a good day I can get MOA.

“Hornady's data is not realistic and their max data is anemic”
“As for your listed load of 25.1 gr of BLC-2, it is actually below Hodgdon's recommended starting load”

yes and yes... hornady seems to allways be on the lighter side. Hodgdon allways starts higher than most published start loads. Witch one is more correct? I dont know, so I start with the lower of the two. For paper punching I have allways had luck with the lower volicity. I do work up my loads to find an as good or better than load. For punching paper if the node on the lower end proforms well, why beat up the gun with a higher volisity. When punching flesh and bone for dinner that is obviousally different. In the hornady book 25.1 is 2900fps, one step above start. Ive not chronographed the actual FPS, it just shoots well out of my gun, and consistante out of several head stamps.

“Lot's do use CCI 400 with the thinner cup without problems though”

I have expereinced one slam fire in 3k rounds loaded. I think it was due to a dirty bolt carrior group. I hadent cleaned in 300+ rounds, pin wasent floating well, kind of gummed up, may have been stuck forward when the bolt closed.

“Specifically, it is the throat or Leade, which has slightly longer specs.”

I do understand this, I think. With the longer run up to the rifling chamber presure is droped some. I do have a hornady tool to measure this, but I just load to mag length or book OAL to keep it simple.

"service rifle" loads, just load .223 specs and go on with life.”

Thats what I fugured is the case, until I tried loading 52gr HPBT at hornadys “anemic” IMR 4895 load. When loading a ladder of their published data I got to 25.6gr and their was little room for the bullet. Compressed load? This data is from their 223 rem bolt gun, page 165,3100fps. This is the fullest case ive ever put a bullet on top of. Safe in a AR platform? It is 2 steps below max. Hence the question, 223 bolt, 223 AR, 556 AR...

Thanks all for the input.

[308Loader]

anyone?

[Marco Califo]

“Lot's do use CCI 400 with the thinner cup without problems though”

I have expereinced one slam fire in 3k rounds loaded. I think it was due to a dirty bolt carrior group. I hadent cleaned in 300+ rounds, pin wasent floating well, kind of gummed up, may have been stuck forward when the bolt closed.

Your experience does not mitigate the risk of slamfires. In other words, I do recommend using the recommended primers (and not using 400's).

[308Loader]

So bottom line? 223 rem is 223 rem, service rifle or bolt gun. 556 is good with all 223 loadings. obviously start at start (what ever that published data might be) and work up. I don't think the 26.4 @ 3100fps will fit in the case, one step below max in hornadys book.

If I look at 55gr bullets from 223 to 556 in blc2, start in bolt is 24.4@2800fps in 556 it is 22.3@2800fps. Is this due to barrel length or twist or what? Those of you that call out powder manufacture start loads, wouldn't this make a difference?

To say a start load is X, would it not be depend on several other factors? With a new loading I try to reference 3 different published sources start loads, and start at lowest start. Moving towards max I'm just looking for tight groups (pressure & harmonic nodes?) and pressure signs on the cases & primers, right?