I've been using the .223 Remington data to load for my AR's, a few tenths off maximum charge and they function well. Do any of you load yours hotter using the 5.56 NATO data? Just curious.
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I've been using the .223 Remington data to load for my AR's, a few tenths off maximum charge and they function well. Do any of you load yours hotter using the 5.56 NATO data? Just curious.
I’ve loaded AA2200 data powder to 25 gr. Over 3200 fps with .223 commercial cases and .224 jword. Function well but group spreads out, dropped back to 24.5 and set jump to .010 off rifleing and got best groups.
I load 77gr bthp to max with 8208xbr but everything else down a half grain or so. Really if it works, it’s accurate and you’re not trying to shoot through a bunch of AK mags strapped across a bad guys chest, .223 level is just fine.
The latest Hornady manual update lists some 5.56 level loads if you are inclined.
I downloaded Western Powders manual and it has an extensive 5.56 NATO section. Same bullets and same powder but much hotter loads. Make me think I can easily load up to commercial max levels chasing accuracy. I've got some 68 gr. Hornady match bullets and some 2460 and Ramshot Tac powder coming. Will see where I wind up. That .010" off the lands has worked well for me in .308 and .243. The Hornady bullets do not have a cannalure so I can adjust the oal.
The SAAMI MAP for the 223 Remington is 55,000 psi. US milsurp does not adhere to SAAMI specifications and does load to higher psi, both M193 (55 gr FMJBT) and M855 (62 gr FMJBT Green Tip).
I have been loading and shooting milspec level psi with appropriate bullet weight/length for the barrel twist in my bolt guns (Winchester, Remington and Savage) and gas guns (ARs, Mini14s, and others) since the early '70s. I use SAAMI 223 Remington level loads in my Contender Carbine and Savage M24 break open rifles. Cases are mostly LC with WSR or CCI 450 primers used.
I have pressure tested the following using a 21" barrel:
Remington 50 gr HP factory; 3280 fps at 52,900 psi
US M193 (55 gr FMJBT) all at just over 3200 fps:
LC82; 60,500 psi
LC91; 56,200 psi
WCC91; 57,600 psi
LC00; 56,900 psi
Winchester White Box WCC07; 3351 fps at 65,700 psi
US M855
LC94; 3063 fps at 62,300 psi
Canadian M855 equivalent; 2948 fps at 60,000 psi
My M855 equivalent load;
Hornady 62 gr FMJBT, 26.5 gr Win 748 for 3038 fps at 57,000 psi
My M193 equivalent load;
M193 FMJBT/26.5 gr H335 for 3200 fps at 58,000 psi
My hunting/PD loads for gas guns (10 - 12" twist barrels)
Speer 52 gr HP, 26.5 gr H335 for 3160 fps at 52,000 psi
or 26 gr AA2230 for 3180 fps at 54.300 psi
My hunting/PD load for gas guns (7-9" twist barrels)
Sierra 55 gr Blitz King (the tipped bullet not the 55 gr SP "Blitz"), 26 gr H335 for 3200 fps at 57,200 psi
As we can see the psi of milspec M193 and M855 is above the SAAMI MAP for the 223 Remington. Note; both commercial and military arsenals do not load to the MAP levels, either SAAMI or milspec MAPs. They load, with a large lot of specified powder, to the specified velocity level +/- while staying under the pressure specifications. That is why we see a large spread of psi's from both commercial and military ammunition....simply different lots and/or even different types of powder used in the different lots.
Couple of the better articles on this subject
https://www.luckygunner.com/labs/5-56-vs-223/
https://ultimatereloader.com/2018/08...cts-and-myths/
Bottom line is don't shoot 64 grain tracers in a .223 chamber. Other than that it's a non-issue.
@ M-Tecs. Thanks for the links. I had not realized that the 5.56 chambers were designed to handle higher pressures. My current AR's have commercial chambers so I will not be using the 5.56 data. 23.5 grains of AA 2230 works well under a Hornady 62 gr. fmj boat tail and will be my utility round for casual shooting.
"I had not realized that the 5.56 chambers were designed to handle higher pressures."
No they are not.
The 5.56 chamber specs are simply for reliable function under the adverse conditions of dirt and fouling that a combat rifle may be subjected to. 55- 62,000 psi is the same whether in a 223 chamber or a 5.56 chamber. Neither chamber is "designed" to withstand more pressure than the other. It is the rifle actions that are "designed" to with stand the pressure. All modern gas guns, bolt actions and most SSs are designed to safely handle cartridges of 62,000 - 64,000+ psi. [Any action also chambered in the 308W or magnum cartridges, have the same psi level of MAPs or higher, will do just fine shooting 5.56.
The reason this topic comes up all the time is because of the assumptions, myths and opinions on sites like those on the internet. People keep reading those and since it is on the internet it must be right....right? Thus the "controversy" lives on. However, there is no real "controversy", just misinformation and opinions......
If you have a .223 Remington marked barrel with a 12" twist then M193 equivalent ammunition/loads can be fired in it all day long.....quite safely w/o any increase in pressure. You can also shoot M855 (62-64 gr "Green Tip") in it also. Yes, the pressure will probably be higher but it won't exceed the capability of any AR, bolt action or some SSs. However, accuracy will be dismal because the 12" twist won't stabilize the heavier, longer M855 bullet. That is all the difference. Back when the military transitioned from the M16A1 with 12" twist to the M16A2 with the 7" twist the manuals even stated that while it was safe to shoot M855 in the M16A1 not to do it because of inaccuracy. Unfortunately, many officers and NCOs failed to read the manual and most often said the reason was "higher pressure" of the M855 round. That was blatantly incorrect but the myth was started and passed along. I corrected many an NCO and office (mostly LTs) and suggested they read the FM. Doubt many did......
If you have a bolt action, gas gun or SS with the barrel marked 223 Remington with a 10" or faster twist then you can shoot both M193 and M855 equivalent ammunition and/or loads in it. The actions (and chambers) will handle the pressure just fine.
Of course many rifles factory rifles (custom rifles can be anything) have 223/5.56 on them these days. That signifies the barrels probably have a 9" or faster twist and thus is compatible with all commercial 223 Remington and milspec 5.56 ammunition. The chambers will probably be milspec if a gas gun and SAAMI Spec (because manufacturers adhere to SAAMI specs these days for liability reasons) if a bolt gun or SS.
If the gas gun barrel says 5.56 only then it too is compatible with 223 Remington and milspec M193 and M855 ammunition.
If the barrel just has 223 Remington on it then determine the twist by actually measuring it. Twists changed back and forth in many production models. If a 12" twist then use 223 Remington with 55 gr or lighter bullets and milspec M193 in it. You can shoot milspec M855 in it but, again, accuracy will be dismal or non-existent.
I have been shooting the 223/5.56 cartridge since the mid '60s in gas guns, bolt guns and SSs. I have got it straight from the horses mouth during those years when every change was made, why the change was made and what the use should really be. This was because of my military contacts and civilian contacts at the factories and arsenals. The laugh and scoff at the "internet experts". Several have told me basically, do they really think we (manufacturers) would make rifles chambered in 223 Rem or 5.56 NATO that were not safe with either ammunition in todays liability climate knowing full well many will use either ammunition in the rifles? But, they really like the controversy because it sells more rifles and much more ammunition.......
If you doubt this then go back to my previous post and look at the measured psi of the M855 and the equivalent M855 load. Both are normal for the cartridge. Both were fire in the Contender 21" barrel marked "223 Remington" with a very minimal SAAMI spec 223 chamber and throat. There was no excessive pressure, the rifle did not blow up, the sky did not fall and the world is still here...... That is fact, not opinion.
There is no difference in the pressure of either 223 or 5.56 chambers or what they were "designed for" regardless of the chamber specifications as it is the actions that are designed to contain the pressure......
Larry, does that apply to 7.62 & 308win, and the chamber differences are mainly to aid reliability under combat conditions?
Quote:
Originally Posted by Larry Gibson
YesQuote:
Originally Posted by zarrinvz24
Interestingly, chamber cast of my M16A1 with 12" twist milspec barrel chamber and the chamber cast of my Colt Comp H-Bar with barrel marked 5.56 NATO/1 in 9 show they are are essentially identical. The Colt lower is marked "223" as we're all Colt ARs back then before the internet controversy was dreamed up.
As an example the Western Powder reloading data using AA 2230 with the 62 gr. M855 bullet shows a max charge of 23.8 for the .223 and 25.3 for the 5.56. I can see why there is this controversy. So essentially the SAAMI specs are simply more conservative than the military specs. Many years ago I bought a 1000 rounds of delinked 5.56 ammo and that was the hottest ammo I ever fired in my ARs. Very sharp shot impulse and somewhat unpleasant to shoot because of it. Might not have noticed it as much in a bolt action rifle.