Newbie Questions regarding .223 reloading using 5.56 Case

[FunShot]

I just started reloading barely a month now. I'm into .223 shooting with my brand new rig and wanted to get the best accuracy out of it with locally available components. Sadly from where i come from, only 5.56 local uncrimped ARMSCOR brass is readily available. I do have premium lapua brass but i only use them for target shooting considering it's really hard and expensive to have them imported here. Cost is over $1 for lapua brass and over or equal to about $1/2 for regular U.S. brass like hornady or winchester, and that's per piece. I did a bit of research and found out that when using 5.56 brass for .223 bolts, one should take into condition the thicker walls and use less powder to achieve equal pressures or velocity. Problem is, i currently don't own a chronograph so i can't experiment with my loads and the nearest fella i know with a chrono near my place is about an 8hr drive away and the chrono i ordered would probably arrive here in about 2mos given the remoteness of my location. I was hoping if anyone here has any suggestions on how i could at least get a setup going to replicate my current loads with .223 brass. My current setup is using 52gr Sierra MK BTHP with 23gr Vit n133 powder. How many grains of powder should i use to at least get a safe equivalent in the 5.56 brass? ???

 

[jonbearman]

Where are you from?

 

[jonbearman]

Using the military brass,back off 10 percent and work up. What kind of rifle is this,that may make a difference altogether.

 

[FunShot]

I already did the -10% and work up but i still can't experiment since i don't have a chrono yet. Anyways, i'm in the mountains on mindanao, philippines managing the family ranch. My rig is a ruger 77 hawkeye tactical, all with factory parts.

 

[Shynloco]

FunShot,
Just read your post and I wasn't quite sure what weapon you are loading for. But in your last line, it appears you are loading for a Ruger Hawkeye bolt gun. And that leads me to your brass. If I recall correctly, the rule of thumb is you can use .223 Brass in 5.56 cal weapon (Semi-Auto), but it is recommended NOT to use 5.56 brass in a .223 Caliber weapon, particularly a bolt gun. I cannot tell you the reason why other than there is a different in the brass and throat differences in the weapons. Now I'm NO expert in this, but I have never tried using the 5.56 brass in my Savage Model 12 VLP and never plan on it. The reason, the warnings I've seen plus that Lapua .223 brass using 24.6 gr of VVN133 and Federal Match Primers, put together really tight groups using Sierra 52 gr HPBT, 53 gr HP Match and particularly 55 gr Blitzkings @100 yds. I have never chronied any of these combos and have no plans to buy a chrony. The proof of finding out what works best in YOUR PARTICULAR weapon is target scoring plus trial and error. I think you might be about 1.5 gr low on your rifle (when loading with VVN133) as far as accuracy, but is a good starting point. Good luck and if you are having problems getting your hands on some .223 brass, give a hollar and I'm sure a "Care Package" can be arranged containing Lapua or whatever brand you believe you can use.

 

[Kenny474]

There is no issue with using 5.56 brass, it is however an issue to use 5.56 loaded ammo in a rifle chambered to .223, as the throat is too short in the .223 and the 5.56 is loaded to a higher pressure, hence the thicker brass.

As long as you reduce your loads just a bit, 5.56 brass is fine. It just has a bit less capacity. I have been using reformed LC 5.56 brass in my .222 when plinking or varminting since I built it, with no ill effects and great accuracy.

One way to figure out how much to reduce the loads from the .223 brass, is to take a volume measurement of the .223 brass using distilled water (basically weigh the empty case, and then weigh it full of water) and compare it to the 5.56. Now figure out the percentage of reduction in case capacity from the .223 to 5.56, and reduce your powder charge (of an accurate load developed in .223 brass) by the same percentage. I am not 100% positive it will get you spot on, but it should be close.

Basically, if you have 96% of the .223 capacity in the 5.56 brass, use 96% of the charge weight in the 5.56 brass as you normally would in the .223. I have done this with my .222 with good results. But do not do this if your load is very close to a max load in the .223. You will need to reduce it a bit further to be safe, and then work back up.

You don't need a chronograph to develop a good load, just go by how accurate it is. Velocity means little unless the load is accurate.

Just start with the figure you get from the above calculations(reducing slightly more if you are close to max), and adjust until best accuracy is achieved.

Forget about velocity, and just go by accuracy.

 

[Shynloco]

Thx Kenny474,
Looks like at least I got part of it right. I guess I didn't get the part about "loaded" quite right, but it is good to know the reason which I kinda suspected. And I agree not to worry about velocity when accuracy is the issue. I all my years of shooting weapons (50+) and a lot less of reloading time (2 yrs), I have never Chronied any rounds and have some very excellent accuracy with developing loads for various different rifles I own and shoot regularly. Thx again for the clarifcation issue on the 5.56 brass.
Alex

 

[Shynloco]

Hey FunSHot,
Based on what Kenny474 explained, 96% of my previous recommended load when you are using 5.56 brass, comes out to 23.6 for your load. So increase your load by .6 gr and see how she does. You should gain some accuracy. BTW, I failed to mention the Ojive measurement I use on my loads is 2.970 which is a bit longer and places the bullet a bit closer to the lands and grooves than the standard OAL measurement listed in the Sierra Manual.

 

[Rtheurer]

Hi Funshot
I would hate to guess what a more exotic case would cost like the expesive 6.5X284 case would be where your at? Whooo Doggy.

I keep hearing the comment of 5.56mm brass being thicker than commercial 223 brass. Where does this keep comming from? There is a good article right here on this sight that dispells that myth ( Myth Buster? ) If you find the thread you will note that somewhat recent production Military brass IMI Lake City PMP vs Winchester Remington, Lapua are very close in INTERNAL case volume. In fact some Comercial brass actually has LESS capacity than our LC or IMI brass.
I read an Article not to long ago in a Major magazine stating this same thing? The Thick Brass from the 7.62 to 308 is not the same as 5.56 to 223 yet for some reason this keeps getting spread around and now for some reason is truth dispite proven wrong.

Kenny nailed it by having you measure the internal Capacity. Then you will Know.
Best of Luck
RussT

 

[necchi]

I think the "Myth" exists for good reason. Not all mil brass is created equal. And while current LC 223 NATO may have a higher capacity than some civie stuff the topic is 5.56 brass, a different creature. Your right, on this forum is the list of 223 capacity;
(note: This is Not 5.56)

Lake City 06 - 30.6
WCC99 - 30.5
Sellier & Belloit - 30.5
Remington - 30.4
PMC - 30.4
Hirtenberger - 30.4
Lake City 04 - 30.4
Federal - 30.2
Hornady - 30.1
IMG (Guatemalan) - 30.1
Lapua (new lot) - 30.1
Winchester - 30.1
Olympic - 30.0
Radway Arsenal - 30.0
PMP - 29.9
FNM 93-1 - 29.8
Lapua (old lot) - 28.0

This list in and of it's self is enough to show a significant differance. Heck, I'm still seeing LC Nato 96 brass on a regular basis? It's not on this list?

Best advice here has been to just back off a bit and re-work for accuracy. If your lucky you'll find a good load with less powder. ;D

 

[FunShot]

Tnx for all the info. Will try out my test loads for accuracy when i get the chance. The reason i wanted a chrono is just to get the same velocity as my current rig since i think my current setup is what is best suited for my gun. Again, thanks. I might just see what particular load has the same point of impact at 100meters and just assume that the velocity is about equal.

 

[Rtheurer]

This is true that you should always reduce your load from someones personal pet load. Like everyone here I would hate for someone to get out there and blow up a gun because they Thought it would be safe.
But Im still going to stand by my statement that its a myth that ALL mil brass is thicker than the Comercial brass. Like mentioned not all brass is created equel in this sense.

Again good luck in your search.
Russ T