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223 Remington 5.56 Nato AR-15
Nubie
Member Posts: 4 ✭✭
Hello Everyone
I am new to this site and out of the firearm buying game for a while but have as of late looked back into it and reloading at the same time. Some years ago I picked up some AR-15 stuff but as some age and a child have come along my yearning for rapid fire fun is come and gone and I am more into same hole shooting from 100 to 300 yard range. I still like the AR-15 stuff I have but want to put more of a varmint kit together and was looking at some with a 1-9 twist Shaw barrel. I did do a search on here on the differences on the 223 versus the 5.56 barrel chamber comes in and as I understand it that if I get a barrel in 5.56 it will shoot both but if I get a barrel in 223 the extra pressure and leade would not be good to shoot 5.56 military stuff. (Please correct me if I am misunderstanding this) Since I am looking for accuracy will a 5.56 barrel not shoot 223 Remington in a good group? Also when reloading these two rounds do you use a small base dies for both chambers or just if I get a 223 Remington barrel.
Thank You
Chris
I am new to this site and out of the firearm buying game for a while but have as of late looked back into it and reloading at the same time. Some years ago I picked up some AR-15 stuff but as some age and a child have come along my yearning for rapid fire fun is come and gone and I am more into same hole shooting from 100 to 300 yard range. I still like the AR-15 stuff I have but want to put more of a varmint kit together and was looking at some with a 1-9 twist Shaw barrel. I did do a search on here on the differences on the 223 versus the 5.56 barrel chamber comes in and as I understand it that if I get a barrel in 5.56 it will shoot both but if I get a barrel in 223 the extra pressure and leade would not be good to shoot 5.56 military stuff. (Please correct me if I am misunderstanding this) Since I am looking for accuracy will a 5.56 barrel not shoot 223 Remington in a good group? Also when reloading these two rounds do you use a small base dies for both chambers or just if I get a 223 Remington barrel.
Thank You
Chris
Comments
And 5.56 in a 223 chamber, I never shoot factory loaded 5.56 in my 223s, but I do reload mil-spec brass for my 223s. I do always check trim length and neck thickness first though. No you are not misunderstanding the 5.56/223 differences. The 5.56 chamber is cut to looser tolerances to make up for heat/dirt/ and mass produced ammo. It is very common to find 5.56 brass long in OAL than 223 and the necks thicker also.
I have had no issue with a 5.56 chambered barrel producing good groups with 223 ammo, but this is with developed loads and not factory ammo so I am not saying YOU will or will not get good groups.
If you are wanting to just use 223 loads, I would look for a barreled upper that is factory chambered just for 223, they are out there I just don't know specifics.
Welcome back to all the fun and hope I could help a little![;)]
Oh, and Happy New Years![:D]
The shaw barrel that I can get comes cute in either the 223 Remington or the 5.56 nato round. The reason I was wondering was because a friend of mines brother had one he could never get to shoot reloads in even with small base dies because the chamber was too tight but maybe he had some other problems with it or a different cut in his chamber.
Anyway Thank You Again and Have A Great and Happy New Year
Chris
Welcome to the GB forums!
Your information is pretty close. The difference is that the 5.56mm throat is longer and a slightly different angle than the the .223 Rem.
5.56mm = 1' 30"
.223 Rem. = 3' 10"
This is what creates the potential for higher pressure. The short ogive varmint-style bullets normally loaded in the .223 Rem. don't reach the lands in the 5.56 chamber but the longer ogive 5.56 bullets get jammed into the lands of the .223 Rem. chamber. This jamming is what raises the pressure.
This is a brief explanation from The Gun Zone:
Almost a quarter of a century ago, SAAMI recognized potential problems with shooters assuming that the 5.56mm cartridge was identical to the commercially available .223 Remington round. Here is their 31 January 1979 release, with some minor errors corrected:
"With the appearance of full metal jacket military 5.56 ammunition on the commercial Market, it has come to the attention of the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) that the use of military 5.56mm ammunition in sporting rifles chambered for Caliber .223 Remington cartridges can lead to higher-than-normal chamber pressures and possible hazards for the firearm, its user and bystanders.
tests have confirmed that chamber pressures in a sporting rifle may be significantly higher in the same gun when using military 5.56mm ammunition rather than commercially loaded Caliber .223 Remington cartridges, according to SAAMI.
SAAMI points out that chambers for military rifles have a different throat configuration than chambers for sporting firearms which, together with the full metal jacket of the military projectile, may account for the higher pressures which result when military ammunition is fired in a sporting chamber.
SAAMI recommends that a firearm be fired only with the cartridge for which it is specifically chambered by the manufacturer."
http://www.thegunzone.com/556v223.html
"...but want to put more of a varmint kit together and was looking at some with a 1-9 twist Shaw barrel."
Do you mean a 'varmint kit' on the AR platform?
I don't see anything wrong with using a 1:9" twist barrel for accuracy shooting so long as you understand that it's the length of the bullet that determines what twist you need. In general, this twist will handle bullets up to about 70 grains. The problem we run into is that the manufacturers usually list bullet weight as opposed to bullet length. You need a formula (Greenhill formula) to figure out the relationship between length and twist also. There are some good Match bullets available in this range but the best Match bullets are in the heavier and therefore longer range of 75 grains to 90 grain requiring a much faster twist rate. Something to look into before deciding.
I am not a fan of Shaw barrels. There is a reason that they less expensive than the other manufacturers. Some of the members will claim they have gotten exceptional accuracy from these but they are truly the exception not the rule. I just got done borescoping 15 of these barrels and not one is worth using. I think you would better off saving your money for a bit longer and get a better barrel if you are really interested in getting accuracy from your shooting.
There's lots more to this accuracy shooting so if you have some time, read some more and ask more questions.
Best.
I am in the beginning stages of both here reloading and building a varmint kit on a ar platform.
As far as the AR kit I was looking at using a complete kit from some manufactures as I have a few ways to go about this from just getting a complete upper to a whole kit I will do some more research but I was leaning towards the 5.56 Nato because I do have some ammo put back and also still reloading for the same rifle. Some of what I have looked at have a wilson air-guaged barrel or shaw barrel from a 1-8 to a 1-14 twist barrel and every thing in between that come in complete kit. The others I would have to purchase separately and that maybe the way I will have to go. Could you or someone else point me to some good online sellers as well I will be going to a gun show here in indiana the indy 1500 witch I haven't been to in years to do some looking around.
As for reloading I am concerned with is this and I have taken the first steps to reading and learning with some help of a experienced reloader. I have the lyman and sierra reloading manuals already and the nosler reloading manual on the way. However what im not sure about is this in the sierra manual I have two sections for 223 one is the ar-15 and the other is bolt action but when I look at the two for differences as far as case and loaded specs on the round there is no difference in measurements there is just a difference in powder for which is the difference for cycling the ar-15 versus the bolt gun. If I am figuring this right I can probable guess but I would rather ask this and find out for sure. What I would have to do is measure the correct seating depth in the chamber to figure out how I should reload the round for each gun instead of just using the safe loaded oal and that would allow me to set up for 223 remington versus 5.56 nato. If I am wrong on this is there a set of dies I should be looking at specifically for each.
Thank You
Chris