Gun Experts? 5,56 VS .223

[Traditional Farmer]

I've always thought that 5.56 NATO and .223 caliber were the same thing and have used both in my Ruger Mini 14,but today I bought a box of
5.56 62 grain bullets and it said on the box not to use them in guns that were labeled .223 so I shot a few and they worked fine.Whats the deal?
 

[Dauber]

The over all size is very close but the pressure is higher on a 5.56. You can shoot .223 in a 5.56 but not 5.56 in a .223.
 

[keh]

I think the military brass is a little thicker and may cause pressure problems. The 5.56 is loaded to higher pressures than the 223. The chamber specifications call for a greater distance between the chamber mouth and the point at which the bullet engages the rifling(called leade)in the military version than the .223. Since one principle of reloading for accuracy calls for the bullet to be seated out to barely touch the rifling, this may cause accuracy problems where there is a large gap. Present day makers of AR15 and Mini14 rifles try to engineer them to handle both types of ammunition. Don't know how effective that is. For your civilian .223 rifle, I would ask the manufacturer for advice on ammunition.I just reload my 223 ammunition using civilian brass and hopefull avoid problems.

KEH
 

[Scott 730]

Is your barrel stamped 5.56 or .223??
 

[FarmerZeb]

i agree with what KEH said

5.56 is around 62,000 units of pressure

.223 is a max pressure of around 55,000 units of pressure

(measuring pressures is highly technical and there are several different methods and many variables i give the numbers only for comparison purposes)

additionally the 5.56 chamber allows for greater variance cartridge sizing to allow for better inter-operability with in NATO countries.

the bottom line is they are not the same round they are governed by different standards organizations (.223 by SAAMI and 5.56 by NATO)


-Paul
US Army Ordnance Officer
 

[Mark6005]

Have been interested in a mini 14 for awhile but can"t seem to find one to check out at any local dealers. How do you like it? Seems its still reasonable to shoot and coyotes would be dandy targets. What would be a good price on one? Don"t know much about them but a guy that used to be a prison guard said they used them in the towers and he liked them
 

[BCnT]

i bought a secondhand mini 14 from my neighbors son...stainless and black poly furniture...shoots perfect...i gave $400. for this one.
 

[buickanddeere]

Mini 14 & M16 family is chambered and designed for the 5.56 and will accept .223
An off the shelf bolt action varmint rifle is chambered for the .223
 

[old]

556 and 223 are not the same. You can shoot the 223 in a 556 but not the other way around unless you want to slowly destroy the barrel of the 223 due to higher pressure which means a faster bullet etc
 

[buickanddeere]

Mini 14's vary in accuracy. Up until a few years ago when the factory re-worked the design and tooling for accuracy. Out of the box Mini 14's would barely hold a 3" group at 100 yards. A few would shoot around corners.
 

[MarkB_MI]

5.56 NATO is loaded to higher pressure than the SAAMI specs for .223 Remington. Not much to worry about with a bolt gun, but something to be concerned about with an autoloader. As far as I know all Mini-14s can safely shoot NATO spec ammo. Current production rifle specs say they are chambered in "5.56 NATO" so there's no question. I think some of older rifles were marked ".223", but were in fact intended to use either NATO or SAAMI spec ammo.
 

[old popper]

I saw a used Mini "ranch" in Scheels in Sioux City Iowa a little over a month ago, and they were asking $650 for it. I thought that was high, but several other gun dealers told me that wasn't a bad price.
 

[RN]

most of others give most of differences- note on leade, 5.56 NATO standard bullets are now longer and heavier- 62 grain or 70 grain- than original 52 and 55 grain so leade is about 2/3mm longer than .223 commercial chambering. Rifleman had article about 3 months back on chamber difference and the warning on pressure. A 5.56 Nato with the SS109/855 bullet will be interference touch of rifling in a new, tight .223 chamber-could be a pressure damage problem. Reloading surplus 5.56 cases with a 50/52 grain spire point for use in .223 chamber will be OK on leade/freebore- full lenght size case and check overall loaded length.RN
 

[Rich Iowa]

Like buickanddeere stated, the accuracy of the mini 14s varies. I may be wrong, but I believe serial #s 185XXX and up are the "new and improved" rifles. Ruger tightened specs and upgraded tooling, resulting in much better accuracy. I picked up an older mini 14 a few years back (turns out it was made third year of production and is older than me), reliable as heck but no tack driver by any stretch of the imagination. 50 yard shots averaged 3 1/2 inches, 100 yards opened up to 8 inch or larger groups. I have since added an Accu-Strut stabilizer and group size has been cut in half. Again, new rifles do better.
 

[BushogPapa]

You all seemed to miss the one item that effects accuracy with the 62 grain Bullet..
The 62 grain bulled requires a MUCH Faster Twist than a 55 grain, to stabilize it..
We are talking a 1 in 7" twist, for the Mil Spec Ammo..
55 Gr will shoot fine with a 1 in 10" twist..

Ron..