.223 vs 5.56 mil-surp/spec in VEPR II

[mseanmc]

I just picked up my VEPR II .223. This thing is rock solid! I can't wait to get it out this weekend and put some rounds through it.

One question: Has anyone been firing 5.56 mil-surp or mil-spec ammo through this rifle?

I was looking at some great articles at http://www.ammo-oracle.com/#diff , and the SAAMI website. These sources warn against using the mil-spec/surp rounds in rifles chambered in .223 due to some slight dimensional differences.

What has been your experience with this issue?

Thanks,

[bigjross2002]

Im not sure but maybe a 5.56x45mm go-no go gauge would tell you if the chamber would allow it. If anyone else knows I would like to know if that is a possibility.

[chucku]

I have shot wolf .223, south african 5.56,lake city 5.56 and another kind of 5.56 out of my vepr II K with no problem. I have shot above ammo through my bushmaster without a problem either. I remember reading about something like this awhile back. I hope Im not doing anything wrong.:confused:

[bigjross2002]

Well acording to what I heard a rifle chambered in .223 is unsafe to fire 5.56 mm ammo. Now it is safe to fire .223 in a 5.56mm I here such as a Bushmaster. The 5.56 has higher chamber pressure than that of a .223 but im not sure exactly how high that is or if its unsafe in a VEPR. But I am kinda curious if it is or not. Robinson Armament would probably know.

[Mysterious]

Originally posted by bigjross2002
Well acording to what I heard a rifle chambered in .223 is unsafe to fire 5.56 mm ammo. Now it is safe to fire .223 in a 5.56mm I here such as a Bushmaster. The 5.56 has higher chamber pressure than that of a .223 but im not sure exactly how high that is or if its unsafe in a VEPR. But I am kinda curious if it is or not. Robinson Armament would probably know.

Roger that. A 5.56 weapon is good to go for .223 ammo - but the excess pressure of the 5.56 round (and thousands and thousands of product tests) is enough to have manufacturers issue legal disclaimers against firing 5.56 in a weapon chambered for .223.

I bow to their knowlege and caution... (I figure better to BOW NOW than try to DUCK LATER!) ;)

[Skibane]

I have *never* seen a post on this site that described a problem with shooting 5.56 ammo in a VEPR. Frankly, given the VEPR's robust RPK-style construction, it's not something that keeps me awake at night...

[bigjross2002]

Would my idea of a go no-go gauge idea work with finding out if its safe to fire 5.56x45mm in a VEPR. I would want to do it if I had one, just to be safe, as I like my face intact without a bolt carrier in it.

[HDR]

Half correct,

The cases are different and 223 is not as hot as 5,56.

You can fire 223 in 5,56, but its not reccomended to fire 5,56 in .223.

05/04/2001
.223 Rem VS 5.56mm

There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.

The cartridge casings for both calibers have basically the same length and exterior dimensions.
The 5.56 round, loaded to Military Specification, typically has higher velocity and chamber pressure than the .223 Rem.
The 5.56 cartridge case may have thicker walls, and a thicker head, for extra strength. This better contains the higher chamber pressure. However, a thicker case reduces powder capacity, which is of concern to the reloader.

The 5.56mm and .223 Rem chambers are nearly identical. The difference is in the "Leade". Leade is defined as the portion of the barrel directly in front of the chamber where the rifling has been conically removed to allow room for the seated bullet. It is also more commonly known as the throat. Leade in a .223 Rem chamber is usually .085". In a 5.56mm chamber the leade is typically .162", or almost twice as much as in the 223 Rem chamber.

You can fire .223 Rem cartridges in 5.56mm chambers with this longer leade, but you will generally have a slight loss in accuracy and velocity over firing the .223 round in the chamber with the shorter leade it was designed for.

Problems may occur when firing the higher-pressure 5.56mm cartridge in a .223 chamber with its much shorter leade. It is generally known that shortening the leade can dramatically increase chamber pressure. In some cases, this higher pressure could result in primer pocket gas leaks, blown cartridge case heads and gun functioning issues.

The 5.56mm military cartridge fired in a .223 Rem chamber is considered by SAAMI (Small Arm and Ammunition Manufacturers Institute) to be an unsafe ammunition combination.

Before buying either of these two types of ammunition, always check your gun to find what caliber it is chambered for, then buy the appropriate ammunition. Most 5.56mm rounds made have full metal jacket bullets. Performance bullets - soft points, hollow points, Ballistic Silvertips, etc. - are loaded in .223 Rem cartridges.

Firing a .223 Rem cartridge in a 5.56mm-chambered gun is safe and merely gives you slightly reduced velocity and accuracy.

However we do not recommend, nor does SAAMI recommend, firing a 5.56mm cartridge in a gun chambered for the .223 Rem as the shorter leade can cause pressure-related problems.

Winchester Law Enforcement Ammunition East Alton Illinois .

[FALPhil]

Originally posted by bigjross2002
Well acording to what I heard a rifle chambered in .223 is unsafe to fire 5.56 mm ammo. Now it is safe to fire .223 in a 5.56mm I here such as a Bushmaster. The 5.56 has higher chamber pressure than that of a .223 but im not sure exactly how high that is or if its unsafe in a VEPR. But I am kinda curious if it is or not. Robinson Armament would probably know.

You heard that because some @$$hole didn't know what he was talking about.

Some of the guys on this board need to sue their school districts for dereliction. The simple physics is this: all other things equal, if two different ammunitions produce the same average velocity, then the time-pressure curves are very similar. In other words, the mean high pressure is what produces velocity, and it is a linear relationship. What you want to be careful of is the absolute high pressure. You don't want it to exceed the safety factor built into the rifle. Fortunately, there is not much difference between military rifles and sporting rifles cover the safety factor quite well; the properties of the various grades of steel are well known and the safety factors engineered into modern firearms are in the ranges of multiples of anticipated high pressures. Since, for a given bullet weight, 223 Rem and 5.56x45 produce very similar velocites, their time-pressure curves and absolute high pressures are similar. Remember - we only have two types of propellants to choose from: single-base powder and double-base powder. It's not like we are packing C-4 in little brass cases.

Sure, there are nuances depending on case wall thickness, powder burn rate, etc. But none of that changes the physics of pressure and velocity. There are also differences in pressure-measuring methodologies which can confuse the issue if they are not understood. The so-called pressure differences between milspec ammo and commercial ammo is one of the biggest sacks of horse pucky that plagues our hobby. More people have passed up good deals on excellent ammo because of this. I suspect that it may be a combination of ignorance and/or unscrupulousness on the part of ammo peddlars, since the profit margin is higher on commercial ammo.

Pressure is easy to measure, especially today with inexpensive piezo sensors. It can be derived by knowing the burn rate of the powder and the velocity.

Winchester announcements notwithstanding, leade varies from manufacturer to manufacturer, model to model withing manufacturer, and rifle to rifle within model. So the Winchester argument is specious at best. theoretically, you could buy a commercial arm that has the same leade as the military chamber specification and know one would know it without measuring a chamber cast.

So, is it safe to shoot milspec 223 in a commercial 223 rifle? Well, let's put it this way: I know for a fact that the exact same ammo produces "higher" pressures when measured at Aberdeen Proving Grounds than it does when measured on modern piezo-electric sensors, which put the pressure extremely close to SAAMI maximums. I suspect that the reason is

[jram67]

roger that, I think its a bunch to do about nothing.

I've fired over 5,000 rounds of lake city 5.56 through my mini-14 (.223 chamber) and the sum bitch ain't blown up yet

[Otto Skorzeny]

Has anyone fired commercial stuff out of theirs? Doesn't commercial stuff have softer primers that might slam fire?