[RobertArmiger]

This is something that is bugging me and may create a difference of opinions.I own an older Rem HBVS 223 rifle.I have on many occasions fired standard m193 ball ammo in this gun ,and have seen others,some very experienced shooters,do the same with seemingly no ill consequence.Am I doing something dangerous,or damaging with this gun?Any one else do this on a regular basis?

 

[aa1911]

I've fired a fair share of 5.56 through min-14's and AR's but it is generally frowned upon and considered unsafe.

 

[GunHugger]

It's done all the time. Should you? No. Can you? Yes.

Both use the same projectile (bullet).

It's the chamber dimensions that are different. The .223 freebore is shorter and jamming a full power 5.56 in there will spike chamber pressures in the .223 chamber.

Here's a Tech Note from Armalite on the subject;
TECHNICAL NOTE 74: 5.56 NATO vs SAAMI .223 REMINGTON
vs WYLDE CHAMBERS

 

[soundguy]

This is something that is bugging me and may create a difference of opinions.I own an older Rem HBVS 223 rifle.I have on many occasions fired standard m193 ball ammo in this gun ,and have seen others,some very experienced shooters,do the same with seemingly no ill consequence.Am I doing something dangerous,or damaging with this gun?Any one else do this on a regular basis?

223 in a 556 chamber is kosher.. but as the others stated.. 556 in a 223 chamber is lnot kosher. probably like shooting 'proof' loads in it..

 

[Jim K]

Well, no. The tight leade does not raise pressures significantly. What does is something not mentioned, which is the thicker brass of GI loads. Look at the picture above but further back, at the case neck. That neck must fit into the space for it in the chamber.

Now about the first thing that happens when the powder charge is ignited is that the high pressure gas forces itself into the case neck and expands it, leaving the bullet floating, for an instant, in a stream of gas*, held back by its own inertia.

Then the pressure builds and the bullet moves into the leade and into the rifling. At that point, the leade doesn't impose much impediment to the bullet; under that kind of pressure the bullet becomes almost plastic, like silly putty, and will conform itself to the shape of the leade and rifling.

But, if the chamber neck is too tight, or the case neck brass is too thick, the case neck cannot expand and pressures rise.** Both the chamber neck and the case neck are made with specifications, a figure of xxx +/- dimensions. So if a SAAMI chamber is cut by an old reamer and so is of minimal size, and the cartridge was made with brass of maximum thickness or with a case neck diameter of the maximum size, the case neck cannot expand and there can be trouble.

*It is that gas, flowing past the stationary bullet, that causes throat erosion, but that is another subject for another time.

**That is why the Germans, converting the old M1888 rifle to use the new ammunition with a larger bullet, needed only to expand the chamber neck; they didn't rebore or re-rifle the barrel.

Jim

 

[CCHolderinMaine]

Am I doing something dangerous,or damaging with this gun?

If the chamber is marked .223 only; then the answers to those questions might be yes, and yes.

The more experienced gunsmiths on the forum can probably tell you for sure based on you providing what actual gun you're using.

In general, as others have posted. 5.56 is a higher pressure round and cannot be safely used in a .223. It's fine the other way around. Just because the gun didn't blow up the FIRST time, doesn't mean it won't NEXT time.

 

[RobertArmiger]

I'm listening,I'm listening.Keep the coments coming in.The gun is a Rem 700 heavy barrel varmint special cal 223.Of course most on this forum know this firearm to be the equal of most any 5.56 or 223 cal gun in strength ever produced.If the 5.56 produces 10% greater pressure? than this gun should be acting not much unlike many other standard military arms.As for freebore or leade if it is less in 223, than that should create its own press increase regardless of the round.If you're talking about a perfect storm situation[higher initial pressure+less freebore]= dangerous pressure than that's not good.But is it really dangerous pressure?I know no manufacture wants to condone this for their reasons,but have others done this ,no problem?

 

[jedwil]

I'm listening,I'm listening.Keep the coments coming in.The gun is a Rem 700 heavy barrel varmint special cal 223.Of course most on this forum know this firearm to be the equal of most any 5.56 or 223 cal gun in strength ever produced.If the 5.56 produces 10% greater pressure? than this gun should be acting not much unlike many other standard military arms.As for freebore or leade if it is less in 223, than that should create its own press increase regardless of the round.If you're talking about a perfect storm situation[higher initial pressure+less freebore]= dangerous pressure than that's not good.But is it really dangerous pressure?I know no manufacture wants to condone this for their reasons,but have others done this ,no problem?

You should direct your question to Remington. Anyone that suggests deviating from the manufacturers recommendation would be giving bad advice.

 

[RobertArmiger]

Gunhugger et all,thanks. I think I concur with Armalite tech note #74"[ millions of nato rounds have been fired threw our saami 223 chambered rifles with no problems]".I first did this when I was shooting with a soldier who was in training at the Quantico Va sniper training school.We would bring our Rem 700s to a range in southern Maryland and he would bring m193 rounds left over from his school [hundreds of rounds ]that he claimed could be checked out, but not back in during practice.We would procede to shoot flies off our targets at 100 yds for fun.That was in the early 80's and I have put m193 ammo threw that gun ever after.No flattened primers,no sticky bolts,no apparent sign of excess.I think I will carry on with Armalite and my experience.