Do you use 5.56 in a .223?

[R.H. Lee]

I'm about to purchase a .223 bolt action, probably the Savage Model 12 Varminter Low Profile, specifically to take advantage of the abundant 5.56 milsurp ammo availability. I'll of course save the brass, but don't plan to reload for this caliber, at least not in the near future. However, I've heard recent rumblings about the warnings not to use 5.56 ammo in .223 chambered firearms due to increased pressures (60,000 CUP vs. 50,000 CUP) and the differences in freebore or 'leade' which also may increase pressures.

I know several people who regularly use milsurp 5.56 in their Savages and Remingtons chambered for .223 and have not experienced any problems whatsoever; in fact the milsurp has been very reliable and accurate.

So I'd appreciate your experiences and opinions on this.

 

[gonzo_beyondo]

I'm about to purchase a .223 bolt action, probably the Savage Model 12 Varminter Low Profile, specifically to take advantage of the abundant 5.56 milsurp ammo availability.

Savage says it's a no-no.

People who use 5.56 in a .223 barrel are safe, IF it's an A2 chamber, like on the Mini-14.

 

[Bwana John]

My Bushy says .223/5.56 on the lower receiver, and I got no idea what the chamber actually is, so I guess I shoot both in both.

 

[AirForceShooter]

mini-14 here too.
If I can score some 5.56 from the base I'll shoo that otherwise Federal .223's
Both work

AFS

 

[Red Tornado]

I've got a Savage Model 12, but haven't shot any 5.56 in it. I'm not worried that it would cause problems, but I don't think it would give me the accuracy I desire from a varmint gun, and I bought it for accuracy.

From what I've read, here and elsewhere, it's not normally a problem in a bolt action. However, if I was trying to take advantage of surplus 5.56, I'd get a semi-auto, probably a Mini-14.
RT

 

[rbernie]

If you search on this topic, you'll find a few threads here where this has been hashed pretty well. My contributions to those threads usually went along the lines of, 'I've been doing it for about 20 years in various bolt guns without any issues at all. Maybe it's an issue for semi-auto chambers, but I believe that any reasonably modern bolt gun can easily handle the potential pressure increases from the differences in throat dimensions between the two chamberings."

 

[db_tanker]

My 12" TC shows no issues...albiet the accuracy isn't the same with my home-rolled rounds, but that is with about half the factory fodder I run through it.

IIRC, it was about 3 1/2" at 100 for that Izzy 5.56 that Winchester marketed. Then got ahold of some Brit SS-109 and was curious if the 12" bbl would digest it...shot into about 2" with no keyholes...

As has been said before, it depends on the chamber I am guessing...

D

 

[rocky]

With higher pressures, I would not risk it. Alot of the mil. surp. ammo from other countries is said to be less powerful than U.S. mil. ammo. Maybe check out the ammo -oracle?

http://www.ammo-oracle.com/

 

[EghtySx]

http://www.ammo-oracle.com/body.htm

 

[Kramer Krazy]

I have a Ruger M77 MkII heavy barrel that has only seen about 200 rounds, so far. All those rounds have been 1992-94 Winchester factory loaded labeled "5.56" on the box. This is the only ammo I've fired through it, but plan on buying actual .223 spec ammo for it in the future. I don't plan on ever shooting any mil-spec surplus through this gun. I save the surplus for our three AR-15s chambers in 5.56.

 

[R.H. Lee]

The consensus with everybody I know who shoots 5.56 in a .223 is that's it's ok. Twist rate and accuracy seem to be the issue; most commercial production bolts in .223 apparently have a 1:12 which is barely enough to stabilize the 55 gr and no good at all for the 62 gr. The Savage I want is 1:9 which should be good for both. It's moot however; this rifle is essentially unvailable and on back order until at least Spring.

 

[rbernie]

most commercial production bolts in .223 apparently have a 1:12 which is barely enough to stabilize the 55 gr and no good at all for the 62 gr.

Bullet stabilization is driven by bullet velocity and bullet contruction and bullet length and not by bullet weight. It's just that bullet weight is a handy (if not quite correct) way of corrolating things.

The concern over 1:12" being insufficient for 55gr and up fodder is largely misplaced. For example, my Weatherby Vanguard in 223 with a 24" barrel (good for velocity) would shoot 62gr and 65gr stuff just fine. My 16" 1:12" AR (modified SP1 upper) would not - it just couldn't get the bullet moving fast enough in the shorter tube to spin it up reliably. But the point is simple - it's not the weight that's the issue, it's the bullet length and velocity that's largely at work.

As a general rule, I wouldn't count on anything more than 62gr stabilizing in a 1:12" twist if the barrel is shorter than 20". If you have a 16" barrel, go for 1:9" or 1:7". If you have a 20" to 24" barrel, 1:9" is a good all-around choice. But if you have a 24" barrel with a 1:12" twist, you can often get away with running bullets below 65gr just fine. Of course, a 24" barrel with a 1:9 twist is probably the most versatile choice.

 

[Magnuumpwr]

I own a Savage 12FV with a 26" bull barrel and a 1 in 9" twist rate. The most accurate ammo I have found are IMI 62gr AP sold in the 30rd brown boxes. The IMI ammo is mil. surp. 5.56, with the Nato headstamp. Never had a failure to feed, fire, or extract. For cheap plinking ammo I use Wolff 62gr FMJ's. Trajectory is very close between the 62gr loads. Not to seem one sided, I have also shot a variety of domesticly produced ammo from 45gr to 75gr and numerous grs in between with no impressive grouping. Also I own a Bushy ar-15 rifle, 16" barrel with a 1 in 9"; a Bushy ar-15 pistol, 7.5" barrel with a 1 in 9"; and a Ruger Mini-14 ranch rifle, not sure of barrel length or twist. About the only ammo I shoot in all 3 semi's are 55gr, 5.56 mil. surp. and have yet to have any problems to date.

 

[possum]

In a bushmaster they will accept either rd. that is he most experience i have with .223/5.56 The main difference in the rds are the chamber pressure that is created when the rd is fired. .223 is normally 42,000 psi and the 5.56 is about 52,000 psi. Not all manufactures aprove of using 5.56, but the ones that do, made it possible by having better, and stronger recievers and other parts. that can take the extra pressures. i put 5.56 and only 5.56 through my bushmaster, and never had a single issue. The case walls of the 5.56 are also a little thicker. I am pretty sure that almost all big time ar and assault rifle makers, have a quality product and shooting the 5.56 will be no problem!

 

[thatguy]

It's my understanding that mil-spec 7.62 and 5.56 ammo have a slightly different shoulder contour to compensate for the ammo being slammed through a full-auto weapon. Some manufacturers caution against using military ammo in their sporting rifles but I think they do this on advice of counsel. I have used mil-spec 5.56 in my SP1 AR15 without any problems for 25 years, now, and have also used it in an Interarms Mini-Mauser .223 without a hitch for 10 years.

I have also had zero trouble with mil-spec 7.62 in a Belgian FAL, an HK91 and a Ruger M77 in .308 Winchester. I have heard some shooters say that the bolt may be hard to close with some military ammo in the bolt guns due to this difference in the shoulder specs but I have not noted this in my experience.

 

[trickyasafox]

i've used LC brass, but never pre-loaded 5.56, its just not as readily available by me.

i'd use it though

 

[TexasRifleman]

I have also had zero trouble with mil-spec 7.62 in a Belgian FAL, an HK91 and a Ruger M77 in .308 Winchester. I have heard some shooters say that the bolt may be hard to close with some military ammo in the bolt guns due to this difference in the shoulder specs but I have not noted this in my experience.

7.62 and .308 are identical, so there is no problem there.

 

[Sleeping Dog]

No trouble with 5.56 or .223 in my Rock River upper with 1:8"-twist stainless barrel. It has a "Wylde" chamber, whatever that is. I've heard it's a tighter chamber than military, but looser than match.

Regards.

 

[JohnKSa]

I think we can safely discount the single poll response that said they had problems.

Clearly that responder can't read or they would have listed the problems they had as requested. The way I see it, that means that it is entirely reasonable to assume that they misread the responses and accidentally checked the wrong one.

Ok, nobody get wound up, I'm not suggesting that anyone ignore SAAMI or a firearm or ammo manufacturer. Just ranting a bit about people who can't follow SIMPLE instructions...

BTW, on a separate but related note, I agree with rbernie. 1:12 twist will usually stabilize 62gr bullets of typical construction. In fact, Berger Bullet's website recommends 1:12 twist for .224 bullets up to 64 grains. However, these are standard lead jacketed bullets. If you have a solid copper projectile or a bullet with a steel penetrator core, that increases the length for a given weight and therefore also increases the twist required to stabilize it properly.

 

[f4t9r]

shoot both in my AR NEVER A PROB

 

[Bartholomew Roberts]

I have never seen major safety issues firing 5.56mm in a .223 chamber - it does create popped primers and function issues if you fire 5.56mm out of a AR15 chambered for .223 SAAMI. This is basically a gas system issue.

I haven't fired 5.56mm out of a .223 chambered bolt gun, so I can't comment there.

A Wylde chamber is a good compromise for better accuracy without sacrificing reliability and does allow you to use 5.56mm ammo.

 

[rangerruck]

it has to do with mil specs versus saami specs, the mil stuff is a little hotter, case thicker, etc. but if you are shooting a bolt action, no worries. that being siad, i have not found any mil spec ammo that groups well in my rifle, my cz is a 1/12 twist. your basic mil stuff is 62 grain so you deed a 1/10 twist or faster. so if youdo get a bolt gun, make sure the bbl is like 1/10 or 9 or 8. that wya you can shoot the heavier stuff.

 

[asknight]

I shoot 5.56 and .223 in both my 700 and my Mini-14. Olympic, XM193PD, Q3131, and countless others work just fine in both rifles for plinking accuracy. I've settled on handloading for most of my shooting as a 40gr VMAX worked best for me in the 700 with 1-12", and 60gr VMAX in the Mini-14 with 1-9". I have to blast up the 5.56 to get the brass to handload

The only trouble I've had in my boltie was trying to run Wolf (both 55 and 62gr) through it. A bit harder than usual to close the bolt on, and even harder to open the bolt after firing.

 

[Optical Serenity]

I've shot .223 in my Rock River AR-15 that is marked 5.56 without any problems.

 

[Wilburs Horse]

The consensus with everybody I know who shoots 5.56 in a .223 is that's it's ok. Twist rate and accuracy seem to be the issue; most commercial production bolts in .223 apparently have a 1:12 which is barely enough to stabilize the 55 gr and no good at all for the 62 gr. The Savage I want is 1:9 which should be good for both. It's moot however; this rifle is essentially unvailable and on back order until at least Spring.

You can overspin stubby bullets. Most Rem. 700s in .223 are exceedingly accurate so I been lead to believe. Anyone know what twist Rem. uses in 700s?