good article on .223 vs 5.56

[chances R]

http://www.gundigest.com/ammunition-reviews-articles/223-vs-5-56/4

[Dolomite_supafly]

This only confirms what I have been saying for a very, very long time.

Shooting 5.56 in a 223 chambered gun will not cause the gun to blow up or some other catastrophic failure. At worst a primer will come out of the case because of pressures. And considering that 25% of the rifles tested failed to meet 5.56 chamber dimensions means that there are a lot of rifles out there with a 223 chamber. And if shooting 5.56 was such a big issue we would certainly hear of 1 in 4 guns blowing up.

In the article there were guns that had "less than 223" dimensions and those guns did not dramatically fail when firing 5.56. It will cause a bit more wear and tear on your firearm. If your 223 firearm blows up when shooting 5.56 then your gun has some serious issues. Is it recommended to shoot 5.56 through a 223 chambered gun, no. But doing so from time to time will not cause the world to stop spinning or gravity to reverse like some people seem to imply. Pressure signs yes but no dramatic failure.

What they do not mention is by lengthing throat in the chamber you are going to see reduced velocities. And in todays world of the too short of barrels and too heavy of bullets you need all the velocity you can get. And the tool he recommends goes beyond even the loose 5.56 leade dimensions.

I do have a few issues with the article though. Implying that a warm barrel removes chrome any faster than normal is crazy. But even with that being said chrome is hardly the best option. As many of you have read Melonite treatment is hands down the best treatment for the longevity of the bore. It is way better than chrome lining.

To end, I have NEVER heard of a 223 chambered gun blowing up from shooting 5.56.

Dolomite

[DaveTN]

I question that any quality barrel makers are regrinding reamers, and if they are that they don’t know what they are doing or are not compensating for the regrind. Of course I have no idea as I have never been in a shop that makes barrels. But that’s just quality control; there are in tolerance or they are out.

[Dolomite_supafly]

I question that any quality barrel makers are regrinding reamers, and if they are that they don’t know what they are doing or are not compensating for the regrind. Of course I have no idea as I have never been in a shop that makes barrels. But that’s just quality control; there are in tolerance or they are out.

This.

Any barrel maker who has to regrind their reamers in order to make a profit are saving money at the wrong end.

Dolomite

[scoutfsu]

How much velocity are you giving up by having a chamber reamed to 5.56 or even fractionally beyond? SBR's have been killing people effectively for years. I don't think I understand your position on them. Where are you saying they're becoming ineffective?

And IMO, popped primers from too tight of a barrel are a pretty big deal. That typically means the pressure is far too high. What happens when you get some bullet setback? The combination could prove disastrous.

I wonder why he didn't name the brands with out of spec chambers? Maybe people like Pat Rogers have been on to something when they say certain brands are problem guns.

[Dolomite_supafly]

The difference between a .08" jump to the lands is ~100 fps. And the difference between 223 and 5.56 is larger than that. That is when you lengthen the bullet jump by that amount the pressures drop and in turn the velocity drops. And in the world of SBR's 100 fps is huge. If I had to have a gun with a 12.5 of shorter barrel it would NEVER be in 5.56.

It is readily accepted that a FMJ bullet will not fragment below 2,500 FPS, even if it tumbles. Tumbling helps the bullet fragment but only if the velocity is high enough. And the bullet will only tumble if the twist is slow enough.

Now take the average 10.5" gun shooting M855 and velocities are well below 2,500 fps in under 25 yards. A 12.5" gun will extend that to about 100 yards and a 14.5" gun will extend that to 200-250 yards. Because of this you need to rely on the bullet tumbling, even if it doesn't fragment, for it to be effective. Problem is in a 7 twist barrel the bullet will not tumble. So you wind up with a bullet that is too slow to fragment and too stabile to tumble. And this leaves 22lr type wound ballistics and yes a 22lr can kill, just not as fast as a bullet that is tumbling and fragmenting.

This is why we are hearing of all the problems with the current M4. They have shortened the barrel, increased the bullet weight and increased the twist. This is an attempt to make a short range cartridge into a long range cartridge and in the process ruined it. The shorter barrel reduces velocities which affects the bullet's fragmenting characteristics. The increased bullet weight also reduces the velocity. And when you combine those reduced velocities with a overstabilized bullet from the overly fast twist you end up with a bullet that just passes through the "soft" target.

Ideally if they wanted to improve the performance of the cartridge they would, at a minimum, slow the twist down. At least that way the bullet will at least tumble. But on top of that they would also need to reduce the bullet weight and thus increase the bullet velocities. These two things would improve the weapon so dramatically.

Here is a pretty good read on the subject.

http://stevespages.com/pdf/5_56mm_military_info.pdf

Dolomite

[scoutfsu]

Cool. Appreciate the read. What about the popped primers? That's a pretty big deal, especially on a duty/defense gun when it's locked up. It's a major sign of overpressure and the precursor for a catastrophic on you gun, no?

[Dolomite_supafly]

Popped primers can lock up the FCG, I have seen it. But guns who do see pressure like this do not fail catastrophically. Parts do break, like the locking lugs or cracks in the cam pin, but I have never heard of a catastrophic failure from a steady diet of 5.56 in a 223 chambered gun. I have seen guns run for hundreds of rounds after loosing a lug without an issue.

When an AR fails catastrophically it is because of bad reloads or squib loads. Not because 5.56 is fired in a 223 chamber.

Something else. On the other end of the spectrum. In the throats of "223" guns the majority have longer throats. It is probably because of the liability issues.

Dolomite

[kwe45919]

Great articles. As always, Dolo seems to have enough info to arm the great minds of us all......

[MiddTennTaco]

This only confirms what I have been saying for a very, very long time.

Shooting 5.56 in a 223 chambered gun will not cause the gun to blow up or some other catastrophic failure. At worst a primer will come out of the case because of pressures. And considering that 25% of the rifles tested failed to meet 5.56 chamber dimensions means that there are a lot of rifles out there with a 223 chamber. And if shooting 5.56 was such a big issue we would certainly hear of 1 in 4 guns blowing up.

In the article there were guns that had "less than 223" dimensions and those guns did not dramatically fail when firing 5.56. It will cause a bit more wear and tear on your firearm. If your 223 firearm blows up when shooting 5.56 then your gun has some serious issues. Is it recommended to shoot 5.56 through a 223 chambered gun, no. But doing so from time to time will not cause the world to stop spinning or gravity to reverse like some people seem to imply. Pressure signs yes but no dramatic failure.

What they do not mention is by lengthing throat in the chamber you are going to see reduced velocities. And in todays world of the too short of barrels and too heavy of bullets you need all the velocity you can get. And the tool he recommends goes beyond even the loose 5.56 leade dimensions.

I do have a few issues with the article though. Implying that a warm barrel removes chrome any faster than normal is crazy. But even with that being said chrome is hardly the best option. As many of you have read Melonite treatment is hands down the best treatment for the longevity of the bore. It is way better than chrome lining.

To end, I have NEVER heard of a 223 chambered gun blowing up from shooting 5.56.

Dolomite

Who else didn't read the article and looked at Dolomites response first? lol

[TMF]

I do have a few issues with the article though. Implying that a warm barrel removes chrome any faster than normal is crazy. But even with that being said chrome is hardly the best option.

Dolomite

I've always been under the assumption that MG barrels wear out their rifling faster from getting heated up and shot out. I always figured that applied to the rilfing in M4's being shot out quicker when burning rounds through it hot, like FA on a spendex.

[Dolomite_supafly]

I've always been under the assumption that MG barrels wear out their rifling faster from getting heated up and shot out. I always figured that applied to the rilfing in M4's being shot out quicker when burning rounds through it hot, like FA on a spendex.

A MG is going to see a lot more rounds and that is why they probably wear out quicker, not the heat. It is the blast at the case mouth that wears away the chrome lining at the throat not the heat. If it was the heat then the entire barrel would be relieved of its chrome lining and not just the throat. I am sure heat plays a part in it but I am also willing to bet that isn't the primary reason they wear out. Under extreme cases I am sure it is possible to blast the chrome from the bore but not with a DI AR because the gas tube will heat and burst long before the barrel gets that hot. I guess with a piston system it would be possible but that is a LOT of rounds on FA to get the barrel hot enough to loose ts chrome lining.

In the article he says rapid fire shooting hastens the chrome removal but I believe it is from the round count more so than the heat. That is why they military is trying to devise a way to count rounds for maintanence. If it was heat that ruined barrels all of them would be a lot bigger in diameter and have cooling fins. And when I get ready to build my "crew served" AR soon it will have large OD barrels with fins reminiscent of a Tommy Gun.

Look at the average round counts between a MG and a AR. The average MG probably fire 3x-4x more rounds than the average AR. That is why they wear out quicker.

I am talking about normal use conditions.

Not those times when the MG barrel is red, and nearly white, hot from firing. In those cases yeah heat probably does remove the chrome lining quicker but under "normal" firing rates I don't believe there is enough heat to remove the chrome from the bore any quicker. I have been on M60 ranges where the barrels were so hot you could see the bullet pass down the bore as it temporarily wicks the heat away from the barrel leaving a moving dark area that was visible from the outside. And in those cases there was a lot more sparks coming out of the muzzle than normal. This was no doubt part of the bore, the chrome lining as well as part of the bullet being vaporized. But that was with EXTREME firing rates, not normal firing tempos. So I will say that improper cleaning as well as the erosion of that blast at the throat removes the chrome more so than the heat.

Dolomite

[Dennis1209]

Personally, I kind a like my gravity, I'd hate to live without it.

I'm not going to press my luck by shooting anything in my .223 other than that.

I'll keep my feet grounded, why tempt fate and chance it?

What if gravity increased?

[TMF]

In the article he says rapid fire shooting hastens the chrome removal but I believe it is from the round count more so than the heat. That is why they military is trying to devise a way to count rounds for maintanence. If it was heat that ruined barrels all of them would be a lot bigger in diameter and have cooling fins. And when I get ready to build my "crew served" AR soon it will have large OD barrels with fins reminiscent of a Tommy Gun.

Dolomite

Well, I got egg on my face then. For years I had been the voice that prevented spendex's with M4's, since I was concerned about shooting out the barrels. I've seen it a lot on days where there ends up being a few cases more than what was needed, and we gotta dump the ammo so it gets used or face beatings. This results in folks loading up a bunch of mags and dumping on FA.... I'm not talking about one or two mags, I'm talking about a couple dozen. I've always prevented my guys from doing that 'cause I'm worried about heating it up and damaging the rifling, as I was taught. Guess I was wrong.

Right before I got out I started seeing the round counters on issued rifles. Thought it was pretty neat. I don't know if that is the new norm or not. I also don't know what kind of decision that drives, because they get inspected once yearly regardless. We had the sooper dooper heavy barrels, not the lightweight ones with the short life on them.

[scoutfsu]

SPENDEXes do and will damage/ruin barrels. That is a fact. Putting 1k of rounds through a barrel in a couple hours is drastically different than doing it in a year or months. Round counters are a benefit but so is taking note to the firing cycle of a barrel. It's not "this barrel has 10k through it, time to replace".... Gaging a barrel is an inexact science and a majority of 45B/reset people do it wrong. Even with the A1 barrels, you can and will burn them out....especially with the shooting packages SOCOM does.

I hate SPENDEXes for the waste of potential training. It disgusts me on a fiscal and shooter level. It's government bureaucracy at it's worst.

[TMF]

I hate SPENDEXes for the waste of potential training. It disgusts me on a fiscal and shooter level. It's government bureaucracy at it's worst.

I could write a book about how jacked up the budget system works. The irony that Fraud, Waste and Abuse investigations will leave no stone unturned after reports of office supplies being used for FRG purposes, but there is no emphasis on burning 1/2 mil in ammo just so we don't get screwed on the budget next year.

I didn't believe in it, and I wish I didn't have to be a part of it. At least on occassion I was able to drive around the back 40 and exchange ammo for brass to the units that actually needed it, which is of itself more illegal than if I just took all the ammo and spendex'd it myself, even though this ammo would go to another unit that is actually training.