Hmmmm!!!!!!!!!!!!!!!!!!Thats a interesting note!!!!!!!!!!!!!!!!!!!!!!!

Dimitri

You happen to have any pressure data on the white box ammo? I've tried to find it but no luck.

I'd like to compare it to 223 pressure data.

Pressure data is the same as Military Spec M193 so it would be 52,000 PSI (using a 5.56x45mm NATO chamber with the long lead/bullet jump chamber) according to the US Army Ammunition manual I got.

Dimitri

Dimitri wrote:

Hold your horses, Winchester White box ammunition is repackaged 5.56mm NATO rounds (M193 rounds to be exact) Winchester makes if its Q3131 and if its Q3131A its Israeli military ammunition by IMI thats been repackaged!

I don't have the boxes any more, but I do recall vividly that it was labeled ".223 Rem" and a "USA" in a circle. It sported 55 grain fmj pills and the chrono averaged around 3162 fps on average. The bullet was a boat tail, had a cannelure, and the base had exposed lead.

The stuff with the LC headstamp was given to me by an EOD Spec 4 who had salvaged it at Aberdeen. It too had 55 grain fmj bullets, was marked "LC73" and "LC75" It was packaged on 10-rd stripper clips. The bullets were boat tails and had a cannelure, but these were fully copper jacketed with no exposed lead on the base. They chronoed about 3181 fps for an average, according to my records.

There were no signs of overpressure from the commercial or the military ammo.

chambered221 wrote:

It is possible to have two different loads that have the same velocity with pressures that are not even close to one another. Therefor yes, your findings on the chronogragh would be close to one another. But the chronogragh does not measure the pressure inside the chamber.

You are correct and I think I have acknowledged that, but in the case of 223 vs 5.56, I do not think that is the case. Otherwise, you would see signs of overpressure, which are just never present. Could it happen in a tight-chambered target gun? Sure. In an AR15 with a SAAMI chamber? Maybe. Probably not. In my CZ? Definitely not. There are enough numbnuts out there with ARs who never read gun forums who shoot the cheapest ammo they can find, probably milsurp, and they are not blowing up. Either there is plenty of safety margin, or this discussion is much ado about nothing.

Most 5.56 ammo that has been loaded in the Lake City plant has been loaded with WC844 which has very similar characteristics to H335. Both are available to reloaders and the velocities published by NATO are easily achievable with either powder without high pressure signs in most guns chambered in 223.

So, I am not going to worry about it. YMMV.

Phil,

I'll quote:

Quote::

Winchester "White Box" Confusion Q3131A Winchester "USA" brand ammo This has been making American shooters nuts for a number of years now... particularly in the immediate aftermath of 11 September 2001 when there was a major run on 5.56mm ammunition. Winchester's "generic" or "budget" USA, or "white box," brand of ammunition actually has two different 55-grain FMJ rounds, and one has to look closely at the "small print" to discern the difference. For openers, in addition to the ATK-operated Lake City plant2, Winchester is also a primary supplier of M193 to the U.S. military. That particular X223R1 round is commercially available in the white USA box product encoded "Q3131." What few realize is that Israeli Military Industries (IMI), the sole supplier of ammo to the Israeli Defense Force (IDF), also supplies their M193 as a subcontractor for Winchester; that round is often made available in the USA white boxes marked "Q3131A." By most reports, qualitatively, it is the same round and performs virtually the same as the home-grown variant.

www.thegunzone.com/556v223.html

Edit to Add: Mind you we can be talking about 2 different types of ammo Winchester makes, cause I do not know what Winchester sells exactly. I'm assuming their whitebox .223 is all the one and the same cause I only ever hear of the Q3131 stuff when White Box for AR's are mentioned. I buy Remington Ammo generally (never bought anything else).

Yup we may be talking about 2 different rounds, they sell .223Rem in 55gr FMJ as well listed as "USA223R1" ... its listed at 30fps slower then the Q3131 stuff. 3240fps vs the 3270 fps. Just saw it on their website.

Dimitri

Dimitri

Thanks you for the info.

52,000 psi puts it right around max pressure for a 223. [acording to data from Hodgdons powder]

I should have added; but forgot to. When using mil-spec 5.56 cases standard operating method says you need to reduce starting loads by 10 percent from the .223 data, and work from there. Again this is only for 5.56 cases not for .223 cases.

The difference in the Leade or if I remember sometimes called the"throat" right?, is also a big factor when it comes to pressure spikes. They build in this long throat to help reduce "chamber pressure" by the enlargement of the chamber when the bullet starts down the rifling. So your pressure is actually reduced over a longer travel distance so chamber pressure does go down but overall pressure stays fairly level. Part of the reason why larger bore handguns are sometimes easier to use than faster smaller caliber handguns. Less "felt" recoil.
They do this for the simple reason that not every country makes ammo "Just like the USA" Take for instance the ammo from Yugoslavia, very dirty and bore fouling. Russian ammo is not as dirty and does not foul as bad because they can make better powder so the pressure from a less fouled barrel is lower. Also different powders burn at different rates which creates the afore mentioned "pressure spike" and some are slower and take a bit longer to make peak pressure so again chamber pressure is reduced. Same thing for the metalurgy of different countries some make good brass like Lapua, some make crappy brass FNM. So in order to contain the pressure safely the case walls are thickened as this redueces internal capcity which when used with a faster burning powder will cause a higher "chamber" pressure and will as in the case with my Handi-Rifle stick 5.56 cases with .223 loads EVERYTIME! Bascially think of it like a delayed blow-back action or to those in the know a roller lock. The bolt starts back but is blocked by the rollers until the pressure is lowered and the unlocks, because if they didn't do it this way then another round in some type of auto-loader could be chambered and fired with much more pressure than the barrel could safely contain and kB!!! Big time! And remember also pressure is not always linear same with recoil. I would have to say that there are some folks here who seem to really know what they are talking about!!! That is a VERY good thing, because that makes ME think!

Now that I think about it... When loading for the AR, or other gas operated actions, you also need to keep in mind the pressure curve. There is an optimum pressure at the gas port for operating the system. Too high and its hard on the action, too low and it may not cycle. Obviously this wouldn't apply to manually operated actions. I'd read about this in some books on the AR.

Dimitri wrote:

www.thegunzone.com/556v223.html

Dimitri,

The Gun Zone is primarily Dean Spier. Dean belongs to that class of human beings known as "gun writers", which has been complained about in several threads on this site.

Don't get me wrong - I like most of Dean's stuff. He is a smart guy who has contributed greatly to the shooting community. But like all people who make a living at writing, he tends to zero in on the sensational stuff. So, I always look for corroborating evidence on anything I find on The Gun Zone website.

All good points. I would only add that I do not ever crimp .223 cases.

I would agree that .223 and 5.56 NATO rounds are not the same.
Take care...
Joe

jbird you still with us?????????????????


Joe Boleo Are you using a AR rifle with 30 rd mags?

Guys I know have had their bullets move in the mag when they didn't crimp them.

I am using 20 and 30 round mags and have never had a problem. Take care...
Joe

Phil,

True enough, sorry about all the fuss.

Dimitri

Hello again,
First of all thank you folks for answering my question. I am surprised I started a conversation on internal ballistics. I am excited you folks covered some things I was trying to wrap my brain around and perhaps help out others coming to this site in search of answers in the future.

I understood that the 5.56 had a longer lead time than .223 and that the average pressures where different. .223R app. 50,000 CUP and 5.56x45 app. 60,000 cup. Now We have a nice black and white explanation as to why. Also a reinforcement of this site which I stumbled on earlier. Gary Conways AR-15 page when I was searching for the operational pressures of the AR-15 gas system as to take to heart the warning in my Hornaday load book about exceeding the limits and causing premature failure of the receivers.

I have been sorting my fired cases into commercial and military groups with the unidentifiable ones destined to be weighed in comparison with the the heaviest of my military cases. I also have been told by a local (whom I am reluctant to just believe him with out verifying his claims) who worked for the Olin powder plant (Badger Army Ammunition Plant located about 25 min away from here and now being disassembled) that Lake City brass and Winchester Commercial (Which I have just purchased a large lot of new) are often the same wall thickness. Your conversation over Winchester ammo has put some merit in his claim. My scale and dial caliper will have to be my judge.

I am planning on building my loads on the heaviest of cases, recording the top of the average and then verifying functionality in the lightest of cases, recording the average as well. I then will have my brass lots sorted by average weight as to combat any major changes in pressure based on temperature (hotter temp = lighter cases and vice versa) . I am probably going to an extreme as these won't be "hot Loads" to begin with, but my guns are very important to me. (I was taught that a firearm is an extension of your body and your will. You obviously won't let a mall clerk perform open heart surgery on you will you.)

I will start with Varget (because I have a almost a whole pound that I tried in .30-.30 loads that did not pan out.) but I have a myriad of choices and all will be based on .223R loadings.

The current bullet choice is Bulk Win. 55gr FMJ that have to be sorted for wight and length consistencies as/ reports from the retailer of this bullet. Being is that it is a plinking round I am building I am not that excited over it.

I have just acquired a lee trimmer which I plan on chucking into a drill. I have to do a capability test on to see how close it trims. I normally use a Hornaday/pacific trimmer that trims the cases to an average of 0.0025" difference in length. If I can get close to this, I feel I should be OK in getting similar crimping pressures. Ideally, I would like 0.0000" without really knowing how it affects pressures. I would like to hear any ones observations on this matter.

jbird22cal wrote:

I will start with Varget (because I have a almost a whole pound that I tried in .30-.30 loads that did not pan out.) but I have a myriad of choices and all will be based on .223R loadings.

I am surprised that you didn't have any luck using Varget (or as we call it in Australia AR2208) for your 30.30WIN. I use it exclusively for my .243 and Mod 94 30.30 and find that it is very good for both calibres giving good accuracy.

A mate, and I, also use it to load .223 and find that it gives great accuracy with the Winchester 55gn bulk projectiles. The load we use for the .223 is .5gr under the maximum load and that works very well in three different rifles.

Cheers, Vince