I have been collecting a large supply of .223/5.56 brass from our agency range and wondered if there is any big difference between the two listed pieces of brass construction wise...
I know the brass marked with WCC 04 (NATO CROSS) came from cases marked Q3131. However, I noticed some other brass marked W C C 03, not sure where this came from package wise.
I noticed that on the Q3131 that the letters WCC are close together while the other brass is marked W C C, the letters are wider apart and lacks the nato cross.
As far as I understand, cases marked with the NATO cross are intended to indicated that the complete round is made to NATO Specs. Everthing from the brass construction, to the primer, powder, bullet, velocity, etc....
I have some LC Brass that doesn't have the NATO stamp and just has the date. Just because military brass like WCC or LC doesn't have the NATO stamp doesn't mean that it is not as good as the brass with the NATO stamp. Materially, it's the same brass. There will be differences with lots numbers and years of manufacturer of course.
I have not loaded WCC brass yet, but I haven't heard anything bad. It is mil-spec brass. I have 1000 rounds of WCC Q3269 with the NATO stamp on it. Although I will most likely never use that brass because the ammo is too valuable to shoot.
STANDARDIZATION MARKINGS and MEANINGS
In August 1959, the NATO Department of Military Standardization published the NATO identification marking. The NATO identification mark is a cross within a circle. All types of ammunition standardized by NATO and adhering to the terms of the Standardization Agreement (STANAG) bears this mark, indicating that the cartridge in question is interoperable with others so marked. However, it cannot be stressed enough that this marking alone does not guarantee interchangeability. That is to say, a random selection of 7.62mm NATO cartridges from different manufacturers bearing the cross-within-circle marking will likely display equally random ballistic performance. Only the inclusion of an additional marking on the cartridge packaging in the form of a maltese cross or four leafed clover indicates that the ammunition is expected to provide identical ballistic performance. If the clover symbol is framed, this is an indication that the accessories contained within the packaging such as clips or links also correspond to designs approved by the STANAG.
Based on the existence of these two distinct markings, it is evident that there are at least two types of NATO 7.62mm military ammunition. The first, bearing only the cross-in-circle marking, will function in all 7.62mm rifles and machineguns fielded by NATO armies, but may or may not provide the expected ballistic performance. The second, bearing both markings, will not only function in all arms, but will provide the ballistic performance prescribed in the STANAG (a 147 +/- 3 grain bullet with a muzzle velocity of 2,750 +/- 50 feet per second). The picture is muddied further for the US consumer of surplus 7.62mm NATO ammunition by the fact that many nations produced three types of military 7.62x51mm cartridges:
Those with cross-in-circle markings on the cartridges and cloverleaf markings on the packaging;
Those with only cross-in-circle markings on the cartridges
Those with NATO standardization markings
Consequently it is all but impossible for a buyer on the surplus market to know which standard, if any, the 7.62x51mm ammunition he or she has purchased adheres to.
Taken from: http://www.cruffler.com/trivia-June01.html
And as for .223 Rem/5.56 mm..........
.....NATO specification rounds (those marked with the NATO "cross in circle" mark) may have thicker cases and are thus able to withstand stretching better when fired in loose chambered military weapons (done for reliability purposes).
For re-loaders.........it all doesn't really matter what a headstamp says other then knowing that it is from a certain mfn. Most consider brass by headstamp, year.....and lot # if they have a record of it. Then, some will also weigh each case.
How much effort you want to put into it........is your decision.
WCC or W C C is GTG.
One more thing: if it was M193, there is still some ammo out there that won't have a NATO cross. Why? Because NATO never adopted M193. So you'll find LC brass, WCC brass, and all sorts of other stuff without a NATO cross on it, although it was loaded originally to military velocities. It it says "223 Rem" on the case head, it's highly likely to be a case with 223 Rem thickness and case capacity. Military thickness/capacity will probably have a set of letters and a year on it. Some might say "5.56x45mm".
It's just like the old surplus M855 from other nations. Only in the USA (maybe the Philippines too) does it have a green tip, since almost nobody else adopted the 55gr M193 cartridge.