24 December 2013, 17:04
RustyBrass vs Steel Cased Ammo- A Tourture Test
I ran across this article. Very involved lots of details.
Brass vs Steel cased ammo25 December 2013, 02:39
Samuel_HoggsonHowever detailed, the study design has a number of flaws. Barrels wear at different rates even using one type of ammo. This is b/c wear is not merely a function of contact materials. Barrel material base and gas bypass cutting (dimensional) are two variables not controlled in the study. This sort of study should have specified barrels from one mfg production line/batch (Bushmaster NY assembles ARs using bbls suppled from.......where?).
ROFs selected were arbitrary, IMO.
Even so, a good read. I don't have trouble believing steel jackets are more abrasive, but it would take a more rigorous effort to quantify this.
Moreover, the savings on ammo would have covered cost of an extra bbl for the steel exposed guns.
Sam
27 December 2013, 18:57
arkypeteRusty;
So as I read it the steel case does not make any difference. It's the copper clad steel jacket that causes the damage.
These torture tests are always a bit hokey since there's very few people who will shoot that many rounds that quickly.
Jim
28 December 2013, 05:54
HPMasterYeah, the steel jacket and harsh powders and rough priming compounds.....
That said, many of us are finding Tula primers to be the best on the market-bar none. (for consistent results across the chrono).
Steel cases and their coatings (lacquer and polymer) can cause issue though with extraction and chambering....
One photo and comment I take in question was the gas port sections, in all my experience, wear/cutting occurred prior to the port, not after the port.... and is attributed to gas and bullet heels/boattails.
Otheriwse I thought it rather useful in terms of ammo quality and barrel longevity.
28 December 2013, 20:14
Samuel_Hoggsonquote:
Originally posted by HPMaster:
That said, many of us are finding Tula primers to be the best on the market-bar none. (for consistent results across the chrono).
Steel cases and their coatings (lacquer and polymer) can cause issue though with extraction and chambering....
One photo and comment I take in question was the gas port sections, in all my experience, wear/cutting occurred prior to the port, not after the port.... and is attributed to gas and bullet heels/boattails.
Interesting take. I was taught that gas bypass cutting is responsible for most muzzle wear we measure with muzzle gauges in garands. This is due to port proximity. I can tell you the distal erosion in one of my 11.5" M-16 blasters is very obvious, as is the rifling wear at the muzzle close by. A magnifying glass demonstrates an appearance very much like that in the article pics.
In decades of use I have never seen one steel empty at a MG shoot showing evidence of lacquer melt. I don't believe it happens, or at least not to a degree that there is factual steel chamber on steel case contact. I deliberately let a live round cool in a chamber I had just tortured with 180 rds viaa FA mag dumps. It extracted easily and there was no lacquer melt. I repeated the test several times. Wouldn't you think I'd have seen something?
I think the slower obturation of steel results in gas/crud in the chamber. Maybe there are abrasive materials in the priming compounds/powders....dunno. The lower powered black box Wolf (non-ferrous projos) is worse in this regard than is the later Mil Classic/Barnaul/recent Tula stuff.
If there were factual significant chamber wear caused by steel contact any/all 5.56 chambers ought to become problematic in terms of extraction difficulties after prolonged steel case ammo use. Not so. Not one of my Colt uppers has even the slightest difficulty digesting steel. I have run the snot out of some of them. There are no pits, no abrasions visible on the chamber walls. This suggests there are finish or dimension issues with some chambers, and that crud builds there.
I have not used Wolf pistol/rifle primers, but have gone through about 15k Tula 209s. They are without a doubt the most consistent 209s I've ever used, insofar as velocity SDs are concerned.
Sam