[jor-el]

http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/#bookmark4

In a nutshell, four Bushmaster MOE carbines were used to test four brands of .223 Remington. Each brand was fired in a particular rifle to determine rates of malfunction and wear. 10,000 rounds were fired per brand, presumably over a single day in Arizona.

Federal American Eagle 55 grain. The control brand using brass cases and gilding metal jacket bullets.

Brown Bear 55 grain. Laquered steel cases and bi-metal jacketed bullets.

Wolf WPA MC 55 grain. Polymer coated steel cases and bi-metal bullets.

Tulammo 55 grain. Poly cases and bi-metal bullets much like the Wolf.

I'll cut to the chase and point out Brown Bear and Wolf caused substantial performance issues vis a vis accuracy and reliability. Tula had other issues that prevented it from completing the 10000 round test. The bi-metal jacketed ammo did produce substantial wear and tear on the rifles. Moreover, the muzzles of both BB and Wolf had zero rifling.

Federal? That rifle had wear and tear as expected from firing 10,000 rounds, but it retained acceptable accuracy ( because it didn't grind out the rifling) and had 0 malfunctions.

Now, the Minis we own are unlikely to be utilized like that. Still, Minis aren't chrome lined, with spare parts available over the counter either.

Thoughts?

 

[tri70]

I agree that the brass is the best choice for all semi autos. Steel shot thru them intermittently won't wear them down as fast. As far as the mini series, they have a long throat before rifling is engaged so they may handle steel better. The design and gas system is simple and durable and would be great see how it would hold up, the minis don't break down very often.

 

[curt mini14]

if you mag dump any ammo and get your barrel hot enough to melt like that what did you expect to happen.any ammo will do that.

 

[MDsonofthesouth]

Well at the rate of ammo shortages it will take 100 years to shoot that much. Am I worried about my mini? Hell no the things a champ.

 

[Marlin 45 carbine]

chrome lined is the magic word. the russkis did this both to increase wear resistance
effect of the commonly corro-primed military ammo.
dumping mags defintely increases rate of wear as curt pointed out.

 

[Tommygunner]

One of the reasons i started reloading for my Mini is because of the steel jacketed bullets. IDN if any of you guys have ever taken a file to the bullet on Wolf, Tula ect. But the copper coating over the steel jacket is very very thin. It is just a copper electroplate film thinner than a human hair. The reason they copper coat it is to keep the bullet from rusting it does not protect your bore very much. The rifling will easy wear thru and penetrate the copper down to the steel jacket as the bullet passes down the barrel. That is why the muzzles were wore out on those test guns. The copper wore off as the bullet passed down the barrel and the steel did its job on the muzzle.
I really dont think steel is good for minis espically older ones that have a 308 bore. The manual that came with my old mini stated in it. Not to use imported ammo because it will cause damage to the gun. I know the newer minis were redesigned to use imported ammo. But still. Shooting steel will eventually wear the bore in a non chrome lined gun.
If you think shooting steel is Ok.
All I have to say is this. Would you clean your gun with a steel bore brush?
If those bullets you are shooting were bright and shiny steel. Instead of spray panted with copper to look good and keep them from rusting. Would you put them down your gun?
Go grab a cheapo wolf Tula or other imported russian bullet and put a file or sand paper to it. You will see what i mean. It will sure give you something to think about the next time you go to the range.

 

[jgodwin2]

Handy magnet would tell the tale.

 

[hottarod]

Copper coated lead fmj is the same regardless of whether it is loaded in a brass case or a steel case. I'm sure that all the bullets were copper coated lead so the difference in barrel bore wear was something else.

The difference was most likely because the Ruskie ammo shoots a lot dirtier than the Federal. The Russian powder might also shoot hotter. All that carbon build up in the barrel without cleaning is like shooting through carbonized sand paper and will hone the barrel out. If you get the barrel hot enough it can also get up close to heat treatment territory which would also accelerate wear on the barrel. They should have taken temp measurements of the barrels during this test.

It is possible that the steel cases might be harder on a gun's chamber but I think it is just the opposite actually. Steel cases may expand less than the brass when fired so there is less wear on the chamber as each spent casing is extracted. To know for sure I would have to mic a spent brass versus steel case to see what the difference is and i have not done that.

 

[TxQuail]

Russian ammo is steel covered lead! It has a copper wash on it.

Russia uses steel jackets and steel cases

 

[Tailgunner]

The steel used to make bullet jackets is not only softer, but one heck of a lot softer, than the barrel steel.

Perhaps you don't know it, but the US military ordered, acquired, and used over a BILLION (yes, with a B) rounds of ammo loaded with steel jacketed bullets in WW-2. Enough so that they ended the contract early, as they realized that just one plant had produced MORE ammo than they could use even if the war lasted another 3 years.

10,000 rounds through one rifle in one day? 16.67 rounds/minute for 10 hours, or 20.8 round/minute for 8 hours (and no potty breaks).
Who was the iron thumbed guy that was stuffing mags? He's the real hero, loading 1,333 mags in one day.
The idiots doing this "test" are morons. They didn't even attempt to control any of the other variables (Hint, barrel wear is NOT from bullet passage)

 

[mini5277]

I have read about a test like that but cannot remember the specifics that were mentioned about barrel wear.They maybe referring to chamber wear/head space.
Steel against steel in a critically tolerance area is never a good thing.

 

[hottarod]

Well I learned something new. I didn't think these rounds were steel jackets but they do have a thin metal jacket that is coated with copper. However, they do not look like the old WW2 steel jackets that my brother and I found and shot. The metal on those was a lot thicker than these rounds but it is still steel or what the scrap yard calls tin(soft thin metal).

I looked at a tula fmj more closely. I can crimp it fairly easily with my pliers so the metal is not very tough but tougher than copper I would suppose.

I also think I may see a reason why these rounds do not fly as precisely as they could. On the back end where the metal jacket quits is a lip and the lead core is recessed down in there and left exposed. It is not completely flat either. This can't be good for ballistics.

 

[Tommygunner]

I am glad you took the time to disect a tula round and see what kind of crap you are shooting. Yes they do use soft steel but it is steel nun the less, its harder than copper and it will wear the barrel. As I said the copper coating is only there to prevent rust not to prevent barel wear.
Do i shoot russian ammo? hell yes its (was) cheap. I have Ks rounds of tula ect, for my russian guns SKS, AK, I do shoot them in my Mini once in a while but i dont like to. They dont shoot straight. My reloads are sooo much better.
I dont think you will ruin a mini by shooting steel jacketed bullets but you sure aint doing it any good either.
Everytime that bullet goes down the bore you are ripping a little steel off it. That steel stays in the bore /rifleing and causes more and more wear as you continue shooting. Heat can also temper the steel particles and make them harder. Regular cleaning will help a lot. But how many of you clean your guns after 20 rounds or so?

 

[grumpy_old_man]

I also think I may see a reason why these rounds do not fly as precisely as they could. On the back end where the metal jacket quits is a lip and the lead core is recessed down in there and left exposed. It is not completely flat either. This can't be good for ballistics.

Hi hottarod;

That's exactly the reason for the OTM (Open Tip Match) ammo, and why its not classified as a "hollow point" for legalistic reasons of issuance to US forces. The flat base makes it more accurate and the open tip is just a side effect of manufacturing the base. Pity if it tears the target inside out when it opens up....

Best,
Grumpy

 

[hottarod]

Examples;
polymer tip, crimped, flat base, full copper jacket(Hornady z-max). These look like they should be a lot more consistent than the second photo although they are not a boat tail design. The BC is .295 on these.

copper washed steel jackets, no crimp, indented pocket with inconsistent surface exposing the lead core at the back, fmj or hollow point, brass coated steel case or lacquer coated steel case. you can see the indent better if you blow up the photo. I think the BC on these is something over .300 and as much as .330 or .360.

Hornady SST for 7.62, polymer tip, copper jacket, crimp(cannelure?), boat tail, BC is .295

 

[grumpy_old_man]

Hi Hottarod;

You know, you're bringing back some old memories - I believe the first boat tail bullets were notorious for excessive throat erosion back during WWI. IIRC the first generation of Mark VIII Z .303 for the Vickers gun had a combination of a hot nitrocellulose powder and a poorly sealing bullet that was the culprit.

Makes me wonder if those harder than normal steel jackets aren't sealing properly in US spec rifling? Gas blow-by combined with high temps from mag dumps and the Russian powder could combine synergistically to burn the lands from the bores in that video. Sort of like how smoking is bad and radon is bad but smoking in a radon filled environment is worse than just adding the two cancer risks together.

Just some thoughts.
All the best,
Grumpy

 

[hottarod]

I believe that explains the problem yup.

 

[fishslayerbob]

I was raised in a house filled with smoke and a 55 chevy filled with smoke. What??????????/

 

[jor-el]

This could be more trouble than it's worth, but suppose the bullets were pulled and moly coated? Along with this, there's a moly bore treatment as well.

An alternative would be to appeal to Wolf, Tula or Golden Tiger to change the specs of the jackets to something with thicker electroplated bi-metal jackets, or eliminate steel altogether?

 

[grumpy_old_man]

This could be more trouble than it's worth, but suppose the bullets were pulled and moly coated? Along with this, there's a moly bore treatment as well.

An alternative would be to appeal to Wolf, Tula or Golden Tiger to change the specs of the jackets to something with thicker electroplated bi-metal jackets, or eliminate steel altogether?

Hi Jor-el;

You're probably right on the cost issue. I hate to say it, but it would probably be cheaper just to stock spare bbl's for AR's. Numrich has mini 14 bbl, but you'd need to be a proper gunsmithy to install one properly. I'm just a poor hobbyist myself.

Thinking about it though, you're dredging up old memories with all this rifling/bullet composition talk. I vaguely remember an SOF article on the first AK74 brought back stateside back in the 80's and it's oddball new cartridge; interesting pic on the cover, since the rifle had lost its pistol grip smuggling it out of Afghanistan.

Anyway, they had a big writeup on the way the rifling was cut and how odd it was - IIRC there was a slant to the edges of the rifling that made it almost polygonal in character, i.e. instead of the edges of the lands being perpendicular to the grooves they slanted a bit. I wonder if that was to resist the extra wear and tear of a very hard .22 cal slug by minimizing stress risers? Course being the Russians under Soviet rule it could always have just been a manufacturing error.

Hmmm, does anyone make a polygonal bore 5.56x45 bbl for AR? If it was hard chromed too, that might seal the deal and make it a longer lasting bbl, even with the bimetallic jacketed slugs.

Just some thoughts.
Grumpy
PS Doesn't insomnia suck?