WARNING: Independence 5.56 Ammo

[StealthyBlagga]

One of our local Match Directors pulled me aside at today's 3-Gun match and told me about a test he did with some Independence 55gr FMJ ammo. He shot one of our 3/8" AR500 steel plates with this ammo out of a 20" AR15 at 50 yards (the minimum safe distance for rifle on steel at most matches)... apparently the bullet very nearly punched right through. He confirmed that the projectile does not attract a magnet, so per our rules it would be legal. We suspect this load exhibits unusually high velocity which is contributing to the increased damage on the target. There are lots of reports online about blown primers with this ammo, which seems to support our theory.

 

We are going to chronograph the ammo to see what it is actually doing. If indeed velocity is the problem, we may have to institute a speed cap for rifle ammo at our matches. Unfortunately, Federal is offering generous rebates on this stuff right now, so we may see it more often than before. For the moment, this is just a heads-up to be cautious with this ammo - competitors because of blown primers and wear on the gun, MDs for target damage.

[NoKimberDave]

20" AR at 50 yards is pretty close. I have seen an 18" rifle put Fed 55FMJ right through a plate at about 50, when 3 other people were shooting same plate with same ammo out of 16" AR's!!

It sure had us scratching our heads! Don't really have an answer to "why" and the only thing I could come up with is "velocity" in this case.

 

Indeed the independence is junk. I just thought it was loose primer pockets. Hadn't occurred to me that it could be a lot hotter. Will be interesting to see your findings.

[Nathanb]

Speed kills. 

[Woodsk]

Independence has had high pressure problems for years, I'm surprised nobody has gotten hurt from a KB yet   

[ericm]

WARNING: YOU'RE GONNA GO DOWN THE RABBIT HOLE HERE!!!!

 

This talk of CERTAIN .223/5.56 ammo being too fast is NUTS! (overpressure notwithstanding)

The spec for 55 gr FMJ is 3240 FPS +/- 70 FPS or thereabouts out of a 20" bbl.

I've heard rumblings and rumors of banning: Federal XM-193, Wolf Gold, IMI M-193 etc. etc.

THESE ARE ALL THE STANDARD LOAD FOR .223/5.56.

 

Now, instead of an easy test for magnetic projo's, yer gonna need a chrono.

(And, by the way, the whole magnetic projo witch hunt is just that, a witch hunt, IMHO - has anyone here priced REAL HONEST-TO-GOD ARMOR PIERCING AMMUNTION lately??? And can anyone here get their hands on enough REAL AP to shoot a match with??? I know I can't even find it...)

 

So what's the limit????? 3200 fps?, 3000 fps? 2800 fps??? Bullet weight limits????

 

OR....OR....do we just acknowledge that steel targets are a CONSUMABLE item just like cardboard, tape, paint, etc.

Target steel at 50 yds will be "consumed" more quickly than at 200 yds...and I've shot a bunch of 7N6 and M855 at steel with NO DAMAGE....and enough people say this same thing to at least offset the folks that squeal "STEEL KILLER!" every time a magnet sticks to a bi-metal jacket.

 

LEAVE MY 55 gr. SIERRA BLITZKINGS @ 3240 fps ALONE!!!!

 

ericm

[nguySBR1]

Another solution: don't place rifle steel targets closer then 200yards. 

 

 

Or as stated by ericm, steel targets are also a consumable item and will need replacement more often when used at closer distances.

[mpeltier]

On 8/17/2017 at 9:48 AM, nguySBR1 said:

Another solution: don't place rifle steel targets closer then 200yards. 

 

 

 

This is the only sensible solution. Though 100-150 yds would probably be ok. 50 yds is just a bit close. at our range rifle steel is seldom closer than about 100 yds. on the rare occasion its closer we put out the garbage steel that is near the end of its life span anyway.

[ericm]

Just crunched some numbers on my Oehler Ballistic Explorer:

 

A 55 gr. Hornady FMJ bullet starting at 3240 fps at our rarified atmosphere of a mile high (5300' - which will make retained velocities higher than sea level) has the following remaining velocities:

50 yds : 3069 fps

100 yds : 2905 fps

200 yds : 2594 fps

300 yds : 2304 fps

 

When we hit the full sized IPSC target w/ strobes @ 530 yards at RM3G this year (7000' ASL), a 55 gr. Sierra Blitzking  @ 3240 fps was moving at about 1850 fps.

 

ericm

[StealthyBlagga]

Most MDs understand that steel is semi-consumable... we just don't want it to become TOO semi-consumable  . At my home range, we are blessed with a plentiful supply of steel targets, but not all ranges are so lucky. Many MDs with limited budgets will want their precious resources to be preserved as much as is reasonably practicable. I have not seen a lot of data on how velocity can affect steel target life, so I wanted folks to be aware.

 

Other than accelerated target degradation, there is nothing wrong with putting rifle steel at 50 yards. It gives us a lot  more options for stage design while maintaining acceptable shooter throughput.

[PacMan]

Solution - Outlaw 20" barrel ARs and all "193" speed problems would go away   Eric, put down your JP CTR02! 

Seriously, just keep steel targets where they belong - out there beyond the 100 yds mark, or expect dings and dimples.  The un intended consequence of putting steel at short range <100 yds, most shooters would use 'cheap' stuff and '193' FMJs are now plenty cheap, you are going to see more dings in those thin steel targets.

[The Donald]

One thing that helps a target live in the 50 yd. range is have it move like on a plate rack. A lot of energy gets used up knocking something over. Also 50 yd. rifle targets should be pretty small, you don't need to shoot 'C' zones at 50 yds.

[kurtm]

Not that I really care, but I was involved in designing a range for the U.S. Marshall's service and several tribal police entities. They needed steel that could live at 15-25 yards (C zone sized). They had LOTS of M-855 and M-193 ball ammo. I found that if you could get the plate, think C zone, to lean at about 20-25 degrees from vertical, they "lived" for a very long time. All the splatter and frags went down, nothing came back, and training proceeded.

This whole thread to me is pointless. The "service envelope" of 5.56x45mm has been well known since 1958 and only now people have "figured out" that the velocity is really high???

Plan for it! Design your target system around it, but at this late a date to post something as ignorant as saying " over speed" in relation to ammunition that meet the specification for military ammunition is.........well....... IGNORANT!

 

Edited August 20, 2017 by kurtm

[StealthyBlagga]

Them's fightin' words... only my wife is allowed to call me ignorant 

 

Our 50 yard steel hangs as Kurt describes, at a downward-facing angle hanging on rebar stands or fire hose. They have some "give" when hit too, though their inertia means they still take a pounding no matter what we do. The faces get chewed up and the edge look like a postage stamp's perforation, but they have given us years of service. We just take notice when we start seeing a marked increase in damage. As most of us already knew, velocity can be more of an issue than bullet construction at these distances. I love my fast 55s as much as anyone, and we already see a lot of M193 ammo being used, but this Independence ammo stood out.

Edited August 20, 2017 by StealthyBlagga

[ericm]

Presented with only one comment: Dig those shootin' glasses!!! 

 

https://www.youtube.com/watch?v=7EGufcEje6U

 

 

ericm

[kurtm]

I say PIFFL to your scrawny master lock. 

 

Just sozs youz guyz know. it is damn hard to get a 55 grain bullet anywhere past 3300 without leaving lots of primer bits in the gun out of a 20" barrel. There simply isn't enough case capacity for powder to do this. Also in many instances more powder doesn't really relate to a lot more velocity, it just creates more pressure at the peak pressure. You can see this with boring regularity with a chrono.  223.  will climb and climb in velocity until you hit the pressure  plateau. Then you will flatten and drop primers and blow cases with less than a 50 FPS gain. Also if you had kept chronoing you would find significant velocity drops when the primer pierces and drops out due to leaking. If you all notice most all mil spec 223 brass has fairly loose primer pockets! HMMM wonder how close they are to the plateau?

 

[StealthyBlagga]

UPDATE:

 

This ammo chronographed at 3370fps out of a 20" AR15 . Conditions were typical for the Phoenix AZ area right now: >100 degF, ~1000ftASL.

 

Here are some photos of the impact on our AR500 plate at 50 yards. This plate is never used beyond about 60 yards, and the other impacts are what we typically see with a diverse range of ammo (probably the majority is other brands of commercial M193 and similar loads). The Independence-brand impact stands out for the depth of its crater, and particularly for the back-face deformation. This is actually worse damage than we saw when the same plate was shot with M855A1 out of a 16" barrel.

 

FRONT:

 

 

BACK:

 

Edited August 23, 2017 by StealthyBlagga

[Hi-Power Jack]

Thanks for sharing - not going to take too many of those rounds to

ruin that piece of steel, at that range.

 

Good to know.    

[Religious Shooter]

100 degrees!  

 

Next time bring an ice box filled with ice and stick some Independence ammo in a plastic bag and let it cool down.

 

After it cools down take one out and immediately fire it.  It would be cool to find out to see if it is the 100 degrees! that's putting it over the top.

 

It's also probably the lot.  Israeli made?

[NoKimberDave]

Very interesting findings.

 

 

[Balwolley]

I know that I'm picky with my long range rifle powders.   Temperature sensitivity is a real thing and some powders are sensitive.   Like was stated above, I would like to see if there's a big difference from 100 degree ammo vs say 40degree ammo

[Stlhead]

What is the thickness of the plate, and are you certain it is actual AR500?  Fast barrel, tight chamber, hot day, 3370 is not that crazy for full power 55's.  Are you thinking of adding a max speed limit?

[StealthyBlagga]

18 hours ago, Religious Shooter said:

100 degrees!  

 

Next time bring an ice box filled with ice and stick some Independence ammo in a plastic bag and let it cool down.

 

After it cools down take one out and immediately fire it.  It would be cool to find out to see if it is the 100 degrees! that's putting it over the top.

 

It's also probably the lot.  Israeli made?

 

3 hours ago, Balwolley said:

I know that I'm picky with my long range rifle powders.   Temperature sensitivity is a real thing and some powders are sensitive.   Like was stated above, I would like to see if there's a big difference from 100 degree ammo vs say 40degree ammo

 

Temperature sensitivity could be a factor (though Israel is hot too, so I would have thought they select their powder with that in mind). In any case, we get the barrel pretty hot in our game, and the thermal mass of a brass case is not great, so I can imagine a chambered round getting that hot even in mid-winter Alaska at the end of a typical stage. 

Edited August 24, 2017 by StealthyBlagga

[StealthyBlagga]

2 hours ago, Stlhead said:

What is the thickness of the plate, and are you certain it is actual AR500?  Fast barrel, tight chamber, hot day, 3370 is not that crazy for full power 55's.  Are you thinking of adding a max speed limit?

 

Yes, genuine 3/8" AR500 target plate. Looking at the other hits on the plate will show that it is quite resistant to a variety of centerfire rifle rounds at the same distance. We have made no decision on a speed limit - as Eric pointed out, this would be difficult to police (we have enough trouble catching ammo that attracts a magnet). Right now, my thinking is that 20" guns are rare these days, and this ammo will come and go. If we start seeing a significant increase in target damage, we may have to re-evaluate, but hopefully that won't be necessary as we don't need more rules if we can help it.

 

Perhaps a bigger consideration for competitors is the extra stress this ammo puts on the gun - a friend messaged me when he saw this thread, and let me know he has seen lots of different ammo over the years, notably from Israel, that has been loaded hot and is very hard on the gun... he reports several cases of broken bolts (which will bring one's stage to a grinding halt).

Edited August 24, 2017 by StealthyBlagga

[ericm]

2 hours ago, StealthyBlagga said:

he reports several cases of broken bolts (which will bring one's stage to a grinding halt).

 

Even after all those 1000's of XM193 (when it was cheap) and my full on 55 gr. reloads, I've yet to see a broken bolt.

Just lucky, I guess.

I can only imagine what a case of broken bolts looks like, much less several cases (assuming 500 bolts to a case?)

 

ericm

Edited August 24, 2017 by ericm

[ziebart]

I've seen three broken bolts, one of which was mine. Not sure that hot ammo was the cause. JP said they just wear out over time.