Just curios as I have picked up on this in a few threads. If so what is it? Surely its not just the couple extra grains of bullet weight.
Thanks,
Jason

M856 tracer does not have the steel penetrator tip found in M855.

http://www.ar15.com/archive/topic.html?b=3&f=16&t=524028

According to this video, is sure does (when talking barrier penetration, specifically wood):

Will tracers cause additional barrel wear? Does it ignite while still in the bore or once it hits open air?

No, it won't cause additional barrel wear.  The tracer compound won't ignite until it the round travels at least 50 yards.

Looks like it preforms well in Gel too!  Would be interesting to do some additional gel and penetration tests.

https://www.youtube.com/watch?v=-u5Uk0ae4p4

My local cabelas had two shelves full of M856, no clue why they'd have that much. Went back a week later and not a single box to be found. I'm guessing federal sent the wrong shipment, but damn I shouldve picked up a few boxes while I had the chance

They penetrate like crazy!!

https://www.youtube.com/watch?v=aLitgXZnjjw

1) That gel test looks bad. No fragmentation. Further, the gel was almost doubtlessly too warm if it came apart like that.
2) While the tracer pellet is said not to cause barrel wear, the steel jacket may indeed wear the barrel faster than M855.

Looks bad?

Brassfetcher is one of the premier ballistics gel testers in the country.  If any gel test is conducted with stringent procedures by the books, its his.

A round doesn't have to fragment to be effective, that is simply one (not always entirely consistent) wounding mechanism.  Do softpoints fragment?  Does the 5.45 round fragment?  I would do a little bit more research on terminal performance in general if I were you.

Believe what you want to believe. Ordnance gel rarely behaves that way when kept at the correct temperature.

I'm not worried about the opinion of someone who thinks soft point, hollow point, and 5.45 rounds are not ballistically effective because they don't fragment.  

The highly effective 5.56 soft points and hollow points expand significantly, or in the case of Mk318 and Mk262, fragment.

You will not find a non-expanding, non-fragmenting 5.56 load that is reccomended by actual SMEs such as Dr. Roberts.

If you are suggesting 5.45 7n6 has anywhere near the terminal effects of Mk262, Mk318, M855 (when it fragments) or 8m3, you need to research the matter more.

If you want a non-fragmenting, non-expanding round which depends solely on yaw for enhanced terminal effect, just buy Wolf steel cased .223 and save a bunch of money.

Interesting.  

I have heard that actually Norinco's old .223 steel jacket 55 grain FMJ had an interesting unknown mechanic that caused it to yaw early, and consistently, resulting in devastating wounds. Link



Are you suggesting that wolf's .223 fmj ammo shares that same dynamic?  I don't believe I have seen any gel, or terminal performance tests with .223 fmj wolf.

Nope.

Your link is full of fallacies, myths and legends, not facts.

May I suggest you read the works of Dr. Fackler as a primer on actual terminal effects knowledge, followed by the research of Dr. Roberts?

OP asked about penetration.

Depends on what you want to penetrate. I wouldn't expect it to penetrate the NIJ Level III Poly plates, which M855 can sometimes penetrate. However, testing on that would be required to confirm.

So Brassfetcher gelatin is twice as stiff. Correct?

Twice as thick. Stiffness on ordnance gel has a lot to do with temprature. It's supposed to be kept cold. Let it get warm and it behaves very differently.

I'm referencing the fact that whatever the mechanism, it seems to exhibit stellar terminal performance.  When you mentioned that wolf .223 exhibited excellent yaw characteristics, that old article's write up on norinco instantly popped to mind, which is why I asked you to elaborate on your wolf comment....which you have neglected to do.  

Why don't you start a new thread about your article? I promise I will respond to it if you do. The mods have asked that this thread stay on topic.

So it does seem to be quite a fair penetrator.

procedure:

10 velocity tests on the rounds were conducted using an Oehler Research 35P chronograph 15 feet from the muzzle.

After some alignment shots, targets (bare gel blocks) were placed 16 feet from the muzzle and each subjected to a single round. Velocity of the projectile was again measured at 15 feet, 1 foot before the gelatin block.

Multiple blocks were shot. We are now out of gel and have to buy a bunch more. This bothers Dr. Tatjana because gel is made from Horsies.

The blocks were examined, photographed and then dissected into slices. Slices were photographed to measure and record wound profile size. Fragments were then extracted and their penetration depth measured and recorded. Fragments were organized according to penetration depth and photographed to record fragment distribution throughout the wound cavity.

The ammunition was quite consistent in gel- but not the way you might think. Probably as a result of the length of the round, all shots exhibited a significant course deviation mid-gel and just after yaw, before exiting the side of the gel block at around 12-13"

Results notes/Observations:

Velocity of the displayed gel shot was 2954 fps.

Fragmentation of the rounds was nearly absent.

Total penetration (before exit from the block) averaged 12.5" and would probably exceed 13.5" if not for bullet exit.

Neck length (as defined by distance before a significant degree rotation of the round) was generally around 5.75-6".

The largest recovered fragments typically appear to be the bullet's base and rear jacket structures and core.

Recovered materials included 0.2gr of ash and 50.6gr of jacket/core. Given the lack of fragments it seems clear that upwards of 10gr of bullet weight is tracer element.

Wound cavity size at its extreme was a dramatic 6.3" at inch 7. This is probably the result of the unusual length of the round.

Recovered Weight:



conclusions:

Surprisingly the M856 does not fragment well at all. Minimal fragmentation was observed even at 16" muzzle velocity. Despite this the round does leave a rather impressive wound cavity, though it is not until deep in tissue (6-7") that the cavity opens up significantly. Accordingly, the round is not recommended for self defense applications.
Other notes and observations:
Total lack of fragmentation was extensive enough to cause Dr. Brouhaha (hee!) to dance for joy before the extraction process. Immediately after the shot he was heard to exclaim: "Ah HA!" This is generally an indicator of poor levels of terminal performance.
The orange paint used to distinguish the M856 tracer was left smeared inside the first 1-1.5" of the wound cavity. Dr. Tatjana will consult with S.P.E.C.T.E.R. about developing toxic paint coatings for future deployment.
Tracer elements appear to light IMMEDIATELY (10-20 meters) after exiting the barrel. Much past discussion about a 50-100 meter delay (including field manual notes) seems to be inaccurate.
We did not observe any scorching of the gel block, though the tracer element exited the block before coming to a rest and burning on some of the backstop material. Dr. Brouhaha will be reupping his fire insurance immediately.  
Damage (temporary/permanent cavity) to the blocks were often so severe in the 5-7" range that sectional slices were hard to hold together.  
Note: Neither Dr. Tatjana nor Dr. Brouhaha are Doctors of anything, they have, however, stayed at Holiday Inn Expresses.