U.S. Military Issue 5.56mm Ammunition
As far as my research went, the standard 5.56mm round used for rifles in the U.S. Military is the M855 Ball. Is that correct?
The actual question: How does this round gain it's effect? Does it have a single core, a double core like the german DM11, or something entirely different?
I attended a training about ammunition types and their capabilities a while ago which placed the lethality of the standard U.S. round below the supposedly superior DM11. I know there are concerns about the lethality of 5.56mm within the U.S. military, but it's hard to say if the DM11 would be more effective since there is only very limited info on it's actual performance in engagements. Any educated opinions on that?
I'm not sure if the construction really makes a difference (correct me if I'm wrong). The velocity, the mass, and the spin of the bullets are more important factors.
The original M16's impressive wounding power came from its round's ability to explosively fragment upon impacting the human body. It was an extremely light round (55-gr) fired at high velocity (3250fps) out of an M16 using 1 in 55 calibre rifling.
If the DM11 round is designed to break apart at the lower velocities of 5.56mm rounds used in 1 in 41 calibre twists, then, maybe it will be more effective than the M855.
M855 (62gr steel tiped FMJ) has penetrating power. M855 doesn't fragment as easy as M195 (55gr FMJ)would.
The M855 isn't an "all-steel" bullet. The tip of it is steel that is maybe 5mm long (guesstimate) and is backed by lead and jacketed by copper.
I cant vouch for its validity because I have no clue about this stuff. But its still interesting reading.
I dont know about DM11, who is developing that ? where ?
DM11 is the designation the german armed forces use for their standard issue 5.56mm rifle round. It has a steel core followed by a lead core. The steel core is supposed to provide penetration when required (body armor, unarmored vehicles, wood, etc.), while the lead core is supposed to increase lethality if the projectile strikes a softer target (unarmored person). Used together with the G36 since 1996.
It is produced in Switzerland by RUAG and used, as mentioned, by the German Bundeswehr. In addition to the double-core, it is slightly heavier than SS109 (~0.15 grams). From personal experience i can say it reliably fragments at at least 250 metres out of a 480mm barrel... on cardboard targets... if that means anything.
Originally Posted by dacanadianbomb
More info here.
The US tested a number of different 5.56x45mm loadings before settling on the variant of the FN SS109, M855, and selecting a long version of the tracer instead of the complimentry one (L110 vs SS110 to my understanding), as the M856.
US 5.56x45mm cartridges that I know of are:
M193: 56-grain FMJ
M195: Grenade launching blank
M196: 54-grain tracer
M197: 56-grain High-Pressure Test (or HPT)
M202: 58-grain FMJ (FN SSX822)
XM287: 68-grain FMJ
XM288: 68-grain tracer
M755: Special grenade launching blank for the M234 Ring-Airfoil Grenade (RAG) launcher
XM777: FMJ of unknown weight
XM778: Tracer of unknown weight (complimentry to the XM777)
XM779: XM287 PIP
XM780: XM288 PIP
M855: 62-grain FMJ (FN SS109)
M856: 63.7-grain tracer (FN L110)
M995: 52-grain AP
XM996: Dim tracer of unknown weight
Mk 262 Mod 0: 77-grain Open-Tipped Match (OTM)/Hollow-Point Boat Tail (HPBT) (Sierra Matchking bullet)
Mk 262 Mod 1: 77-grain OTM/HPBT (Nosler or Sierra bullet)
Isnt the M195 a 55gr FMJ??
No, you're thinking of 56-grain M193. The M195 is definite a blank designed for launching grenades.
I guess what I need is a cross section of the DM11 projectile.
I found this cross section of the M855, which apparently shows something which could lead to the same bullet being called "Doppelkern" == "Dual Core" in the german designation.
M855 cross section
Probably the nco who did the training was misinformed. I don't think there is any significant difference between DM11 and M855.
Judging from that pic: No. But the steel core of the DM11 seems to be marginally longer. And the DM11s jacket seems to be thinner, esp. at the tip... maybe that results in better fragmentation?
Originally Posted by Katana-sr
I heard of the German 7.62x51mm to have a thinner jacket and thus frag more frequently, maybe that's the case here, too?
here's the DM11 for comparison:
Penetrates a 3,5mm steelplate, Rockwell B55/77 @550m
Oh and the reason why the german 7,62x51 fragments so easyly is because the jacket is copper plated mild steel (Flu▀stahl) that tears up faster than copper, same with the DM11. Also the steel core is in the back iirc, and it deformates the lead upon impact, resulting in more shrapnell and deformation in soft tissue.
Last edited by Freibier; 02-11-2006 at 10:43 AM.
If the same Flu▀stahl vs. gilded metal difference is found between DM11 and M855,
Originally Posted by Freibier
it could indeed lead to the "West German 7.62mm effect"...
I realize, I should've posted this amazing source too, written up by D.E. Watters: http://www.thegunzone.com/556dw.html