View Full Version : 100 Grain 5.56 Rounds
Are specialized military units using a 100 grain 5.56MM round? A co-worker of mine had heard about an unnamed military unit using this round. I haven't heard of anyone using this weight. Any information would be appreciated.
Andrew
MisterWilson
09-16-08, 10:11
Haven't heard about anything like that but even 80gr pills have to be chambered individually if I'm not mistaken.
That would make make basically ammo for a bolt rifle, something that I think would be used in other calibers.
My personal opinion is that it's 100% BS but that's just me.
Now 70gr TSX brown tip, I've heard about those...
ETA: Wow, learned something new.
I remeber reading a post somewhere, and I belive it was writen by DocGKR and to paraphrase the 100gr 5.56 was a l110 tracer filled with lead, it need a twist rate more than 1in7 b/c it rainbowed. To end work was stopped when the 6.8 arived.
sorry about the spelling
The Ammo Oracle at TOS had photos of the 100gr bullet in question, along with a gel shot photo.
Failure2Stop
09-16-08, 11:16
From reports, not personal experience-
While demonstrating excellent terminal ballisitcs the round was not sufficiently stabilized with 1:7 twist rate, causing very poor accuracy.
At some point you have to question this nonsense. If you need a .308... GET a .308.
The 5.56 is never going to be a .308.
Here are a couple of items I found on the subject of 100gr 5.56 ammo. Apparently Black Hills has created a 100gr loading in 5.56 that has a velocity of around 2459 fps, and supposedly it shows great terminal performance.
However I cannot find much info about the Black Hills 100gr round. Here's what I did find:
* A listing from page 8 in this linked PDF file (http://www.texassmallarmsresearch.com/Info/556Performance/556Performance.pdf), which is from a site titled Texas Small Arms Research (http://www.texassmallarmsresearch.com). It shows a pic of the Black Hills 100gr round penetrating gelatin in testing.
* The new 100gr BTHP 5.56 ammo, loaded by Black Hills, is mentioned on this page (http://groups.msn.com/TheMarylandAR15shootersSite/556performance.msnw) in the Maryland AR-15 Shooters site. But no further details are given.
* This thread (http://www.professionalsoldiers.com/forums/showthread.php?t=9695&page=2) on ProfessionalSoldiers.com, mentioned the 100gr "experimental" Black Hills loading, but again, not much detail available.
It sounds like this thing already exists and is being used or at least tested somewhere, but is under wraps for now. The usage scenario is primarily as a CQB round.
The bullet was manufactured by Powell River Laboratories. PRL is now defunct.
There was some 100gr sub sonic at one point not sure if its still around.
MisterWilson- I think the brown tip I've heard of is not TSX but an improved RRLP (AA17). It has a FMJ to solve the feeding issues and I think a propellant change to help with the shorter barrels.
Black Hills says they were working on a 100gr round 'several years ago' but did not go forward with the project.
DocGKR mentions the 100gr 5.56 in his NDIA ppt, as I recall.
The long 100-grainers that ATK offered sucked as far as accuracy from a GI 1-7 barrel. You'd need at least a six-inch twist to stabilize them.
Powell River Laboratories loads a very heavy tungsten core bullet that flies true. They are very much in business, but like many companies their sales are almost exclusively to the US Government. At approximately $1 a bullet (just the projo) back in 2003 you can see why.
Sinister, thank you for the correction. I've been told bad information...
Dynamic Research Technologies.
Did PRL ever fix the QC issues with their 87gr Tungsten baby?
DRT (http://www.drtammo.com) appears to be producing the same PRL type powdered metal projectiles. The PRL 5.56 mm and 7.62x51 mm rounds offered superb accuracy and terminal performance, however PRL had some production and QC difficulties. Dr. Fackler presented a paper in the IWBA Journal discussing the 5.56 mm 76 gr PRL tungsten-tin core rifle projectiles: Fackler, ML: "Tungsten Frangible Bullet Wounds in Pig: Exam by Autopsy and X-Ray". Wound Ballistic Review (4)3:33-34 Spring 2000. We independently tested the 61 and 87 gr versions of the PRL bullet at the CHP Academy in late 1999 and had similar results. Ironically, the PRL/DRT bullets are a true "Blended Metal" bullet that actually works...
On the other hand, the 9 mm PRL handgun bullets did NOT offer increased terminal performance and behaved just like ball.
DRT just sent some of their current production handgun and rifle ammo--I'll post results in the near future, as we are in the midst of extensive testing right now.
I didn't know they ever had a problem.
We shot 87s at 600 for Rattle Battle and 1,000 in lieu of Sierra 80s and JLK 90s.
It was like stealing candy from a baby.
My predecessor, "Mac" Johnson put the ka-bosh on them because no other team could afford to load or shoot 'em. Wouldn't have been "Sporting" if you had an "Unfair advantage."
Fortunately there are lines of work where we're looking for overmatch.
The PRL line ran from 00 Buck and 9mm up to .45s, 300s, and 338s.
They're frangibles, so aren't good for anything behind any kind of cover.
There's a bounty of $25 a tail for each feral hog you harvest on Fort Benning. You can have great fun with PRLs on hogs out of M4s and MP-5s.
Ironically, the PRL/DRT bullets are a true "Blended Metal" bullet that actually works...
On the other hand, the 9 mm PRL handgun bullets did NOT offer increased terminal performance and behaved just like ball.
Doc, that's interesting. Is the problem with the 9mm just the fact that it's not able to fragment as effectively because it's not moving at long-gun-like velocities?
At some point you have to question this nonsense. If you need a .308... GET a .308.
The 5.56 is never going to be a .308.
It's not about getting a .308. It's more a matter of an improved round within an existing envelope. Our military is locked-in to the 5.56mm & 7.62mm. There will be new developments, loadings & weapons coming down the pike, but the harsh reality is that the military is not likely to go outside the AR15/M16 platform in our lifetimes. They'll spend millions on the latest greatest aircraft development, but anything to do with small arms just isn't sexy enough & gets a gets a big yawn from those that are spending our money. Since LEO typically follows military weapons, we tend to see the same old 5.56mm & 7.62mm weapons & loadings. Further development within these envelopes is a step in the right direction & the 5.56mm could use some improvement. The 6mm loadings show promise, but again we'll ultimately get nothing more than yawns within established channels.
Another example of an improved round within an existing envelope or platform is some of the ongoing development of the .243 Win. In many ways the .243 Win & similar rounds are superior to 7.62mm in bolt guns - as hard as that is for some to accept. The right 90 - 100 gr. in an established or improved .243 shows great promise as an LEO sniper weapon. The military will be saddled with the same old 7.62s & in machine guns it works just fine. They'll stick to the same caliber bolt guns due to logistics & supply. 100 gr. in an AR15/M16 platform might or might not be the answer, but I applaud their efforts to improve the AR's performance.
Dan Goodwin
09-28-08, 08:58
Another example of an improved round within an existing envelope or platform is some of the ongoing development of the .243 Win. In many ways the .243 Win & similar rounds are superior to 7.62mm in bolt guns - as hard as that is for some to accept. The right 90 - 100 gr. in an established or improved .243 shows great promise as an LEO sniper weapon.
Who is conducting ongoing development of the .243 Winchester for anti-personnel purposes?
I agree the round has great potential, but is anyone working on it for strictly that purpose?
RAM Engineer
11-06-08, 11:52
DRT just sent some of their current production handgun and rifle ammo--I'll post results in the near future, as we are in the midst of extensive testing right now.
Dr. Roberts,
Any info available yet on the DRT ammo?
Thanks,
Jason
The long 100-grainers that ATK offered sucked as far as accuracy from a GI 1-7 barrel. You'd need at least a six-inch twist to stabilize them.
Powell River Laboratories loads a very heavy tungsten core bullet that flies true. They are very much in business, but like many companies their sales are almost exclusively to the US Government. At approximately $1 a bullet (just the projo) back in 2003 you can see why.
Really interesting stuff - Hi Sinister (Kat from SCDR) - Rod told me about the ammo and this thread!
Ned Christiansen
05-23-12, 08:36
A couple years ago we fired one round of Extreme Shock 100-grain "SRT" into gel per FBI protocols, through light clothing. The chrono was not cooperating that day so no reading, but penetration was 31.5". Retained weight and bullet diameter were "no change". This may have been a subsonic, I don't remember. It's a pressed-metal material, so I reckon it turns to powder on anything hard. Not sure what this load would be good for.
Combat_Diver
09-14-14, 11:04
Was told that its a frangible load for CQB.
http://www.hunt101.com/data/500/medium/DSCF2147.JPG
CD
I was under the impression that an AR mag couldn't fit rounds above 80gr?
JBecker 72
09-14-14, 12:54
I was under the impression that an AR mag couldn't fit rounds above 80gr?
Reading the thread I'm assuming the weight is from the tungsten core. So OAL, I'm guessing, is less than an 80gr SMK.
Of course, it also helps that the manufacturers are purposely designing heavyweight projectiles to fit within the AR15 magazine. I believe that Berger was the first to use the term "LTB (Length Tolerant Bullet)" to designate which of their projectiles could be loaded to magazine length without forcing the ogive below the case mouth.
Combat_Diver, thank you for the photo! Not only did it remind me that I haven't been to this pub for awhile but there's nothing like seeing that familiar brown box with stripper clips ("stripper magazines?!") to get a better feel for its reality.
I think I'll be writing a message to Doc about a question I had some years ago about his opinions of the Barnes MPG now. Attached photo is an MPG from an ad which I accidentally hit an odd contrast combination. Still shadows but reminds me a little of an artificially colored 28539high-speed X-ray where the W powder is opaque.
Warning: Off topic and silly ahead - so you might skip this part:
Many years ago I was getting my NAUI and LA CO certs and on the checkout dive near the isthmus of Catalina I became for some exciting moments a combat-diver of sorts. A strong random current carried a small forest of kelp on me, couldn't budge, my young buddy swam off, my knife was on my calf and totally wrapped up. I'm okay at keeping calm but this was a new environment. I guessed I was using up fast what was left in my tank, so when I lifted my head for a second, bumped it into the keel of our boat and found myself staring at the 'intake' of both props, I knew I must have jumped another level in that video game! End the story not exciting, I finally got my knife, cut myself free (I bet I had too much loose gear including some air in the flotation vest). Got everyone's attention when I scolded at my teen partner (not for not hearing me tap on things etc) but for noticing I was gone, shrugging then enjoying the rest of his swim :P
Heavy Metal
09-14-14, 20:12
OT: Katgirl, I always carry at least two cutting implements when diving and make sure they are placed opposite. Normally, it is a knife on my right leg, EMT Shears in a Backplate waist strap mounted pouch on the left side. This way, if one side becomes fouled, I can still reach the other.
Combat_Diver
09-18-14, 07:16
katgirl,
Glad you made it out of that Kelp bed. I strap my dive tool down on the inside of my lower leg where I can reach it with either hand. Don't know if that would have worked in your senerio.
Here is some info I found online on the round.
http://www.hunt101.com/data/500/5_56mm.jpg
CD
rcoodyar15
09-18-14, 08:06
28573
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