SS109 is not AP guys

[Double Tap]

O.K. The only reason I'm writing this is because there seems to be alot of discussion surrounding this projectile. The U.S. military calls this ammunition M855 "BALL" not AP and it is not I assure you considered light AP or Penetrator by the military. This is regardless of what you may read or hear from the shooting industry. There is a black tip AP round for .223 and M855 ain't it. This all started when the Belgians and the Swiss were concerned with the wound characteristics of the 5.56 X 45 in its M193 form. Eugene Stoner intended initially for the round to utilize a 55gr. bullet shot with a 1-14" twist so that the bullet would be highly unstable when it hit soft tissue. Well it was, there are many autopsy reports of finding enemy KIA's with their brains and abdominal tissue turned into "goo" because of this combination. That is when the twist was changed to 1-12". Well the Swiss wanted a "humane" bullet a projectile that would not upset and cause the horrible stretch cavity that the M193 had. Viola!!! the SS109 projectile was born. The steel TIP in the nose was supposed to keep the thing together and cause it to stay tip forward as it penetrated into a man's torso. That's all.

[Scott Jimenez]

yeah, funny thing is that if you keep the velocity above 2700 fps, both M193 and M855 have the same terminal ballistics. both fragment and the fragments tear the cavitating flesh creating huge wound tracts.
http://www.vnh.org/EWSurg/ch02/02Projectiles.html

scott out

[AR-45ACP]

[QUOTE]Originally posted by Double Tap:
"That is when the twist was changed to 1-12". Well the Swiss wanted a "humane" bullet a projectile that would not upset and cause the horrible stretch cavity that the M193 had. Viola!!! the SS109 projectile was born."

Are you saying that ss109 was designed with 1-12 twist in mind? if so is that why ARs went to 1-7"and 1-9"? because that stuff is inaccurate as all hell out of 1-12" guns like the hk93,fnc,ar180,etc always wondered why other countries that don't use ARs made this stuff.Mabey it is more humane because you can't hit anyone with your gun then -jay

[Double Tap]

I'm sorry I digressed. We, meaning the U.S. changed the twist to 1 in 12 in the attempt to stabilize the M193 projectile on early M16 rifles. The 1 in 7 twist was utilized primarily for the longer and even heavier M856 tracer round. But it was also useful because M855 was improved as well.

[Double Tap]

Scott, I have heard this. However, reading "Blackhawk Down" the Ranger's there complained of over penetration and ineffective knockdown power with the M855 stuff. Maybe you remember the part about having to pump 3-4 rounds into a Somali gunman before he would go down. I feel that the most effective combination in a .223 would be the 1 in 12 twist barrel with a 55gr. bullet regardless of the slightly better downrange performance of the heavier 62gr. bullet. But my FAL is my first choice:-).

[SodaPop]

While SS109 is not considered AP I sure as hell think it is. I stood next to a guy that put it threw a 1/4 inch steel plate at 100yds while his M193 bounced right off of it. I agree that switching to the 62gr did not improve anything but penetration. And at close range it reduced effectiveness.

[Scott Jimenez]

drawing conclusions from "Blackhawk Down" is problematic.

these were mostly combat inexperienced soldiers.

it has not been verified whether their rifles were actually M4's [14.5" 1x7" twist] or whether they drew XM177's [10 or 11" barrels with 1x12" twists usu.]. this would make a BIG diff in the performance of M855 at distances longer than CQB distance. muzzle velocity would drop below the 2700fps [and even the 2500fps] window for reliable fragmentation. you would not get the wounding benefits at all.

moreover, the 'detail' from the book is editorialized and may belie some bias. the writer is in no way an expert in researching the true details of equipment and performance.

7.62NATO performs well b/c it is a long, heavy bullet. ALL bullets tumble in media denser than air. do the stabilization calcs in flesh or gelatin and you can see that the twist needed is ridiculous. the wound track is usually a function of the rifle bullet flipping end over end trying to stabilize base first. if you stay over ~2000fps [kinda like the 'speed of sound in flesh'], you get cavitation. the cavitation stretches the tissues and the torn wound tract pulls open even more.

any heavy, fragmenting round [heavy to achieve complete penetration] will produce better wounding. better wounding puts down the target faster. a man wearing Level IV body armor, standing on one leg, will not be knocked down when shot w/ 30.06!!!!

scott out
PS. did i just ramble too much? <g>

Originally posted by Double Tap:
Scott, I have heard this. However, reading "Blackhawk Down" the Ranger's there complained of over penetration and ineffective knockdown power with the M855 stuff. Maybe you remember the part about having to pump 3-4 rounds into a Somali gunman before he would go down. I feel that the most effective combination in a .223 would be the 1 in 12 twist barrel with a 55gr. bullet regardless of the slightly better downrange performance of the heavier 62gr. bullet. But my FAL is my first choice:-).

[mark]

Who wants it to be classified AP???

Then there would be one more excuse for the liberals to prohibit it.

Bye, bye surplus.