Firearm & Gun Forum - FireArmsTalk.com > Long Guns > Auto & Semi-Auto Discussion > AR-15 Discussion > AR 15- take down power

Reply
 
LinkBack Thread Tools Display Modes
Old 10-02-2012, 08:39 PM   #21
Feedback Score: 0 reviews
 
SSGN_Doc's Avatar
 
Join Date: May 2012
Posts: 4,105
Liked 1963 Times on 1164 Posts
Likes Given: 423

Default

Quote:
Originally Posted by willfully armed View Post
You know this because you "read it" somewhere. They might forbid it, but it happens DAILY.





Navy sniper's (SEAL) are authorized to engage targets with the 5.56 mk 262(77gr SMK) round out to 800 yards.
The Mk262 and Mk262 mod1 rounds are allowed to be used because the hollow tip is not there to promote expansion but is the result of the process of making a very uniform jacket for match accuracy. The Hague accords restricted ammo designed to expand or cause undo suffering or injury. The fact that the jackets may fail and fragment is a side effect and not a design feature.

Kinda a fortuitous bending of the rules at most.
__________________

Last edited by SSGN_Doc; 10-02-2012 at 08:42 PM.
SSGN_Doc is offline  
 
Reply With Quote
Old 10-02-2012, 08:46 PM   #22
Feedback Score: 0 reviews
 
Join Date: Oct 2012
Posts: 176
Liked 27 Times on 21 Posts
Likes Given: 18

Default

Quote:
Originally Posted by JonM View Post
lighter bullets and faster twists are used at shorter ranges typically 350 or less for shooting varmints like prairie dogs and such where you want the speed to keep the trajectory flat as possible for a couple hundred yards. after that it bleeds off extremely rapidly making them very poor bullets for longer range stuff
In the context of this particular thread, 350 yards is long range. I wouldn't ever try to make shots at that range on an animal. What I was saying is, within that range (200 yards or less), the varminter twists are extremely accurate, moreso than the standard barrels with long twists. Most of them are made just effective enough for combat, not pinpoint accuracy on animals. And some people are under the assumption that an AR barrel = AR barrel, and .223 round = .223 round. Bullet weights need to be matched with the twist rate.
__________________
slog is offline  
 
Reply With Quote
Old 10-03-2012, 12:13 AM   #23
Feedback Score: 0 reviews
 
USEBOTHHANDS's Avatar
 
Join Date: Jan 2011
Location: Ferriday,LA
Posts: 1,332
Liked 650 Times on 368 Posts
Likes Given: 5125

Default

the theory behind FMJ rounds was they were never meant to expand, fragment, or come apart, they were designed to penetrate, create a hole, and ultimately, exit an enemy. the purpose of FMJ rounds was to NOT leave undue damage and destruction to the target.......nice neat hole in, nice neat hole out. they were developed to slow down or stop the enemy, and THEN take them off the battlefield to the nearest trauma/ER center.

with a "theorized" FMJ injury, a soldier would not suffer unduly, and could be fixed up and returned to the battlefield in a short period of time (taken with a grain of salt)......."live to fight another day."

NOW, compare that to a SP or HP round, these rounds basically mutilate and destroy whatever is in their path..........nice entry hole, 1 1/2 - 3 times the exit hole, with carnage in-between. you cannot compare the three rounds.

here is a brief on the .223/5.56 argument, from Wiki, but non-the-less, an "account" of the arguments summed up.

As for SSGN_Doc's comment on the Mk262 OTM rounds, it is addressed in the below. BUT, to sum it up, the M855 (62 grain FMJ) rounds weren't reaching maximum ballistic performance because of the shortened rifle lengths.......the M855 rounds were created around a 20-inch barrel (and to a lesser degree "functioned" OK, in a 16-inch barrel). with the shortenin of barrels for the military M4's, the velocity of the projectiles was lost, thus decreasin the ballistic performance of the rounds @ yard. a new round was created around the M4 barrel lengths, and the ballistic performance was regained..........somewhat.

Criticism
There has been much criticism of the poor performance of the bullet on target, especially the first-shot kill rate when the muzzle velocity of the firearms used and the downrange bullet deceleration do not achieve the minimally required terminal velocity at the target to cause fragmentation.[19] This wounding problem has been cited in incidents beginning in the first Gulf war, Somalia, and in the current conflicts in Iraq and Afghanistan. In recent lab testing of M855, it has been shown that the bullets do not fragment reliably or consistently from round-to-round, displaying widely variable performance. In several cases, yawing did not begin until 7–10 in of penetration. This was with all rounds coming from the same manufacturer.[19] This lack of wounding capacity typically becomes an increasingly significant issue as range increases (e.g., ranges over 50 m when using an M4 or 200 m when using an M16) or when penetrating heavy clothing, but this problem is compounded in shorter-barreled weapons. The 14.5 inches (37 cm) barrel of the U.S. military's M4 carbine generates considerably less initial velocity than the longer 20" barrel found on the M16, and terminal performance can be a particular problem with the M4.
Combat operations the past few months have again highlighted terminal performance deficiencies with 5.56×45mm 62 gr. M855 FMJ. These problems have primarily been manifested as inadequate incapacitation of enemy forces despite them being hit multiple times by M855 bullets. These failures appear to be associated with the bullets exiting the body of the enemy soldier without yawing or fragmenting.
This failure to yaw and fragment can be caused by reduced impact velocities as when fired from short barrel weapons or when the range increases. It can also occur when the bullets pass through only minimal tissue, such as a limb or the torso of a thin, small statured individual, as the bullet may exit the body before it has a chance to yaw and fragment. In addition, bullets of the SS109/M855 type are manufactured by many countries in numerous production plants.
Although all SS109/M855 types must be 62 gr. FMJ bullets constructed with a steel penetrator in the nose, the composition, thickness, and relative weights of the jackets, penetrators, and cores are quite variable, as are the types and position of the cannelures. Because of the significant differences in construction between bullets within the SS109/M855 category, terminal performance is quite variable—with differences noted in yaw, fragmentation, and penetration depths. Luke Haag's papers in the AFTE Journal (33(1):11–28, Winter 2001) also describes this problem.
—[19]
Despite complaints that the 5.56 round lacks stopping power, others contend that animal studies of the wounding effects of the 5.56×45mm round versus the 7.62×39mm have found that the 5.56 mm round is more damaging, due to the post-impact behavior of the 5.56 mm projectile resulting in greater cavitation of soft tissues.[20] The US Army contended in 2003 that the lack of close range lethality of the 5.56×45mm was more a matter of perception than fact. With controlled pairs and good shot placement to the head and chest, the target was usually defeated without issue. The majority of failures were the result of hitting the target in non-vital areas such as extremities. However, a minority of failures occurred in spite of multiple hits to the chest.[21]
[edit]
Improvements
Recently, advances have been made in 5.56 mm ammunition. The US military has adopted for limited issue a 77-grain (5.0 g) "Match" bullet, type classified as the Mk 262. The heavy, lightly constructed bullet fragments more violently at short range and also has a longer fragmentation range.[22] Originally designed for use in the Mk 12 SPR, the ammunition has found favor with special forces[23] units who were seeking a more effective cartridge to fire from their M4A1 carbines. Commercially available loadings using these heavier (and longer) bullets can be prohibitively expensive and cost much more than military surplus ammunition. Additionally, these heavy-for-caliber loadings sacrifice even more penetrative ability than the M855 round (which has a steel penetrator tip). Performance of 5.56×45mm military ammunition can generally be categorized as almost entirely dependent upon velocity in order to wound effectively. Heavy OTM bullets enhance soft tissue wounding ability at the expense of hard-target/barrier penetration.
For general issue, the U.S. military adopted the M855A1 round in 2010 to replace the M855. The primary reason was pressure to use non-lead bullets. The bullet is made of a copper alloy slug with a steel penetrator, reducing lead contamination to the environment. The M855A1 offers several improvements other than being lead-free. It is slightly more accurate and has an increased penetrating capability. The round can better penetrate brick, concrete, and masonry walls, as well as body armor and sheet metal. The propellant burns faster which decreases the muzzle flash, an important feature when fired from a short barreled M4 Carbine. Though the M855A1 is more expensive to produce, its increased performance compensates. One possible danger is that it generates more pressure in the chamber when fired, slightly increasing the risk of catostrophic failure of the weapon, though this has yet to occur.[24] From fielding in June 2010 to September 2012, Alliant Techsystems has delivered over 350 million M855A1 Enhanced Performance Rounds.[25]
[edit]
Alternatives
If the 5.56mm bullet is moving too slowly to reliably fragment on impact, the wound size and potential to incapacitate a person is greatly reduced. There have been numerous attempts to create an intermediate cartridge that addresses the complaints of 5.56 NATO's lack of stopping power along with lack of controllability seen in rifles firing 7.62 NATO in full auto. Other cartridges focused on superior short-range performance by sacrificing long-distance performance due to relatively short engagement distances typically observed in modern warfare. As of late 2009, none of those cartridges gained any significant traction beyond special forces and sport shooting communities. Examples include, but are not limited to, the 6.8mm Remington SPC and 6.5mm Grendel.

__________________

"they may get me in a rush, but not before i turn your head into a canoe....." -Kurt Russell (Wyatt Earp) in Tombstone

"if it was up to me, i'd like to see, this country run,
the way it used to be, the way it oughta be, just like it's done, OUT HERE.........WAY OUT HERE." -Josh Thompson, country music singer http://www.youtube.com/watch?v=D0sYnro_3Rc
http://www.youtube.com/watch?v=P3R00rlA0S0&NR=1

PEOPLE TEND TO ACT LIKE SHEEP, BOY I LOVE MUTTON! -Me


Last edited by USEBOTHHANDS; 10-03-2012 at 12:22 AM.
USEBOTHHANDS is offline  
 
Reply With Quote
Old 10-03-2012, 12:36 AM   #24
Feedback Score: 0 reviews
 
kryptar19's Avatar
 
Join Date: Oct 2011
Location: arkansas
Posts: 1,703
Liked 600 Times on 358 Posts
Likes Given: 1304

Default

A high grain Hornady v-max (60gr and up) will kill a deer out to 250yds easy. It makes the insides look like blended jello. IMO its the best way to go for a .223.

__________________
kryptar19 is offline  
 
Reply With Quote
Old 10-03-2012, 12:46 AM   #25
Feedback Score: 0 reviews
 
kryptar19's Avatar
 
Join Date: Oct 2011
Location: arkansas
Posts: 1,703
Liked 600 Times on 358 Posts
Likes Given: 1304

Default

Quote:
Originally Posted by kryptar19
A high grain Hornady v-max (60gr and up) will kill a deer out to 250yds easy. It makes the insides look like blended jello. IMO its the best way to go for a .223.
A 55gr v-max does ok tho. I reload a 62gr V-max with 27.5gr of BL-C(2). If anyone wants a good load.
__________________
kryptar19 is offline  
 
Reply With Quote
Old 10-03-2012, 12:50 AM   #26
Feedback Score: 0 reviews
 
kryptar19's Avatar
 
Join Date: Oct 2011
Location: arkansas
Posts: 1,703
Liked 600 Times on 358 Posts
Likes Given: 1304

Default

A 55gr V-max will do ok too. I load a 62gr V-max with 27.5gr of BLC-(2), if anyone wants a good load..

__________________
kryptar19 is offline  
 
Reply With Quote
Old 10-03-2012, 12:52 AM   #27
Feedback Score: 0 reviews
 
kryptar19's Avatar
 
Join Date: Oct 2011
Location: arkansas
Posts: 1,703
Liked 600 Times on 358 Posts
Likes Given: 1304

Default

Stupid phone double posting. My bad

__________________
kryptar19 is offline  
 
Reply With Quote
Old 10-03-2012, 02:15 AM   #28
Lifetime Supporting Member
FTF_LIFETIMESUPPORTER.png
Feedback Score: 1 reviews
 
Vikingdad's Avatar
 
Join Date: Mar 2011
Location: Santa Cruz Mountains,CA
Posts: 13,446
Liked 7736 Times on 4468 Posts
Likes Given: 9983

Default

One of the theories behind using the .224 caliber round was that wounding an enemy combatant would take three men out of the battle (two men to carry off the wounded soldier) but the Commies didn't fight that way and left their wounded on the battlefield while continuing to fight. At the same time the Commies were continuing to use the 7.62 rounds which killed more Americans and our allies. That is one theory anyhow.

__________________
Vikingdad is offline  
USEBOTHHANDS Likes This 
Reply With Quote
Old 10-03-2012, 11:24 AM   #29
Moderator
FTF_MODERATOR.png
Feedback Score: 0 reviews
 
JonM's Avatar
 
Join Date: Nov 2009
Location: Rochester WI,Rochester WI
Posts: 17,129
Liked 5272 Times on 2748 Posts
Likes Given: 333

Default

When used out of a 20" barrel the 556 military chambering is an effective manstopper out to 300 yards and marginal beyound that. When the barrel drops to 14.5 (m4 carbine) that range drops drastically. Deer are substantially tougher than humans. And require a direct to the heart to stop them in a reasonable running distance.

In combat if a bullet hits an enemy the soldier shooting the enemy isnt tracking that soldier down for body recover in order to akin and eat the enemy soldier. It doesnt matter if that enemy crawls off a mile or two and dies much later or not. He is effictively out of the fight. Lighter bullets allow mich more ammunition carried both in transport vehicles and by soldiers for less weight.

The needs of deer hunting are far different. My opinion is that the 556 is a superb war round and a fantasticly accurate target round but incredibly marginal as a hunting round. Use s bigger cartridge for hunting.

__________________

"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith

The problem with being stupid is you cannot simply decide to stop doing dumb things...

JonM is offline  
USEBOTHHANDS Likes This 
Reply With Quote
Old 10-03-2012, 12:27 PM   #30
Feedback Score: 0 reviews
 
treehugger49's Avatar
 
Join Date: Apr 2009
Location: Newnan,Georgia
Posts: 421
Liked 42 Times on 36 Posts
Likes Given: 2

Default

Debate about the .223's lethality at what ranges aside, I haven't seen this point mentioned....

Check your state's laws pertaining to minimum caliber for big game hunting. Many states don't allow the .223.

__________________

XD-40 service, XD-9sc, member GeorgiaCarry.Org, National Rifle Association, Gun Owners of America, North American Hunting Club, Rocky Mountain Elk Foundation

treehugger49 is offline  
 
Reply With Quote
Reply

Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Firearms Forum Replies Last Post
Enough Power? PowderBurnBassist General Rifle Discussion 44 09-30-2011 05:28 AM
Very low power to moderate power scopes Marlinman Optics & Mounts 7 09-29-2011 03:03 AM
New (to me) Hi Power utf59 Range Report 7 07-02-2011 01:04 PM
To Much Power Woodsman The Club House 6 02-10-2009 01:27 AM
Hi-Power Fayettedave Semi-Auto Handguns 7 11-18-2008 03:57 AM