The OK case

[fredtoast]

(04-04-2017, 12:03 PM)michaelsean Wrote: https://www.youtube.com/watch?v=X0qgQoej5zE

http://preparedgunowners.com/2016/07/14/why-high-powered-5-56-nato-223-ar-15-ammo-is-safer-for-home-defense-fbi-overpenetration-testing/

seems the military weapon is safer due to the tumbling of the .223.  Now I know very little about firearms, which is why I asked the question in the 1st place so if Breech or bfine or SSF or Matt want to chime in on this, feel free.

.223 is actually a small bullet.  So that might be true.

[*michaelsean*]

(04-04-2017, 03:00 PM)fredtoast Wrote: .223 is actually a small bullet.  So that might be true.

That's what most of these military rifles shoot isn't it?

[*michaelsean*]

(04-04-2017, 02:52 PM)BmorePat87 Wrote: I don't know a thing about guns, but the answer to your question varies by locality. I am installing a doorbell camera with an additional camera for my back door that send me videos anytime someone comes around. I figured since day time break ins are more common, this is a good security device. I also can talk via the camera, so when my phone alerts me that someone is at my front door, I can call the police and tell them via the speaker that the police are coming. 

I have a large loud dog.  To my mind, that's better security than even a gun.  Most people won't even bother.

[Belsnickel]

(04-04-2017, 02:20 PM)hollodero Wrote: Americans talking guns. Never do I feel more estranged to you.

I don't wat to interrupt though - just one quick question: How big of a problem are heavily armed intruders?

Not much, and even smaller when you consider that most break-ins are for robbery and if you just let them take your shit, no one gets hurt. I'm of the "barricade and them have the material possessions" kind of approach. Material things aren't worth a human life, even that of the person stealing them.

[oncemoreuntothejimbreech]

(04-03-2017, 10:47 PM)michaelsean Wrote: So what is the formula that says effective military weapon equals poor choice for self-defense?

There isn't a formula.  It's a subjective opinion based upon knowledge, experience, personal preference, yada, yada, yada.  If you ask ten different gun enthusiasts you will most likely get ten different answers.

(04-04-2017, 12:03 PM)michaelsean Wrote: https://www.youtube.com/watch?v=X0qgQoej5zE

http://preparedgunowners.com/2016/07/14/why-high-powered-5-56-nato-223-ar-15-ammo-is-safer-for-home-defense-fbi-overpenetration-testing/

seems the military weapon is safer due to the tumbling of the .223.  Now I know very little about firearms, which is why I asked the question in the 1st place so if Breech or bfine or SSF or Matt want to chime in on this, feel free.

When it comes to over penetration we have kinda covered this ground before.

http://thebengalsboard.com/Thread-%E2%80%98Military-Style%E2%80%99-Firearms-Aren%E2%80%99t-Protected-By-Second-Amendment-Court-Rules?highlight=penetration

All my exterior walls are brick so I'm not concerned with overpenetration due to a .223/5.56 AR-15 killing my next door neighbor.  I'm more concerned about overpenetration shooting the guy standing in my living room causing a through and through wound because I'm shooting him with less than 20 feet of stand off with a muzzle velocity of approx. 3000 ft/sec.  As we covered before, ammo selection plays an important role whether you get overpenetration or not.  (You don't want a through and through round because it causes less damage.)  There are various combinations of ammo and weapons all with pros and cons which may or may not cause overpenetration of the target or surrounding structures.  It basically boils down to personal preference.  It's your basic Chevy vs. Ford debate.

With that said let's get to the links.

First one, around the 1:10 mark the guy describes the ammo tested.  He had previously tested the ammo on the 16" gelatin block and knew overpenetration wasn't a concern.  So if he knows overpenetration isn't a concern why is he conducting an overpenetration test on ammo he already knows doesn't overpenetrate?  It's like testing whether I can breath under water when I already know I can't breath under water before I even conduct the damn test because I already conducted an underwater breathing test previously and learned that I couldn't breath under water.

Second one, I've already stated I'm not worried about overpenetration with my exterior brick walls if I used a .223/5.56 AR-15.  I'm more worried about overpenetration causing a through and through wound not killing the intruder in my home because an AR-15 may be overpowered for shooting someone in a room inside my house.  SSF made a valid argument that may not happen depending upon ammo selection.  A handgun with a slower muzzle velocity with the "right" ammo selection may be a better choice.  It's highly subjective.

The part I want to point out is the hyperlink to R.K. Taubert's article about .223 penetration.  I like reading primary sources, not some other guy's opinion of the primary source.  I wans't able to find an unedited version.  But, anyway . . .

Quote:Ballisticians and Forensic professionals familiar with gunshot injuries generally agree that high velocity projectiles of the .223 genre produce wounds in soft tissue out of proportion to their calibers, i.e. bullet diameter. This phenomenon is primarily attributed to the synergistic effects of temporary stretch cavity (as opposed to the relatively lower velocity stretching which typifies most pistol rounds) and bullet fragmentation on living tissue.

Distinguished forensic pathologist Dr. Martin L. Fackler, observed when he was conducting wound research for the U.S. Army several years ago ("Wounding Patterns of Military Rifles," International Defense Review, Volume 22, January, 1989), that in tissue simulants such as ballistic gelatin, , the 55-grain, M-193 military bullet lost stability, yawed (turned sideways) 90 degrees, flattened and broke at the cannelure (groove around the bullet into which the cartridge case is crimped) after penetrating about four to five inches. The forward portion of the bullet generally remained in one piece, accounting for 60% of its originally weight. The rear, or base portion of the bullet, broke into numerous fragments that may also penetrate tissue up to a depth of three inches. Dr. Fackler also noted that a relatively large stretch cavity also occurred, violently stretching and weakening tissue surrounding the primary wound channel and its effect was augmented by tissue perforation and further weakening by numerous fragments. An enlarged permanent cavity significantly larger than the bullet diameter resulted by severing and detaching tissue pieces. However, as the range increases, the degree of bullet fragmentation and temporary cavitation decreases because terminal velocity diminishes. At 100 meters, Fackler observed that the bullet, upon penetrating tissue, breaks at the cannelure, forming two large fragments. However, beyond 200 meters, it no longer looses its integrity, although flattening continues to somewhat occur out to 400 meters. 

In his study, Fackler remarked that in abdominal shots, "There will be increased tissue disruption (beyond the bullet diameter wound channel) from the synergistic effect of the temporary cavitation acting on tissue that has been weakened by bullet fragmentation. Instead of observing a hole consistent with the size of the bullet in hollow organs such as the intestines, we typically find a void left by missing tissue up to three inches in diameter." However, "unless a extremity (peripheral hit) is sufficiently thick like a thigh, or the bullet does not strike bone, the round may pass through an arm for instance, causing little damage from a puncture type wound." 

Regarding NATO’s 62-grain FMC M-855 (SS109) .223 caliber round Dr. Fackler observed that the bullet produces a wound profile similar to the M-193’s, particularly where abdominal or thigh wounds were involved. Other sources indicate this bullet, with a [steel] core penetrator, exhibits 10% greater fragmentation and retains its ability to fragment at slightly longer ranges than the 55-grain military bullet. [Keep in mind that the M-855 round, because of its steel core, has a length comparable to a 73-grain lead core bullet, and should be shot out of longer barrels (18+ inches) with tighter twists in order to retain good practical accuracy]

Hollow and soft point bullets in this caliber can be expected to upset and fragment much sooner and more consistently that full metal case (FMC) bullets. In light of this more consistent performance, Fackler recommends hollow points over "ball" ammunition for police use, providing the HP bullet penetrates deep enough to disrupt something vital. However, in his candid opinion the most effective round currently available for law enforcement operations is the 64-grain, Winchester-Western, pointed soft point, currently referred to as "Power Point". This bullet has a heavier jacket than those tested by the FBI, resists hyper-fragmentation, penetrates well and "expands like a .30 caliber rifle round." Subsequent FBI tests of this round fired from Colt’s 14.5-inch barreled Mk-IV carbine bore this out and bullet expansion was "impressive." 

Dr. Fackler also advised that the synergistic effects of fragmentation and high velocity temporary cavitation cannot be scientifically measured in gelatin because that medium is too elastic. More Accurate results can be obtained by examination of fresh animal tissue soon after it is shot. 

Most of the information coming from the pro AR-15 groups will underestimate or down play the wound characteristics.  But, one of the reasons the US military uses this weapon/ammo combo is because it produces wounds out of proportion to the calibre.  You can't appreciate the tissue destruction in a gelatin block. Plus since it weighs less than 7.62 ammo a soldier can carry more rounds at the same weight.  More rounds equals a higher volume of fire for a longer period of time.  These qualities along with high capacity magazines allows a soldier to gain fire superiority over the enemy.

To recap:

- designed for the military to kill the enemy
- produces wounds out of proportion to the calibre
- can carry more rounds per weight
- more rounds equals higher volume of fire for longer period of time = fire superiority

http://gun.laws.com/state-gun-laws/ohio-gun-laws

Anyone can buy an AR-15 at any gun show in Ohio without any sort of background check, license, permit, hunter safety course, or training of any kind.  Plus they don't have to keep records of the transactions.

[hollodero]

(04-04-2017, 02:55 PM)fredtoast Wrote: But having a giant retaining wall between your home and the road does not compensate for a small penis.

What does?

[oncemoreuntothejimbreech]

http://www.cs.amedd.army.mil/Portlet.aspx?ID=a99f565c-4029-4f74-b57a-2a6747614173

Military textbook includes ballistics. Pictures are NSFW.

[*michaelsean*]

(04-04-2017, 03:53 PM)hollodero Wrote: What does?

Ferrari

[oncemoreuntothejimbreech]

(04-04-2017, 03:00 PM)fredtoast Wrote: .223 is actually a small bullet.  So that might be true.

http://zonalandeducation.com/mstm/physics/mechanics/forces/newton/mightyFEqMA/mightyFEqMA.html

force = mass x acceleration

What the rounds lack in mass they make up for in accleration compared to 7.62.  Plus the tumbling affect rips the bullet into multiple fragments which helps transmit all of the kinectic energy over multiple wound tracks increasing the tissue destruction.  The more kinetic energy dumped from the bullet to the tissue increases the amount of tissue damage it causes.

[oncemoreuntothejimbreech]

(04-04-2017, 03:15 PM)michaelsean Wrote: That's what most of these military rifles shoot isn't it?

Probably, but they are available in multiple calibers.

[*michaelsean*]

(04-04-2017, 04:12 PM)oncemoreuntothejimbreech Wrote: Probably, but they are available in multiple calibers.

At the time we were speaking specifically of the potential to harm your neighbor.

[oncemoreuntothejimbreech]

(04-04-2017, 04:13 PM)michaelsean Wrote: At the time we were speaking specifically of the potential to harm your neighbor.

Again, I would say .223/5.56 is probably the most popular caliber, but I can't say that with certainty.

[*michaelsean*]

(04-04-2017, 04:18 PM)oncemoreuntothejimbreech Wrote: Again, I would say .223/5.56 is probably the most popular caliber, but I can't say that with certainty.

I quoted the wrong post.  Where you were talking about lethality (force=mass x acceleration) we were talking about threat to enter your neighbor's home.  

[hollodero]

(04-04-2017, 03:59 PM)michaelsean Wrote: Ferrari

What model do you drive?

[oncemoreuntothejimbreech]

(04-04-2017, 04:48 PM)michaelsean Wrote: I quoted the wrong post.  Where you were talking about lethality (force=mass x acceleration) we were talking about threat to enter your neighbor's home.  

That was more in response to the size of the bullet. A smaller bullet can be more lethal than a larger bullet depending upon the acceleration.

[fredtoast]

I don't think you all are using the F=ma formula correctly.  that does not really measure the force of impact with another object.  Instead it measures the amount of force needed to accelerate that mass to a certain speed.

For example a train traveling 100MPH but with zero acceleration is going to do a lot more damage to you than the same train going 5MPH but accelerating at a rate of 1 foot/second squared.

[oncemoreuntothejimbreech]

(04-04-2017, 05:54 PM)fredtoast Wrote: I don't think you all are using the F=ma formula correctly.  that does not really measure the force of impact with another object.  Instead it measures the amount of force needed to accelerate that mass to a certain speed.

For example a train traveling 100MPH but with zero acceleration is going to do a lot more damage to you than the same train going 5MPH but accelerating at a rate of 1 foot/second squared.

Talk to Fan in Kettering. He's the physicist.

Added: Look at the link for the military textbook. Then the chapter on ballistics. I gave you the wrong formula. Kinetic energy = mass x velocity squared/2. The velocity of the bullet has a greater affect on kinetic energy because it is squared and mass isn't

[Dill]

(04-03-2017, 11:47 PM)Sociopathicsteelerfan Wrote: I don't know, you'd have to ask them.  Oh wait, you're one of those people who makes sweeping judgments about people based on their appearance.

LOL bad me. Profiling doesn't work, right?   We'd have to ask them . . . .

[Sociopathicsteelerfan]

(04-04-2017, 08:31 PM)Dill Wrote: LOL bad me. Profiling doesn't work, right?   We'd have to ask them . . . .

Wait, so are you saying the profiling works?  Your initial statement would seem to indicate this.

[Dill]

(04-04-2017, 09:23 AM)fredtoast Wrote: If shooting at an intruder in your house could possibly kill your neighbors then it is a bad choice.

Depends on the neighbors.