Posted: 8/17/2004 9:25:09 AM EDT
I'm new to the site and this is my first post! hat
I'm considering the use against soft targets, soft targets behind plate glass and vehicle denial (damaging/penetrating a vehicles materials enough to stop a fleeing felon). This is a patrol cop question.
My general feel for both rounds is that the bonded will penetrate better, but will not tumble and fragment when entering a human target.
The weapon used to fire the round will either be the AR15A2 or Ar15A3 with a 1:7" twist
Any opinions on weapon selection?
Good bullet, mentioned here: www.ammo-oracle.com, which ya should read.
FWIW, w/ the 1/7 twist ya can shoot the 77grn. OTMs or SMKs or even the heavier than 62grn. "bonded" rounds available.
I've been using the Oracle as a source for a few months now. Probably because of that I've all but fallen in love with the M193 terminal ballistics.
Very many Departments and Fed agencies are using the 62 gr Fed Tac Bonded round. I would like to use M193. The problem is that I can't seem to find too much info on wound characteristics from the Bonded round.
I would like to compare apples to apples. I've seen the devistation that the M193 issues. If I could see (or if someone could refer me to a site or book) what a bonded round will do that would help.
The Tactical Bonded round has a smaller permanent wound channel than M193 - however it's a MUCH better round to use if you have to penetrate a barrier (such as auto glass) before striking the target. IIRC the Federal Bonded rounds are one of the very few .223 rounds that will penetrate auto glass and still meet IWBA critera (12-18" of penetration).
If your job requires you to deal with automobiles and carry a .223/5.56 carbine then I'd select the Tactical Bonded round over M193.
These bonded bullets work more like handgun HPs in that they cause their dammage by expanding like a mushroom (to .46") while punching a hole, they fragment very little.
From Dr. Robert's postings:
If I knew I was shooting through glass and such, I'd stick with the bonded round. And even though mr.wilson is right, I think the bthp's wouldn't be very good at all through glass. Although I have no reference besides the fact that I know the jackets are thinner. So it would only make sense if the bonded ones are better through glass and barriers, that the thinnest jacket ones would probably be the worst. Please someone shooting this thinking down if it is wrong though. (directed to only the experts)
Thanks for the input thus far everyone.
Here's what I'm thinking when I said shooting through glass and vehicle denial:
This is what I am assuming to be typical "rules of engagement"
We're probably not going to be firing on moving vehicles. A successful kill would most likely result in a driverless vehicle... Generally not a good situation. So probably no roadblocks and shots through windshields. If it ever comes to that we could use Shotguns and slugs that would easily get through the windshield and into the perpetrators "mind".
I'm thinking of situations where we have a shooting "in progress". This is a typical 'angry worker returns to the office' shooting or 'postman gone man' type. Or situations where armed suspects are leaving a business or bank and are heading to a car.
The shooting through glass would probably be limited to placing several shots through the side glass of a car as the suspects are attempting to enter. Most likely we would be firing on the suspects prior to their arrival at the vehicle. And even if they did successfully enter the car a couple of shots into the windshield would send the interior layer of the windshield into the face of the driver/passenger. It's difficult to drive with glass in your eyes.
Patrol is looking to suppress the suspects. The whores of the court don't ever want us to say "Kill" because that implies malace, but for all intents and purposes suppress means prevent further action. To that ends, we are looking to kill, wound to the point of making the suspect unable to continue, wound to the point of making the suspect unwilling to continue, or scare the suspect to the point of being unwilling to continue.
A perfect bullet (my opinion) would not penetrate interior or exterior walls, it would penetrate vehicle materials and explode when it entered into a human target, and it would force the suspect to make a dying declaration, "I'm an idiot. This was the biggest mistake of my life. I deserve to die."
All of the claims of the blended metal round... well, except for the dying words thing. he
The bonded is typical of hunting rounds. It gives very consistant expansion to .45" and a linear wound channel. It's great because it doesn't fragment and maximizes the meat on the table.
I don't want to eat my target. I just want to bury it! him
Is anyone going to defend the M193?
Does anyone agree with my line of thinking?
Is the bonded round really more useful?
These are the type of situations where the bonded glass would be the better choice.
also this is bad thinking: "a couple of shots into the windshield would send the interior layer of the windshield into the face of the driver/passenger. It's difficult to drive with glass in your eyes."
And if he happens to be wearing glasses or looking down?
Don't depend on secondary missles to do your job. Use the right ammo, place the shot correctly and stop the threat.
Ah if it were only possible.
and I'm selling this snake-oil that will cure all your ills and cancer too!
It's only devestating if you hit something thick enough - its a minor wound in other places. The OTMs provide much better terminal ballistics.
The bonded round will do that fine - IF you put the round where it belongs - shot placement - shot placement - shot placement.
The bonded rounds will do that if you have to shoot through glass - M193 wont.
For your situation - where you indicate you might have to shoot through glass - yes it is more useful.
I know you have asked for a preference between M193 and the 62gr bonded bullet, but I really must recommend the Hornady TAP 75gr for carry.
It is much more devastating than the M193, and bullet deflection and weight retention through auto glass is "best in class." Bushmaster used to have data comparing the various TAP loads through glass in the Law Enforcement section of their web site. I have also practiced shooting the 75gr TAP through front windshield glass at a target and it was quite effective at reaching the target with minimal deflection.
Your 1:7 twist guns are perfect for this round, BTW. And the box says "Police" on it - what more could you ask?
Yes the 75gr has minimal deflection after going through glass (and is a much more devasting round than either M913 or the bonded rounds)
However it doesn't meet the penetration requirements. If you're lucky and get an 'optimal' shot it will work. But in one of the various 'less than optimal' cases the round won't make it to the vitals.
I've read just the opposite - greater penetration than M193.
Tat or Brou - any comments?
Yes greater penetration than M193 after passing through glass - however it's penetraion is not up to FBI or IWBA minium standards.
I have the Hornady Tap report in front of me and it shows only 8" of penetration after passing through automotive glass; with the max cavity at only 3" of penetration.
I understand that the bonded round will penetrate barriers well but I'm on a tight wire here. What about the bonded's capability to burn through an exterior wall? That is a real hazard in a city environment.
I'd rather hand the guys some ammo and say, "This stuff will kill bad guys dead, and not punch through houses. But if you need to get inside a car use your shotgun and slugs."
Than say, "This stuff is hot. It will penetrate deep. Watch your backstop. Oh, and non brick houses aren't considered a sufficient backstop for this round."
Problem: if I recommend a round that is too effective at penetrating barriers, my guys will not be able to engage suspects as often (or if they do they're putting everyone at risk in the event of a missed target). The whole reason I'm looking at 5.56 is it's reduced barrier penetration characteristic.
As I said, this isn't for Snipers or SWAT. We need to contain threats inside buildings or kill 'em quick outside buildings. If they are contained then we have the time to get SWAT and the Snipers on scene for the trick shots.
And again, we're not shooting at moving cars. The limited circumstances (that I can dream up right now... which will certainly be out-done by reality) when we would be firing through glass is when an armed perpetrator is trying to get into a car and start it. Given that situation It's open season. Most other circumstances would involve perpetrators in the open, possibly wearing body armor.
Forest what's an "OTM" ?
gaijin I'm guessing "TAP" stands for tactical armor piercing ?
I appreciate all of the help so far. You guys are great. Most of the people I discuss this with reply with a blank stare.
Oh, and in my experience if it says "Police" on the box, that doesn't mean it works...
It just means it's over-priced.
If you have the shotgun option for your guys - have them use that and give them the 75gr TAP rounds for the AR-15s.
I should point out you also need to say this for their handgun rounds and any buckshot or slugs you will be using also...
As long as one of your officers has a shotgun with slugs you'll be ok.
Definately that is a 5.56 shot (you've seen the LA bankrobber videos showing how ineffective shotguns are against people in body armor).
The shorthand method of saying "Open Tip Match". They used to call them HPBT - Hollow Point Boat Tails - but hollow points imply the round will expand (like a handgun hollowpoint). Match rounds have an open tip due to the manufacturing process - it is NOT intended to expand. Thus the term OTM was created to differentiate the two.
Try "Tactical Application Police". The 75gr is the only TAP round that meets FBI & IWBA criteria for penetration. The 75gr version uses their 75gr Heavy Match OTM bullet - the other two loading use plastic tipped varmint bullets.
Forest has it right!
OK, OK, OK!
I just let go of my military comfort zone and accepted your advice. It was good advice.
I'm going to go with the 62 grain tactical bonded round. The round is just more useful under more conditions. A good point was made that I had overlooked, the slugs and .40 cal rounds we fire, still penetrate deeper than any 5.56 rounds that I've considered.
And for training we'll use the M855 62 grain FMJ.
The Federal Tactical Bonded 62 grain round was clocked at 3056 f/s from a 14.5 inch barrel. Does anyone have the speed of a M855 from a similiar barrel?
M855 from an M4 - 2970fps @ 78'
I knew great minds worked alike
Thank you for the response!
Forgive me if I am truly wrong, and only you will know as the net is a dangerously anonymous place at times.
You language that hints at L.E. use is in no way indicitive of being L.E. in the State of Michigan or any other state or Province so I have my doubts.
The limitations on M193 and M885 ball against barriers is well known to almost all agencys that are open resources to L.E.
The Limitations of the Fed tactical and other narrow purpose loadings that are avaialble, are also commonly known to L.E.
I ain't a Mod, and I am really just a nobody, but i know what I know, and you ain't a Cop.
Again, if I am wrong, apologies.
But in these times, I question your intent based on the obvious.
Brou, Tat, and the other mods........
Apologies for any indisgression.
I wouldn't post this if I did not smell a Rat.
The only way an LEO is going to know any of the ballistics info is if they read this site or others or have been on a very well run ammo selection committee. Most officers know Lethal Threat - Front Sight-Center Mass-Squeeze- Repeat and that is probably good enough if they actually do it . Most Officers (>50%) Use a Department issued weapon with Department issued ammo and Know nothing about ballistics outside of 9mm-light and fast .45-big and slow .40 Cal - Mother Bear says it's just right. If you read the Ammo Oracle on this site and understand it you will know more about .223/5.56 ballistics than most of the LE/Military/Merc/Hunting Guide Armorers/Outfitter/Gunstore Owners/Range Officers/Blended Metal Shills/Competition Shooters out there.
To say that someone is not an LEO because he He didn't get the lastest FBI APB on the pros and cons of SAAMI Spec .223 Federal Tactical BJSP And HP vs Nato Spec 5.56 FMJ for patrol rifles is a little silly.
The real reason we know he's not an LEO is because he used a in his intro post and did not ask how well the Federal Tactical Bonded Jacketed Hollowpoint in 62gr worked on fido after passing thru window glass.
as this is a forum you are entitled to join the discussion. I'm not going to be baited into a defense regardless of what you may post.
Further, there have been numerous tests on M193 and M855. The true ballistic nature of the M193 round wasn't fully described until the mid 80's even though it had been in use since the 1960's. There are differing opinions for tactical applications on almost every round available.
Let me do a little analyzing...
English isn't your first language.
You must be an immigrant to MI or you are actually living outside the U.S. and Canada.
You joined the site in 2002 and have less than 500 posts to date.
You must read alot of these posts but not join in nor offer any valid input.
You may not agree with the 9-11 attack but you "understand" why they did it...
If you smell a rat maybe you should take a shower.
And if I am wrong... my sincerest apologies.
Where are you getting this info on the 75 gr TAP?
The only source I've read on it shows it performed marginally against barriers with Glass being a deal breaker.
Lots of guys seem to love this round but I haven't seen any documentation to substantiate this loyalty.
As you can see the lighter Federal Bonded doesn't do much damage and doesn't fragment. Heavier federal bonded is similar. The 55 grain is one of the only .223 rounds, however, that will penetrate gel very well after encounters with windscreen (front window) autoglass at angles to the angle of attack. As a CQB load it is quite poor.
You aren't going to get "vehicle denial" out of any .223 rounds except maybe by shooting at the tires. You aren't going to do very well through the front windshield either.
Front windscreens are tough barriers. I don't recommend relying on shots through them for stopping unless you have no other alternative. Side windshields are MUCH weaker and present much less of a barrier.
I would NOT go making general ammo decisions based on their performance in front windscreen encounters. There are, I expect, only rare instances where an encounter will require this sort of engagement anyhow.
Heavier 5.56/.223 rounds will preform "soso" through windscreens and will get you very good terminal performance elsewhere. You will want to consider the 69 grain OTM rounds, 68 grain OTM rounds, 77 grain nosler rounds (not so much the SMK rounds in 77) and the 75 grain Hornady rounds (TAP 75 grain).
M193 is a fine round as well but there are better out there. If the choice is between M193 and Bonded 62 grain I go with M193 EVERY time, even against people in cars. Car doors and side windows are very weak. Concentrate there, not at the best armor (the front windscreen/hood area).
Again, in summary: No .223 is ideal for autoglass while tactical bonded in 55 and 62 grain is "ok." I would give up the autoglass specification as a determiner for your .223 selection.
Personally, I'd go with 75 grain TAP. Its OUTSTANDING against non protected targets, doesn't over penetrate interior walls and does reasonably well against front windscreen glass. For the record it DOES meet 12" penetration against both heavily clothed and IIIA armor clad gel. (!!)
I would consider a windshield shot to be a last resort. Similiar to one of those WW2 encounters where a sub would give a destroyer a "bow" shot. But from what I've seen the 62 gr Bonded gives the most consistant penetration of barriers and expansion once into a soft target. If I can find credible data to support the 75 gr TAP rounds performance I'd consider it.
And Heavy Clothing doesn't seem to be a huge problem for most rounds. The data I'm seeing is that windshields and drywall seem to give 5.56 rounds the most trouble.
I'm sure the heavier 75grain rounds would have less deflection upon encountering a windshield but the penetration numbers seem to be on the light side, not meeting FBI or IWBA standards.
I'm Sorry tatjana, you're right. I overstated what you said about the 75 gr TAP. The info I've seen on the 75 gr TAP shows it to be rather typical of other 5.56 ammo. I'm also guessing that the 75 gr would require a faster twist rate than 1:9 ?
I can think of one situation where cops would have to shoot through barriers... Stopping a fleeing felon.
Perp performs a violent felony or attempted one and he's heading for a car. We would need to penetrate through typical vehicle materials to stop him.
or a perp is involved in a shoot out and attempts to enter a building to elude capture. I'd want to be capable of taking a shot through the door glass and into the suspect. I've been considering the balancing act of barrier penetration vs. public safety. The best argument thus far has been the fact that 12 ga slugs and the current issue 40 cal ammo shows deeper penetration than either the M193 or the Fed Tac Bonded 62 gr rounds.
I agree these are very limited situations but active scenes are typically very fluid and the weapon/ammo combination must be suited for a changing environment.
It drips of professionalism and all that.
The language that tipped me off still eludes you.
In public, no cop or member of any agency Private or public would use some of the key words you have used.
And for the Record. No I am not an immigrant. My people have been residents of Michigan since long before the whiteman arrived . On Sept. 11th 2001 I lost 3 friends, since then I have lost 5 others in Iraq and in the Stan.
Cyberspace allows for being anonymous and distant.
It also allows for posing as something you are not.
PM me if you will, and I will confirm, and back off.
Otherwise I wonder why you are interested in " Successfull Kills" of vehicle operators when it is well known that the only way to disable a vehicle threat in public, involves more Tactics than using rifle fire.
In short. Your reply has absolutely reinforced my Precognition that you are not L.E. and for whatever reason, you have chosen to pose as one along with the question asked of the good folks here.
I can't get the reply thing to work in this forum...
<Legal quiz: When can a law enforcement officer use deadly force to stop a fleeing felon?>
Tennessee v. Garner
ANY citizen can use deadly force in an "imminent threat" situation. Police have the obligation to apprehend violent felons to safeguard the public. The key word being "violent". If a perp kills or attempts to kill or seriously injures a victim and it appears the perp is going to elude capture Police can declare "open season" on the perp. He has demonstrated that he is a threat to society and the courts recognize that a danger exists if he is allowed to remain at large. This decision was upheld by the U.S. Supreme Court and it's the model for deadly force policies nationwide.
Here's another example: A guy is suspected of being an axe murder. You (as a cop) see him hacking away at some poor soul. The victim drops dead (or dying) as you draw your weapon. You identify yourself and order the perp to not move. He drops the Axe and runs to a vehicle. You're car is 100 yards behind you. If you let him get into the car he's going to enter the freeway and be out of the area in minutes. As he's running to the car you notice that the backstop is a brickwall. He dropped the axe and is unarmed. His back is your only target as he runs away from you. You can't catch him and he's going to be out of the area in minutes. Shoot or Don't Shoot.
Policy based on Tennesse Garner says... Take the shot. Even though he's unarmed and will take a bullet in the back it's a good shoot. He could easily buy another axe and find another victim if allowed to escape. Maybe this will shut 'S-28' up
<Just about everywhere I know of you cannot unless that fleeing felon presents imminent risk of death or serious bodily harm to someone. (e.g., is about to run you down with their car). Shooting an otherwise unarmed fleeing felon driving a car (pretty hard for him to be brandishing a weapon while driving, but I imagine he could be) just isn't a legal use of deadly force anywhere I am aware of.>
<This amounts to "well all the other ammo we use is super deadly to potential bystanders, why should we care about our .223." How comfortable are you with this logic, because I am not.>
My point was: ANY 5.56 round I choose will still be less hazardous to the public than the current ammo used in the SG or the .40 cal.
<There is no such animal. The trade off of penetration and wounding potential makes it an "either or" situation.>
<Bonded rounds like the Federal 55 and 62 grain just don't do enough tissue damage. You are therefore reducing lethality in favor of a bullet that covers 99% of your potential encounters "so-so" instead of 95% of your encounters "outstandingly." I find that unacceptable. But, your philisophy on terminal performance might just be different than mine.>
I've talked to guys that are fielding M855 and others that are using Bonded 62 gr. Both think the world of their choice. The guy fielding the Bonded rounds actually had several positive incidents backing up his choice. I was initially thinking that using the M193 would be great because of its wound profile. Putting a 10 cm cavity in the torso of an active shooter would take the fight right out of him. But the M193 is less consistant than the Federal Bonded Round (FBR). The tests I've seen on the FBR have a very small standard deviation. The FBR meets the FBI standards on all barrier tests. I just don't want to recommend a round and have someone shooting multiple times at a target behind light cover with negative results. I know how I would feel if I were in a gunfight and failed to drop someone I could see that took cover behind glass. Even though the FBR is going to create less damage than the M193 or M855 it's still going to penetrated deep into the target and expand to .45 inch, and "6 of one, half-dozen of the other" a downed suspect is a downed suspect. The FBR is just more useful in more situations than the M193.
I also ran across a paper written by Fackler, posted on another site, where he recommended LEO's to use JHP's. I don't have access to the full paper (or book).
First off, its "The Crusader"
Gosh, You're right. You caught me! I'm a government spook. I'm from the rogue nation of Etriea. We have just aquired some 5.56 rifles and my task was to infiltrate the AR15 website and aquire intel on the best ammo to use.
Exactly what kind of SECRET information do you think I'm going to get regarding 5.56 ammunition?
Again let me take the time to thank you for adding to the ON TOPIC discussion. Maybe you should go on a vision quest to get your head together. Because that indian inutition your trying to use here is waaaaay off bud.
I have to agree with some of the points made here. When choosing something for a general purpose, yet buying for only 1 specific purpose, you may lose more in many ways than you gain. For a patrol carbine, I think I would want the best anti-personnel round I could get my hands on. Sure, the OTM rounds may not be as good as the bonded SP's for that one purpose of barrier penetration. But in nearly every other way they are superior. So you go with what works best in the widest variety of circumstances. If penetrating barriers is your only concern, then you have the wrong caliber to start with.
You'd better work on more articulation then just a fleeing violent felon. Imminent may have various interpretations depending on what part of the country you're in. Be careful of what you post. It may end up in court. Stick to AR topics.
Thanks Charging Handle. I am still looking for data on the 75 gr OTM round. I can find all sorts of stuff on M193 and M855, but can't find anything on the wound profile of the OTM.
The best info and wound ballistics I've seen have been between the M193 and 62gr Bonded. Until I can find something with hard-core credibility to back it up I've got to stick with one of those. Don't get me wrong, I respect the your opinion and others regarding the OTM, but I have to defend this myself... and I can't very well say, "It's good because the guys in the forum said so."
Thanks but, Nope.
I'm using the same language from the court decisions. I stick by everything I've said above. And understand this... if you ever land in court regarding a shooting you will be challenged to justify why you believed that the threat against your life was imminent. And if it's a fleeing felon situation the cop will have to justify why he believed the guy was about to successfully escape, and why he posed a threat to society if allowed to escape.
And finally, yes I'd like to stick to AR topics, particularly Ammunition as it relates to the M193, Federal Bonded 62 gr and 75 gr OTM in this thread.
You have several options.
1) What are you looking for? From what Length barrel? I have data on the wound profile if you want it .
2) Contact Hornady they can send you a copy of their test results for all the TAP ammo
3) Contact the IWBA and order back issues of their Journal. There should be info on it.
4) Contact the FBI and ask for their data (they share with LEOs).
We're going to be using 16 inch barrels with a 1:9 Twist.
The FBI only has penetration data. I want to know how the bullet behaves once it's penetrated into the gelatin. It looks like it fragments to some degree but there is no detailed description as in Facklers examination of the M193 and M855.
Thanks I'll try the IWBA too.
Just look at www.ammo-oracle.com. There should be more than adequate info contained within to convince you that the 75 gr OTM is superior to M193. But being you have a 1/9 twist, you may or may not have to drop to a lighter bullet weight. Some people have no problem with stabilizing the heavier bullets in 1/9 twist, while others do. So if your accuracy with the 75's really sucks, you can also get 68 gr versions from Black Hills that also perform well. They aren't quite as good as the 75's, but they are still superior to M193 as far as terminal ballistics go.
And if you are still not convinced, go here and check out the "terminal effects forum":
DocGKR, the terminal effects moderator there, is one of the foremost terminal ballistics experts in the nation. Dr. Roberts likes the 75's very well and if you read through the posts there, you'll see why. But a word of advice, use the search function before posting. They tend to not like repeat questions over and over there.
Ain't no secret involved.
Get on the Horn to MSP or Detroit SRT and ask them how their SWAT guys are handling the situation. It is actually very simple and easy to train on.
Granted, there will be some red tape and delays getting ahold of the right people, but the answers you get will have been proven as justifiable in court ,and more easily sold to the brass when you present the change in purchasing and in training.
Setting up a Demo with Federal, for Dog and pony purposes is easily done. Just contact their L.E. division and ask. If there enough bodies and interest( Contact your mutual support agencys and have them sign on) they will bring the ammo and Gel, and do the demo and add credibility to justifying the transition.
You also might want to touch base with the PA in the process as well.
The liability loop being reduced and supported by him/her, will be another good selling point.
If you are a Cop, then like I said I will apologize.
BTW, since I mentioned the alternatives to the 75 grainers should they not work in your 1/9 twist, here is some data regarding those alternatives:
.223 Black Hills 68 gr BTHP Match
velocity: 2615 fps
temporary cavity max diamater: 9.0cm
recovered diameter: 0.39"
recovered weight: 31.5 gr
.223 Federal 69 gr BTHP Match
velocity: 2646 fps
temporary cavity max diameter: 10.0cm
recovered diameter: 0.40"
recovered weight: 27.5 gr
.223 Winchester 69 gr BTHP Match
velocity: 2758 fps
temporary cavity max diameter: 8.5cm
recovered diameter: 0.36"
recovered weight: 17.5 gr
The 75's will even be a bit better when you locate that data at the above mentioned sources. But the alternatives aren't bad at all should you have to go that route. Out of the above 3, my favorite is the 68.
The Hornady report gives a complete wound profile report - and they ran their 16" test with a Bushmaster 1:9 twist barrel. Everything you need to know - just contact them.
OK S-28, Please pardon my sarcasm. We probably just got off on the wrong foot.
I have talked to MSP training and they're using the 62 gr Bonded with good results. That's why I was considering that round. FBI also rates the bonded highly, but only tests barrier penetration and gives little info on "gel action". They don't go into how gel was deformed. Just depth of penetration. So I'm left a little in the dark with them.
I talked to a range officer from another local PD about his choice of M855. That's how I found the Oracle and another site that published Fackler articles. I was truly surprised at the damage of that little bullet. Once I read more about the round I decided that the M193 might be a slightly better choice than the M855.
Now given the two rounds I needed to determine what would suit a patol officer best. Lots of guys will spout off about some SWAT round or some Sniper round. Patrol has a different mission with different requirements. Patrol will most likely deploy the rifles at established hostile scenes. This means that the officer will have a choice of cover and distance before most engagements. Patrol (like MSP) will make felony vehicle stops which may require a shot through auto glass. I'm also taking into consideration the possibility of penetrating the backstop. Wood frame homes are a concern here.
It comes down to this for me. If there is a shoot out involving rifle fire we need to subdue the perpetrator as quickly as possible. The fewer shots fired, the safer the public will be. If I provide a round that will not effectively penetrate glass then the fight may rage on placing more people at risk. Much like LAPD firing 9mm into the Hollywood bank robbers level 3 vests.
I would love to recommend a round that will fragment and give that baseball size cavity in the perp's gut. But if it's not going to get through light cover (and I have to consider auto glass light cover) then it's not going to be useful to us.
So ... which is it?
That test is pretty helpful. Both rounds appear to do a real number on the gel.
I have no personal experience with ballistic gelatin. From looking at the gel I'm guessing all of the darkened areas are permanent crush cavities?
I noticed that the published photos were the "highest performance" examples of the test. Was there a wide gap between the best and worst example with either bullet? Did any round fail to fragment?
Sorry about the confusion.
I'm writing a proposal for purchase and deployment of rifles and ammuniton. The weapon I'm recommending is the AR15A3, 16 inch barrel with a 1:9 twist. The weapon choice was based on info from the Oracle and practical needs. The twist was directly from the oracle. At that point I really wasn't focusing on the heavier rounds... 69 gr and above. I was planning on using the M193 and figured the faster twist would allow a change in ammo at a later date without requiring a barrel change.
1:7 is the faster twist.
You can shoot all effective bullet weights from 55gr to 80gr(or more?) in the 1:7 twist barrel.
Why not spec the 1:7 barrel?
Am I violating any AR15.com fourm policy?
I'm asking questions to get input from people. And I'm hoping for better answers than "yes", "no", "this is the best" and "this is junk". A short justification of an answer is always helpful.
When I'm speaking about punching through autoglass... I want the capability to make it through the thickest stuff on a car 6mm laminated windshields at angles. I've stated that several times.
Sorry I don't know your background or what testing you've performed in the past. So asking for justification on a round recommendation seems reasonable.