An Accurate AR is... an Accurate AR...

[98Z5V]

Gas gun shiit.  If you have an accurate gun, well then, you have an accurate gun.  Period.  It'll do magic for you, to the extent of the projectile design, AND your intended purpose for the gun.  I'll get into that in a minute, after the vid.  What triggered me on this subject was this vid I stumbled upon...  right here...

 

Just like real life, IMHO, length does matter...     But it's to a certain extent, and for an intended purpose. 

Banging steel, running a cartridge to it's MAX range from a SMALL barrel...  Well, an accurate gun is an accurate gun.  Period, end of story, dial your dope and run that thing out there to it's supersonic max range - and it's still gonna be that same accurate gun.  Run that fukker PAST it's supersonic range, get into the transonic tumble, and all that - and it's on you.  Bullet (projectile) selection is the only thing that will "extend you" a little bit past that.  Once you're subsonic on your projectile, the thing has a glide ratio of a brick...  and it drops like a brick.  It's all luck, witchcraft, voodoo, and black magic - from that distance on... 

I'll get more into this, and I'm making if 5.56 specific for examples, just because that's the cartridge that I've done the most research on, and there's the most data out there.  As far as barrel length goes, velocity per inch of barrel, on 5.56, there's a pretty graduated drop from a 20" barrel down to the 11.5" barrel - you can -retty much call that "per inch" in velocity drop.  You go down to a 10.5 " barrel from the 11.5" barrel, and there's a MASSIVE drop in muzzle velocity.  Just between those two lengths. 

One more tidbit.  55gr 5.56, and what makes it work - fragmentation of the projectile.  THAT is what makes the 5.56 cartridge what it is.  Frag.  Upon impact.  I ran the numbers a really long time ago, and I'll try to find them, but if you run the 11.5" barrel, loaded down with 55gr M193 ammo, your max frag distance is 175 yards.  After that distance, you're just shooting an icepick at someone, that's gonna leave a neat, small, little hole all the way through, and the projectile will not frag in a meat-and-bone-based body.  Deer, elk, whatever you're hunting with it.  No matter how many legs it has... 

I'll get more into this, but watch that vid above.  It's pretty good.  A team of dudes from 5th SFG(A) showed up to a DMR course with their Mk18s, with 10.3" barrels.  They crushed it to the 600 yard distance of the DMR course.  I've personally watched @JBMatt in matches, shoot 700-ish yard targets with his 13.9" barrel.  Just last weekend, he dialed up his dope for the 780 yard oxy tank buried in the hills, and hit it, right after he dialed up his dope for the 712 yard 12" plate, and hit that one.  Short guns aren't magic - but they need to be accurate guns, to start with.  And the hand load needs to be there to make that happen.  Accurate guns are just accurate guns. 

We'll get into this further.  Please discuss. 

[98Z5V]

Here's kind of a "follow-up" and a way to drive the point home a little.  Good vids.

 

 

Edited June 4, 2023 by 98Z5V

[Cunuckgaucho]

Thanks,lots of info to ponder and potentially use once my ARs are no longer under house arrest 

[98Z5V]

Thank you, brother.  I guess I wasn't clear initially, the more I think about it, with the layout of this thread.  This is about the use of the (whatever) cartridge for the two disciplines, and something to think about.  Target shooting at paper and steel, then using the cartridge for hunting.  Two completely different animals, those two.  Different games. 

Target shooting - if it's an accurate gun, you'll hit your target at whatever distance, if you have the math, know the math.  That's easy, and really just a calculation for drop, wind reading and (#1) target range estimation, if it's an unknown distance target.  That's just all a math problem.  For that, I don't care if the projectile fragments inside tissue, because it just needs to leave a mark on steel, or a hole in paper...

For the other part, and again, only using 5.56 as the example here, just based on the sheer amount of data on hunting people with 5.56 guns ( Dr. Gary K Roberts, and all his tremendous data on combat applications), hunting comes down to MPBR - Maximum Point Blank Range - and it comes down to the frag distance of the specific projectile.  The shorter the barrel, the less muzzle velocity, the less distance you get for that frag range, barring specialty ammo.  That's the only thing that makes these gas guns work, for hunting.  Long Range Hunting is a different game, altogether, but I'm sure we'll get into that over time here. 

Here's an example of Dr Roberts work, and his background:

https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2008/Intl/Roberts.pdf

[98Z5V]

Here's a metric shiit-ton of data on 5.56 fragmentation, speeds, and different projectiles.  The same thing applies to any cartridge, no matter what the caliber, and that's based on projectile selection for the intended purpose.

http://www.mlefiaa.org/files/ERPR/Terminal_Ballistic_Performance.pdf

 

***NOTE - notice in that article that they start talking about the Barnes 70 TSX for the 5.56 loads.  That is one badass projectile for a 5.56 gas gun.  It beats the Hornady 75gr BPBT and 77gr Sierra OTM projectiles for terminal performance, long term and short term, it's a smidge lighter then both so it can be driven faster, given chamber pressure max for the platform, and since it's solid copper, it's longer than both of those projectiles listed above, which gives it a slightly better BC. 

Militarily, it was loaded, and used, and had a brown tip color, to distinguish it from other loaded ammo.  It was the "Optimized Brown Tip" ammo, in military circles.  That's something that can be researched, but it's gonna lead you down a rabbit hole, I'm telling you now... 

[98Z5V]

I'm trying to find the reference right now, but the Nosler Accubond Long Range (ABLR) projectiles have been listed before as fragmenting down to 1700 fps.  What I remember about that is the 6.5mm 129gr ABLR - usable in Grendel, for hunting.  That's SLOW, for a projectile to fragment - but that's why it's their "Long Range" design in the first place.  They figured that shiit out, somehow. 

[Turd Furgeson]

On 6/2/2023 at 11:08 PM, 98Z5V said:

Gas gun shiit.  If you have an accurate gun, well then, you have an accurate gun.  Period.  It'll do magic for you, to the extent of the projectile design, AND your intended purpose for the gun.  I'll get into that in a minute, after the vid.  What triggered me on this subject was this vid I stumbled upon...  right here...

 

Just like real life, IMHO, length does matter...     But it's to a certain extent, and for an intended purpose. 

Banging steel, running a cartridge to it's MAX range from a SMALL barrel...  Well, an accurate gun is an accurate gun.  Period, end of story, dial your dope and run that thing out there to it's supersonic max range - and it's still gonna be that same accurate gun.  Run that fukker PAST it's supersonic range, get into the transonic tumble, and all that - and it's on you.  Bullet (projectile) selection is the only thing that will "extend you" a little bit past that.  Once you're subsonic on your projectile, the thing has a glide ratio of a brick...  and it drops like a brick.  It's all luck, witchcraft, voodoo, and black magic - from that distance on... 

I'll get more into this, and I'm making if 5.56 specific for examples, just because that's the cartridge that I've done the most research on, and there's the most data out there.  As far as barrel length goes, velocity per inch of barrel, on 5.56, there's a pretty graduated drop from a 20" barrel down to the 11.5" barrel - you can -retty much call that "per inch" in velocity drop.  You go down to a 10.5 " barrel from the 11.5" barrel, and there's a MASSIVE drop in muzzle velocity.  Just between those two lengths. 

One more tidbit.  55gr 5.56, and what makes it work - fragmentation of the projectile.  THAT is what makes the 5.56 cartridge what it is.  Frag.  Upon impact.  I ran the numbers a really long time ago, and I'll try to find them, but if you run the 11.5" barrel, loaded down with 55gr M193 ammo, your max frag distance is 175 yards.  After that distance, you're just shooting an icepick at someone, that's gonna leave a neat, small, little hole all the way through, and the projectile will not frag in a meat-and-bone-based body.  Deer, elk, whatever you're hunting with it.  No matter how many legs it has... 

I'll get more into this, but watch that vid above.  It's pretty good.  A team of dudes from 5th SFG(A) showed up to a DMR course with their Mk18s, with 10.3" barrels.  They crushed it to the 600 yard distance of the DMR course.  I've personally watched @JBMatt in matches, shoot 700-ish yard targets with his 13.9" barrel.  Just last weekend, he dialed up his dope for the 780 yard oxy tank buried in the hills, and hit it, right after he dialed up his dope for the 712 yard 12" plate, and hit that one.  Short guns aren't magic - but they need to be accurate guns, to start with.  And the hand load needs to be there to make that happen.  Accurate guns are just accurate guns. 

We'll get into this further.  Please discuss. 

Good one.

[Turd Furgeson]

1 hour ago, 98Z5V said:

Thank you, brother.  I guess I wasn't clear initially, the more I think about it, with the layout of this thread.  This is about the use of the (whatever) cartridge for the two disciplines, and something to think about.  Target shooting at paper and steel, then using the cartridge for hunting.  Two completely different animals, those two.  Different games. 

Target shooting - if it's an accurate gun, you'll hit your target at whatever distance, if you have the math, know the math.  That's easy, and really just a calculation for drop, wind reading and (#1) target range estimation, if it's an unknown distance target.  That's just all a math problem.  For that, I don't care if the projectile fragments inside tissue, because it just needs to leave a mark on steel, or a hole in paper...

For the other part, and again, only using 5.56 as the example here, just based on the sheer amount of data on hunting people with 5.56 guns ( Dr. Gary K Roberts, and all his tremendous data on combat applications), hunting comes down to MPBR - Maximum Point Blank Range - and it comes down to the frag distance of the specific projectile.  The shorter the barrel, the less muzzle velocity, the less distance you get for that frag range, barring specialty ammo.  That's the only thing that makes these gas guns work, for hunting.  Long Range Hunting is a different game, altogether, but I'm sure we'll get into that over time here. 

Here's an example of Dr Roberts work, and his background:

https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2008/Intl/Roberts.pdf

Wow... dude knows his stuff... time for a 6.8mm.

[98Z5V]

1 hour ago, Turd Furgeson said:

Wow... dude knows his stuff... time for a 6.8mm.

Doesn't matter what the cartridge is.  .243 Win, .260 Rem or a 6.5 Creedmoor, 7mm-08, .308 Win.  Or more, .338 Fed, .358 Win.  Whatever, anything in between.

Steel and paper, or hunting, those two things matter, and only because of the projectile selection, and the intended purpose.  That's what I'm trying to get at.  All the 5.56 stuff is just the vehicle for the information, simply because there's so much more information out there now on it, after 2 straight decades of war with it. 

For hunting, if you can keep the cartridge of choice inside your MPBR circle, then you only have to aim once, if that thing is within your MPBR.  You'll get it, if the shot is true.  For distances beyond that - then we'll be doing a math problem, and solving it quick.  If that's a "longer range" hunting issue, outside your MPBR, then the projectile selection needs to be up to the task for the job.  If it's steel or paper - it just needs to be an accurate gun. 

Lots of things to consider, depending on what you're doing.  That's why there always the questions to people here, trying to figure out their gun.  "What's the indended purpose, and max range that you'll be shooting at?"  We ask that of people all the time, when they're talking about some crazy build here. 

[98Z5V]

Here's a more graphic example of what I'm trying to get across - I'm not doing well getting the information out, like I intended.

I can kill ALOT of squirrels and rabbits with a .22LR rifle.  I can also turn both of those critters into a pink mist with a .204 Ruger projectile going pretty close to 4000 fps.  If I shoot them with a .22LR, there's something there that I can stew up, if that's the goal.  If I shoot them with that .204 Ruger hot load, I can't even pick up pieces with q-tips and tweezers...   Comes down to the intended purpose, again. 

I switched out my long distance .308 Win load from the Hornady 178gr HPBT (used that for many, many years) to the Hornady 178gr ELD-X projectile.  There were two reasons for that.  #1, the 178 ELD-X BC is the best .308 Win-type projectile that Hornady has ever developed, highest BC in all the common .308 Win based projectiles that will fit into a 2.800" COL, magazine length for gas guns.  So, it's gonna be the most accurate projectile to put through a .308 Win gas gun.  #2, it's the ELD-X projectile - the expanding projectile.  I win, both ways, because I've got the best hunting load that I could ever develop for a .308 Win gas gun, and I've got the most accurate projectile I could develop for a .308 Win gas gun for target practice - which comes back to hunting.  There's no downside to that hand load, no matter which way I take the shooting, target or hunting.  The only true downside is those ELD-Xs cost me more then the HPBTs - but I only have one load, that does everything for me.  That's worth the cost of the projectiles, to me. 

I hope I'm making more sense as I ramble through this topic-from-hell that I created.  I'm trying. 

[98Z5V]

5 hours ago, 98Z5V said:

I'm trying to find the reference right now, but the Nosler Accubond Long Range (ABLR) projectiles have been listed before as fragmenting down to 1700 fps. 

^^^  I fucked this up.  Those ABLRs are good down to 1300 fps, which is just crazy.  That's barely above the subsonic range, and they still do their job, that low.  Here's the info on the big ones, right from Nosler:

With ideal performance velocities between 3200 fps down to 1300 fps, the Nosler ABLR’s are able to keep weight retention up to give needed penetration to the vitals for hunters via its proprietary jacket shape while simultaneously preventing the bullet from coming apart when contacting heavy bone at high velocities at closer distances.

https://www.americanhunter.org/content/nosler-unveils-ablr-line-extension/

[98Z5V]

This is exactly what I deserve, for starting this topic, before working it all the way through in my head, in order to make the entire topic coherent in the first place, with the first post, right off the bat.  That's my fault, apologies offered.  

From my own experience, I'm still a bigger fan of the Barnes TSX and TTSX projectiles, though.  99% weight retention on those bad boys. Yes, I admit I'm a Barnes  fan-boi for that stuff.  DRT.  That's what they deliver.  In it's own tracks, drops where it was standing. 

Edited June 4, 2023 by 98Z5V

[Turd Furgeson]

This is a great thread.  Makes a lot of sense.  Still have a lot to read on what you posted.  Fascinating so far.  I''m about to load up some Barnes .338 160 GR  TTSX FB's for 8.6.  Thanks for all the excellent info!

[JBMatt]

On 6/2/2023 at 8:08 PM, 98Z5V said:

One more tidbit.  55gr 5.56, and what makes it work - fragmentation of the projectile.  THAT is what makes the 5.56 cartridge what it is.  Frag.  Upon impact. 

@98Z5V  I'm going to throw something in here about this for discussion.  You're saying "fragmentation" of the 55 gr FMJ in XM193 ball ammo, correct?  If that's correct, I'd like to challenge that just a touch.  Some years ago, Dad's best friend in Montana decided that he was going to hang up his trusty 270 Win that's he's literally taken hundreds of animals with, and set a goal of taking 20 "big game" animals with his AR.  He uses Fed XM193 and to date he has taken more than 20 "big game" animals with it.  I say "big game" because a couple of them were Turkeys, but he figures if you have to draw a tag for it, he's gonna call it "big game".  Lol.  However, I know he's taken at least 3 Bull Elk, multiple Mule Deer and Whitetails, Antelope and a couple years ago I was on a Sheep hunt with him where he got an Ewe.  The majority of those harvests were one shot kills, including the Elk. Max range on the Elk was about 150 and he said it was dead before it hit the ground. His analysis of why that little tiny bullet works so well, other than proper placement, is its speed.  It's hauling ass.  But it doesn't fragment.  It tumbles on impact and that's what causes such trauma in these animals.  It makes a nice little hole on entry, and if it makes it all the way through, a nice clean hole on exit.  The insides, however, are destroyed.

[98Z5V]

Yep, perfect, and I remember this story.  55gr, yes, that was the example.  I'm a firm proponent that you can kill anything with it, but many people (and state hunting laws) don't agree with that, just based on it's .224 caliber.  That's just stupid, on those states parts, but I get it - stupid hunters are all over, just doing what they do, out in the woods.

Now, 55gr -fragmentation is the key to that thing performing, militarily.  That's based on a 12" thick human body.  All the Doc Roberts data is out there.  For smaller critters, the 55gr is gonna kill it, explode it, basically.  For larger animals, even up to elk, it's all about shot placement, and shot placement is key.  You heart-shot a big animal, and you get the penetration - from the speed of a 55gr - well, it's not going far, if at all, if it has no more fuel pump.  It drops.  You miss a little bit, and lung it, or double lung it - that fucker is running.  It's running until it has no more oxygen, and then it drops.  That can be a couple hundred yards, and you need to track it.  With a 55gr, it's GOING all the way through, and leaving the other side, so you'll have a blood trail to track.  But, now you're tracking.  Same thing with bow-hunting.  Just a little off, and it's not heart, it's lungs, and you're now a tracker.  Spot last blood.  Spot last sign.  Now, we were just hunting.  All the sudden, we're tracking.

Spot placement is always the key to hunting.  You want it to be perfect.  If it isn't perfect, be ready to track.

Militarily, they brought back combat tracking around 18 years ago (early 2005).  I was in the first two pilot courses for that training, Level 1 and Level 2.  Badass courses that teach you how to track humans - but it's no different than tracking animals, when you're hunting.  As a kid, I fucked a few shots up - and had to find my animal.  I had to learn the hard way. 

We had an unofficial tab for that course, given at the end it it all.  I'm more proud of that than anything else I ever did in the military.

 

[98Z5V]

Just in case anybody thinks that's just some image I pulled off the internet, I have this pic for you...  

[98Z5V]

2 hours ago, JBMatt said:

@98Z5V  I'm going to throw something in here about this for discussion.  You're saying "fragmentation" of the 55 gr FMJ in XM193 ball ammo, correct?  If that's correct, I'd like to challenge that just a touch.  Some years ago, Dad's best friend in Montana decided that he was going to hang up his trusty 270 Win that's he's literally taken hundreds of animals with, and set a goal of taking 20 "big game" animals with his AR.  He uses Fed XM193 and to date he has taken more than 20 "big game" animals with it.  I say "big game" because a couple of them were Turkeys, but he figures if you have to draw a tag for it, he's gonna call it "big game".  Lol.  However, I know he's taken at least 3 Bull Elk, multiple Mule Deer and Whitetails, Antelope and a couple years ago I was on a Sheep hunt with him where he got an Ewe.  The majority of those harvests were one shot kills, including the Elk. Max range on the Elk was about 150 and he said it was dead before it hit the ground. His analysis of why that little tiny bullet works so well, other than proper placement, is its speed.  It's hauling ass.  But it doesn't fragment.  It tumbles on impact and that's what causes such trauma in these animals.  It makes a nice little hole on entry, and if it makes it all the way through, a nice clean hole on exit.  The insides, however, are destroyed.

I summary of all this, and what I'm trying to get across, he nailed it -  this guy is my point, exactly.  For hunting, shot placement is key, and he nailed it every single time with a 5.56 gun.  Every time.  The key to 55gr 5.56 working in combat is fragmentation.  Without fragmentation, you're shooting an icepick at something, and hoping that neat little hole hits THE vital organ - the heart.  Obviously, this guy was doing that, and dropped them all.  That's perfect shot placement, and you can do that all the way to the transonic barrier - with great shot placement. 

I've done a horrible job in this thread, with my intended purpose, and getting it going, logically, from the beginning - but it's getting there!  Thanks to all of you, and not to me.  Keep it going, men!

[Cunuckgaucho]

Lucky for me I like both nerd math and reading... mind you liking and understanding aren't always the same thing 

[98Z5V]

1 hour ago, Cunuckgaucho said:

Lucky for me I like both nerd math and reading... mind you liking and understanding aren't always the same thing 

The Nerd Math is the lynch pin in all this, brother - doesn't matter if it's target shooting, hunting, or combat.  The US Army zero's fixed sight 20" guns at the 25m~300m zero range - because that's Maximum Point Blank Range for a 62gr from a 1:7" twist 5.56 20" barrel.  It's just hunting information, but they don't explain that to you in the Army...   I did - I got it across to the people I had to train.  Better aim LOW on the 50m target, too - like aim at his nuts...    Everything else is hold-shoot. 

The 50y~200y Zero is great, for irons or optics (especially for hunters).  The 36y Zero is the best, IMHO, for irons or scopes-and-hunters.  Can't go wrong with the 36y Zero. No matter what caliber, with no other testing, it's gonna give you about the longest MPBR for a gun, bolt, gas, doesn't matter. 

 

[98Z5V]

The EOTech basic reticle - they do some crazy shiit now - but the common 65 MOA circle with the 1 MOA center dot.  This one:

 

If you set that center dot for a 50y~200y Zero - here's the beauty in this reticle - that bottom 6 o'clock hash is zero'd for 7 yards.  21 feet.  The perfect CQB distance.  That's just the design of that reticle, and it's on purpose.  You can have a short gun with a red dot that's on the money at 50 and 200 yards, little hold over for longer distances, and it's money inside a big room, right on the money.  Just hold that bottom hash mark.  Completely intentional from the manufacturer. 

[98Z5V]

FWIW, you can "CQB" any gun you have, even magnified optics, if they go down low enough.  3x minimum, which sucks at short distances.  4x, gonna be really hard. I have a 2~12, and on 2x, it's easy.  Illuminated reticles help greatly - don't focus through the scope, just pick up the illuminated center like it was a red dot, and run both eyes open.   If you zero 100 yards (most magnified optics), then you're 2.5" high at the muzzle - that's the scope height over bore height on most ARs / gas guns.  Most bolt guns are 1.5" height over bore.  What's 2.5" of height, at that distance, if you're clearing your house?  Doesn't mean anything for a center mass shot.  Vital zone on a deer is 7".  Vital zone on a coyote and pig/boar is 5".  Vital zone on a human is very similar to a deer.  Just make center mass shots, if it comes to that, and don't over-think it.  Run the gun.  Train with the gun, and run the gun.

[98Z5V]

I guarantee you, if you have to clear a small space or a large building across some significant distance - like Dickens had to do at that mall shooting...   Nobody is gonna be questioning you on tactics or holds, hold over or hold under, whatever...  Just know your gun...

It's all gonna come back to the Number 1 Rule in CQB...   "Yeah, but did it look cool?..."     For real. 

[sketch]

Sheesh is this a 556 thread? I have a 9mm pcc and a tavor 7 ( canned) as bed side.

That's a 308! 

I like the info bro thank you! 

[98Z5V]

1 hour ago, sketch said:

Sheesh is this a 556 thread?

That's just the info used to present the information, brother.  The issue is understanding External Ballistics.  Internal Ballistics are everything that happens inside the gun - your ammo, your parts, or your handload for example...  that all happens inside, before projectile leaves barrel. 

External Ballistics are everything that happens once the projectile leaves the barrel.

We can do 9mm PCCs, too.  Let's get a barrel length, bullet grain weight and a muzzle velocity, and get after it. 

[sketch]

No just razing Cain.