the speed is reduced enough where there will not likely be any tumbling or fragmentation thereby reducing the cavity within the animal.

Is this true...?

thanks

Depends on range and  bullet type...

Our military put down one or two 2 legged charlies and tangos back in the 1960s and 1970s with some 10.5" barreled colts.  If it'll work on a 100lb person, it'll put down a 40lb coyote.

Within a couple hundred yard it would do just fine IMO.

Is there truth in the cavity part? This is a first I have every heard of this....

lower muzzle velocity = lower terminal ballistic performance and possibly no frag.  Yes, it's true, but there are variables.

77 gr FTW!

Federal Fusion is good to 300 yards out of a 10.3" barrel.

ballistic tip FTW.

Yup.

I keep 60gr Vmax in my 11.5” 5.56 carbine and 155gr Amax in my 14.5” 7.62 rifle for HD/SHTF

Humans are fragile and much more aware of injuries than animals. I'm sure any bullet will kill most any animal but only brain and heart shots actually kill quickly. Critters are amazingly hard to kill !!!!!!

I mean, in absolute terms there's no doubt that shorter barrels will lessen terminal effectiveness. Less velocity is what it is.

In the real-world, it's more nuanced. What ammo are we talking about? Distance?

I'm not sure if I'd feel great about M193 from a 10", it relies heavily on yaw and frag and needs a lot of velocity. On the other end of the spectrum, you hit soft tissue with a quality bonded soft point or heavy OTM, and the results will be absolutely devastating.

A 10.5 pistol is my truck gun I use it to shoot critters with all the time. I can tell you a 60 grain v-max or 75 grain otm will destroy just about everything that has fur on it in north Alabama. Not to turn this into a hunting thread but if you use a heavier soft point it does a nice job on hogs too. Admittedly I have not shot anything past 250 yards. That’s about the longest shot I can get in most of our hayfields.

We have killed a few (7 or 8) coyotes this year with 11.5" 5.56 using vmax bullets. We did lose 2 more but both were 200+ yards and questionable hits. That said, we are building 12" 6.5 grendels for our SBRs for just a bit more power on those longer shots.

ETA: My calculations say that the 11.5 barrel costs us about 50 yards of effective performance over a 16" barrel.

I'm not sure if anyone will find this relevant, but I had this conversation (for about the fifth time) on Friday with one my employees ....

He is an EXTREMELY avid coyote hunter.  He competes in tournaments as often as possible.  He has a $4,500 thermal on one coyote rifle, and a $1750 NV on another.  He has hand held thermal and NV equipment, has call blaster equipment, digi video recording equipment, etc.  Two weeks ago he and his hunting party called in and shot FOUR in a single field.  I watched the thermal vid of this.

Anyway, that is to lay the ground work that he's not some 20 year old with a Savage Axis sitting in his truck bed drinking Busch Light and hoping for a shot.  He's extremely serious about coyote hunting (and goose hunting ... just came back from two weeks in Canada).

He started with a 20" 5.56 AR, but found a "great deal" on a really neat 18" 6.5 on a predator hunting forum (Predator Masters ??? something like this).  I looked at the specs and told him it should be a good enough for his use.  He bought it, and stuck the $1750 NV optic on it.

The 6.5 will not put a coyote down cleanly.  I've watched enough of his thermal videos where he clearly hit one just to have it run off.  They've recovered a few this way, and found the lack of fragmentation has been detrimental to quick stops.

He ended up building a 16" 5.56 (really nice rifle with a cerakoted camo Aero matched upper / lower set).  He's back to DRT shooting coyotes with 45gr.

Purpose of bringing this up ...

Fragmentation leads to massive trauma / blood loss which leads to quick death.

Small pin holes that don't destroy the central nervous system or heart may lead to death (slow blood loss) but it won't be a DRT situation.

ETA: the relevance being ... shorter barrels reduce velocity which in turn reduces the likelihood of projectile fragmentation.  Therefore, a 10.5" or 11.5" 5.56 barrel will probably be less effective at producing "DRT" (dead right there) kills on coyotes.  The coyote would probably die from its wound (entry / exit) but the probability of recovering the carcass is lower (since it might run off to die from blood loss after the adrenaline wears off).  Anyone that has been deer hunting will understand what I'm talking about.  Therefore, I guess the shooter has to determine their purpose for hunting coyotes.  If they want or need to recover the body (sell the pelt or turn in for competition purposes) would say "no" to a short barrel but if you're just trying to keep predators off your property then "yes" to a short barrel.  We had a big coyote problem at our hobby farm.  My wife and I shot them with everything from a 20ga shotgun to a FN Scar-17.  We didn't care about the bodies ... and actually preferred for them to run off and die in the woods so we didn't have to deal with their stinky / flea ridden / nasty carcasses.

So far I have dropped 1 coyote at 80yds, 2 hogs at 190yds with my 10.5" .556, all one shot, drt kills

Head, lung, heart or neck / spine hits?

Size of hogs?

ETA: 80 yards is a close in coyote.

300 blackout :)

coyote, lung shot

first hog, 175pounds spine shot,

second hog 60 pounds head shot...

Most coyotes are less than 100yds, called out of the brush, not scared of humans or trucks.

On hogs, most on wheat fields, so from 20 yds to as far as you can see in places. I will not shoot at over 200yds personally.

If you are shooting coyotes, use something like a 50gr VMax.  It will fragment at all applicable distances.

All the hubbub about barrel length and fragmentation was centered around military use of M193 ball.

If you are concerned about ballistic performance on larger animals.  70gr Barnes TSX will expand out of an 11.5 on a deer at applicable hunting distances for an AR pistol on deer size game.  Don't be a fool and start lobbing them in from 500 yards.

Solid post. Honestly... If I had to do it all over again with my AR's... I'd have [1] 14.5" barreled AR, and the rest would be, 11.5, and 10.5's exclusively. There are so many loads available that make an AR pistol or SBR more than effective. We aren't limited to 55gr and 62gr ammo and haven't been for a long time. I shot a wild dog that was absolutely Huge and that had been stalking my giant German Shepherd and Chow-Chow nightly to the point I was afraid to let them out in the fenced back yard without going out armed with them. This wild dog wasn't afraid of my big ass at all either and suddenly lots of posted signs of lost fluffy, have you seen my pet, etc, starting happening. It pained me to shoot a dog and I had lots of trepidation. But after it attacked another neighbors dog and killed it any reluctance after that was totally dissipated. So just after dark one night I shined a 500 lumen Streamlight dead on him and popped his ass; with a 40 grain varmint tipped Winchester .223 round at 85 yards off my back porch. The blood mist/splatter was the most violent I've ever seen. This wild dog dwarfed my GSD. But one center mass hit with my 10.5 and it was lights out, one round to the neck where it met it's torso. I use 75 and 77 grain ammo when I want to reach out and have zero reservations of what SMK's and OTM's do at 200yards and under.

I use this to help me figure out ammo types for my rifles:
http://www.bergerbullets.com/twist-rate-calculator/

As many have already noted, bullet selection in that 10.5" AR15 could be critical.  Extreme distance can play a huge part too.  And as to coyotes taken by any bullet, I kind of find them to be quite fragile compared to critters like pigs and even some deer.

The earlier post about the "6.5" has me scratching my head.  I'm assuming that was a 6.5"G".  That had to be a bad bullet selection or some other variable.  While I think even most short barrel 5.56 guns are more than capable of taking pigs and coyotes with the right bullet, a 6.5G is every bit the equal or better of a 5.56 in equal barrel lengths.

I'm certainly not poo-pooing the 5.56.  My last pig and coyote were shot DRT with home loaded 68g and 75g bullets.  And they were match, not good hunting bullets.  I will say, however, that I've been moving more to my 300BO with a 110g V-Max moving at close to 2400 fps in a 16" barrel.

Arguments on FB...or here...tons of variables with a lack of specific information and there you have it.  So many good bullets to choose from...getting a bullet on target...shooting within a reasonable distance envelope for caliber...there is no one-size-fits-all.

its all about the dick waving.

this is like watching CNN. once a week this comes up. I love my 7.5 and know itll do what needs to be done

AR 500 plate Yesterday, 180 yards Military 62 grain, dimpled plate from a 11.5'" Daniels Defense Barrel Build. Vortex Razor AGM UH-1 sight. 12" plate.

dimpling a plate with steel core is different from potential terminal effectiveness on soft / living targets

If 6.5 G out of an 18inch barrel isn't killing coyotes someone needs to re-evaluate his bullet selection or his shooting skills. I don't have a 6.5 but I do have a 6.8 that hammers coyotes, the two calibers are close enough that there's simply not a reason that they wouldn't work in a similar fashion.

Buddy of mine is a serious coyote hunter, 200+ last year. Does lots of calling and takes 400yd + shots often, cleans up on pair and triples while solo hunting. Uses 22-250 suppressed with 80grn Bergers. Exit wounds and blood splatter at shorter ranges are horror movie quality. Had one with a coke can size exit wound a few days back, still ran 60yds. As above, shot placement and ballistic performance matter. If I was planning on hunting with a 10.5”, I’d have 45-50grn varmint style ammo loaded, it’ll still ruin any bipedal’s day.
Check the blood splatter on the corn stalk
Attached File

I wouldn't depend on a FMJ to tumble or fragment on something that might only weigh 30 lbs at normal speeds.  Truthfully, there is better ammo for shooting game than FMJ, unless you just want a small hole in and out.

That lil bastard has a nice pelt. Time to break out the skinning knives and get to work.

Get off of Facebook that’s my advice