Ar15 in 556 or 7.62 x 39

[loadedp3at]

Pros and cons of each one. Looking at one for hunting and defense.

[Snaveba]

I know this was not on the list, but

300BO.

Pros

Same BCG as 5.56 so you could just swap barrels if you want 5.56  

Same  mags as 5.56

good subsonic round if you go the suppressor route 

As decent a hunting round as 5.56 or 7.62x39

 

Edited September 10, 2022 by Snaveba

[DL126]

For me, hunting is typically inside of 100 yards.
I really like an AR in a pistol config for work of those distances.
Very handy and easy to maneuver in the woods/brush.
Even inside a 4'x4' box blind you can easily swing from window to window while on the gun.

With my 10.5" 7.62x39 ...
I have 154 gr Tula soft nose and some soft nose Federal that is used for hunting.
I don't have any numbers for this ammo outta the setup yet.
But what I do have is data for 122 gr FMJ ...
MV of 2162 FPS
At 100 yards this puts 997 ft-lbf of energy on target.
At 200 it retains 776 ft-lbf.

Compare that to an 18" .223 using 55 gr Hornady Spire Point.
2940 FPS MV
At 100 yards this is 800 ft-lbf of kinetic energy on target
At 200 it drops to 599 ft-lbf

I also have a 10.3" .223 that I hunt with but I have no data for that one.

I have taken deer with all of these setups.
All with one shot ... and all at 100 yards or less. (The pistol shots were inside 50 yards)
The pistols are configured with reflex style red dot sights.
Scope on the 18'er.

For some reason that I can't explain, for general work inside 200 yards, I gravitate toward the 7.62 every time.
I really like that setup.
The only con that comes to mind for the 7.62 might be ammo availability at some point in the future.
Right now, the aforementioned Federal rounds are non existent as far as I've been able to find.
And with future bans on imported Russian ammo ... might wanna get what you can quickly.
Possibly worth mentioning also, I make sure to keep an xtra bolt and correct firing pin on hand for the 7.62.

My lovely wife has gone nuts about hunting.
She also went nuts over that 7.62 pistol.
So now we have 2. 

My $.02

[scatman]

Depending on application, for everyday versatility, 5.56, or as someone stated above,  and the much better option, .300BO. 7.62x39 is a cool option for a range toy, has good take down power, but the accuracy isn't truly there. Or, just go big boy .458 socom, those are the real fun.

[Smith]

7.62x39 is essentially a 30-30. Taken more game in north America than any other round. The .300 BO only advantage is subsonic. 5.56 is great on small deer and down, but looses on the bigger game. Open range caliber? Not the greatest. Anything under 200 yrds and any brush/cover? x39 

As to the 7.62x39 accuracy,  Handload a x39 the same as the .300 BO and the ballistics are clear. . The accuracy nonsense is comparing steel cased mil surplus out of an AK/SKS to handloaded match AR 300BO platforms. Also, shoot it out of a .310-.311 barrel instead of a .308. Better range, power, stability, consistency, and reliability. Much of it has to do with the neck of the x39 and the case to handle the appropriate  charge that the 300BO /5.56 case can not handle. 

Pretty good overview https://thebiggamehuntingblog.com/300-blackout-vs-7-62x39/

[DL126]

The article Smith linked above mentions the 6.5 Grendel which is loaded in a 7.62x39 case ....

If I'm gonna hunt open areas, or if I'm shooting targets at 300+ ...
I'll be behind a Grendel.
I can post that data for you if you're interested.
That is a very slippery and effective round out of a small frame AR.

Edited September 11, 2022 by DL126

[Snaveba]

1 hour ago, DL126 said:

The article Smith linked above mentions the 6.5 Grendel which is loaded in a 7.62x39 case ....

If I'm gonna hunt open areas, or if I'm shooting targets at 300+ ...
I'll be behind a Grendel.
I can post that data for you if you're interested.
That is a very slippery and effective round out of a small frame AR.

I have one of those as well.

[KahrMan]

3 hours ago, DL126 said:

The article Smith linked above mentions the 6.5 Grendel which is loaded in a 7.62x39 case ....

If I'm gonna hunt open areas, or if I'm shooting targets at 300+ ...
I'll be behind a Grendel.
I can post that data for you if you're interested.
That is a very slippery and effective round out of a small frame AR.

Did you say a small frame ar in 6.5 Grendel…

[Snaveba]

Not small frame but…

[DL126]

When calling it a "small frame" ...
I'm referring to the fact that it's an AR15 frame, in lieu of an AR10 size. 

Edited September 12, 2022 by DL126

[Snaveba]

I realize that. Mine was just not a pistol like KahrMan’s.

[TSG]

Been thinking about this a bit.

Ballistically, any of the mentioned calibers will do the job with the right bullets. 6.5 Grendel definitely has an edge the farther out you go and the 300bo has an edge suppressed with subsonics. Between 7.62 and 5.56 specifically I lean toward 7.62. Bigger frontal diameter and more energy.

The problem I think is in availability of decent bullets. Haven't seen anything but soon to dry up Russian steel case FMJ in quite a while. Nothing with soft points or even heavier bullets. 6.5 Grendel is very expensive per shot. 300 is almost as expensive, but availability seems to be improving on different factory loads.

None of the three compare to the availability or price of heavier hunting type bullets for 223/5.56.

So if price and availability don't matter to you, 7.62 and 6.5 Grendel are probably your best bets. If you want to shoot suppressed a lot, 300BO. But if price and availability are a concern, 223/5.56 is the clear winner. Just try to get something with a 1:7 twist so you can really take advantage of the heavier bullet options.

[THA KERNALLL]

I would say 7.62x39 for hunting and 5.56 for home defense. With all the bans on russian ammo, that still wont dry up the supply. Multiple countries make ammo, plus american companies make ammo now. You should get both

[farmerpabs]

556!

[RatCat454]

If the choice is between the 5.56/.223 or the 7.62X39, I agree with "Smith".  

It is interesting that some reloaders of 7.62X29 are swapping out the steel core military bullet in cheap surplus rounds for soft points to achieve economical hunting ammunition.

[Chemgeo]

I don't know about for hunting, but for defense, none of the 7.62x39 ARs on the market are consistently what I would consider 'duty grade' reliable, and it mostly comes down to the magazines and receiver geometry just very often being a problem. If you want 7.62x39 I would recommend getting an AK, a mini 30, basically anything built for the round. 300 BO is probably just a straight better option for an AR platform in a similar round.

That said, 5.56 is fine for hunting deer with modern ammo inside 100.

[221 Fireball]

I've killed deer with both the .300 BO and the 7.62x39. In my experience, the 7.62x39 has more energy than the Blackout on knocking 'em down. I use Hornady SST in both rounds. Best performing bullet I've found for thin skinned game when using the smaller calibers. Both mine are in bolt guns. 

[Alleycat72]

⁹The biggest problem with 5.56 is the bs about the ammunition. The 7.62x39 has more diameter so in fmj form, it will preform better than the 5.56. If you run modern expanding ammunition, the 5.56 is better. As far as 7.62x39 vs 300 blackout goes.......a 125 gr .308 bullet going 2350  vs a 123 gr.311 bullet goes 2350 is the same thing in my book. The 308 bullets are much better as far as technology is concerned.  Stop thinking military. The 5.56 is fantastic if you can shoot. E=(W*V2)/(14000*gc).

I can't tell you how many things I've killed with a 5.56, but it's staggering. I've killed things from 10lbs up to 300 lbs and every thing in between. Good ammunition is everything.