Sent this to a friend interested in building an AR15 for night vision hog hunting.
Since that is the PURPOSE for this rifle. MOST shooting scenarios will be between 70-120 yards.
I like to keep bullets above 2000FPS for proper expansion. (Yes, there are many bullets that expand below that range.)
I also like to keep impact velocity at a minimal of 1000 foot pound. (Yes, you can drop hogs below that. Many use an 800 ft.lb. as measurement).

Using ISnipe App. (and its limited bullet choices) I picked what I believe two common bullet weights.
It’s been my experience that boxed ammo printed information is not correct in velocity. Usually a faster speed then actual chrono. info.
I then marked the maxed distance I would feel comfortable shooting that bullet.
Figured this might be helpful for you folks since there are so many different calibers to choose from when it comes to building an AR15 Hog Gun.

The choices of AR15 caliber are numerous. I did not cover many market calibers such as 7.62x39, .50 Beowulf, .458 Socom and others. The list developed below are the calibers my friend is considering.

.223/5.56
55gr Barnes TSX @ 100 Yards Max
62gr Barnes TSX @ 50 Yards Max


6.5 Grendel
90gr Speer TNT @ 215 Yards Max
129gr Hornady SST @285 Yards Max


6.8 SPC
85gr Barnes TSX @ 210 Yards Max
110gr Barnest TSX @ 250 Yards Max


.300 BlkOut
123gr Remington MC @ 130 Yards Max
147gr CMMG FJMBT Unacceptable
There are a lot more bullet options not listed on ISnipe. Look below hand load data for more information


Below is hand loaded bullet, velocities and ft.lb.
.223
69gr SMK @ 63 Yards Max
77gr SMK @ 100 Yards Max


.277 Wolverine (NOT 6.8 SPC but a 6.8x39)
85gr Barnes TSX @140 Yards Max
90gr Gold Dot @ 175 Yards Max


.300 BlkOut
110gr Hornady SP @ 160 Yards Max
130gr Barnes TSX @ 55 Yards Max


Boxed Ammo Comparison
.223/5.56
55gr Barnes TSX @ 100 Yards Max (5th)
62gr Barnes TSX @ 50 Yards Max (6th)

6.5 Grendel
90gr Speer TNT @ 215 Yards Max (3rd tie)
129gr Hornady SST @ 285 Yards Max (1st)

6.8 SPC
85gr Barnes TSX @ 210 Yards Max (3rd tie)
110gr Barnest TSX @ 250 Yards Max (2nd)

.300 BlkOut
123gr Remington MC @ 130 Yards Max (4th)
147gr CMMG FJMBT Unacceptable

Handholds
.223
69gr SMK @ 63 Yards Max (5th)
77gr SMK @ 100 Yards Max (4th)

.277 Wolverine (NOT 6.8 SPC but a 6.8x39)
85gr Barnes TSX @140 Yards Max (3rd)
90gr Gold Dot @ 175 Yards Max (1st)

.300 BlkOut
110gr Hornady SP @ 160 Yards Max (2nd)
130gr Barnes TSX @ 55 Yards Max (6th)

Again this is not an extensive list. But a beginning point.
Hope this is helpful.

Very good comparison.

So ultimately which Grendel load is he choosing?
Seriously, based on this where r y'all leaning towards?

It's simple physics that the 6.5 Grendel and the 6.8 SPC will have the most energy (of the one's you calculated), since they have the most powder capacity. But if you throw cost of each round into the equation, they begin to lose their flare. For the money, it's hard to beat a 300 blk out. I have been hunting with it for about 3-4 years now. I've killed a lot of critters with many different calibers. For low cost, plenty of energy, good penetration, and great bullet expansion, the 300 blk out has worked flawlessly for me. Push a 125 grain bullet about 2200-2300 fps, and it will perform very well on any Texas animals. I run it in an AR and in a Rem 700 bolt gun, and it does well. The bolt gun also pushes the bullet about 100-120 fps faster than the AR, so I'm running close to 2400 fps in a 16" suppressed bolt gun.

I was mainly trying to steer him away from lighter caliber.
Yes, the lightest caliber in the group has definitely killed its population of hogs at night.

I too have hunted with the 300 BLK since 2010. Def. downed plenty of hogs.
Most 300 BLK folks I know custom load some really sweet bullets and loads.

But as the AR15 market progressed the 6.8 and 6.5 definitely have an edge in the market.

Great info guys thanks!!

Great info. Were barrel lengths taken into account to generate published velocities? I ask as I've heard the Grendel needs a bit more barrel length than the 6.8 or 300 BO to get to its optimum velocity.

Nope... unfortunately its not an option you can input on ISnipe. Two of my other ballistic apps have it as an option. The layout data would have been cumbersome to share. Optimal barrel length, according to Bill Wilson, is 20" but my buddy runs an 18" and if the bullet hits the hog. The hog had gone down. I have another friend who built one around a 24" Hbar for precision shooting. It's NOT the Creedmore but nor would I hunk that thing around for NV hunting because of its weight.

I believe the 6.8 achieves complete powder burn at 15-16"
The 300 achieves powder burn, I believe, around 9-10"
Longer barrels will produce more velocity to a point.
So if you want to go SBR then the Grendel may not be optimal route.

He's pricing items out including a thermal scope with the package.
I will let you know when he makes a decision.
HIs hunting scenario is very similar to mine for day/night hog hunts. Most shots being between 70-120 yards.
With that as the standard he's got a lot of options.
As with most things hunting. It's gonna come down to his (wifes) max budget.

Lot of mis information about the Grendel out there and even some that is old on Alexander Arms website that should be updated but Bill is off to other projects.

If I were doing a SBR barrel length would come into play for sure.

Under 12.5 inches I would go with the 300BO
12.5 or over the 6.5 Grendel, know people that use that length and target shoot to 500 yards with it and hunt to 200+ for deer.

Hornady data on their website for the Grendel with a 16 inch barrel was actually shot with a 14.5 inch barrel with a pinned flash hider.

I know you didn't want to compare the 7.62x39, but it has everything you are looking and it is dirt cheap to shoot.

$6 per 20 for steel case and is accurate in the AR setup is hard to beat.