6.5 Grendel, 6.8 SPC, 30 AR or 300 ACC BO.

[pennlineman]

OK, I'm bored. I'm thinking of doing 3 more AR builds to finish of my collection.

The first one is real simple, a 16" 5.56 carbine since I'll generate an extra upper when my SBR tax stamps gets approved.

The second perhaps a little more complex. I'd like a really accurate Intermediate to long range rifle with a 20-24" BBL. Here I'm thinking 6.5 Grendel, 6.8 SPC or possibly the .30 AR. The 6.5 and 6.8 seem to be the most common. The .30 seems destined for failure but I don't care, I'll get enough brass to reload for it and factory ammo is still available. Remington still makes one in this caliber. Remember the purpose of this rifle is target.

The third would be a hunting rifle. This rifle would probably be a carbine with a 16-18" BBL., a little more handy for hunting. Perhaps Pa with pull its head out and allow semiautomatic hunting before I die of old age. Never the less nothing prevents me from hunting with it in another state.

What I have already is an AR pistol with a 10.5" 300 blackout BBL that I could easily put the upper on my SBR when it's approved. I like the 300 BO because it really is as simple as swapping uppers and I don't need special magazines or BCG. Also, it achieves good velocity in very short barrels. The thing I'm dubious on is the power. Some will say it's like a 30-30. I tend to disagree. While it may achieve muzzle velocities similar to the .30-30 it does it with 125 grain bullets vs 150. Regardless, it is, in my mind a 150 yard hunting cartridge. Which leads me to these which you can reach out a bit with....


I really like the Idea of the 30 AR, it has a significant jump in velocity of the 300 BO. Being completely honest I'm a 30 cal fanboy. This appeals to me the most mostly for that reason alone.

Then we have the 6.5 and 6.8.

So.....

I guess what I'm asking is if you were to build the 2nd and 3rd rifles which caliber would you choose and why. It's OK to disagree, if I didn't want your opinion I wouldn't have asked.

[Yellowfin]

For longer reach the 6.5 is definitely the way to go unless you go with a 6x6.8 type (.240 Tomahawk, 6mm WOA, 6PDK, etc.) or 6mm Grendel derivative (243 LBC, 6mm AR Turbo, etc.) which drives a high BC bullet much faster than the Grendel so it's a little better overall. That increase in performance would translate into good results for hunting, just use the appropriate design of bullets there--basically whatever type you see loaded in the 243 Winchester. Not that the Grendel or regular 6.8 are bad choices either, and the 6.5G will do both hunting and paper well (and of course the 6.8 has its reputation as a quite capable game zapper but not paper puncher), but it seems the necked down variant makes improvements in utilizing the action length limitations of the standard AR.

30 caliber AR rounds run especially afoul of the action length limitation: long bullets that fly better (drop less, lose less velocity) eat up powder capacity, and short stubby bullets lose effectiveness too fast. The reality is that a cartridge that can fit in the AR magazine and bolt face really works best with a 100-120 grain bullet because the max length times max diameter is going to give you a defined max volume which can only drive a bullet so fast and it needs a good amount of speed to work. So a 100-120 grain bullet in 30 caliber just plain sucks for BC so the useful range is going to be lousy if you're used to full power stuff. Narrowing it down to .277 (6.8mm) helps a good bit, .264 (6.5mm) better still, and by the time you get down to .243 diameter (6mm) it's quite nice and behaves like what you'd want from a rifle.

[wanneroo]

With 300 BO a lot of it is bullet selection. I did some testing with 130g SOST military bullets from Federal. They are a lead/copper solid hybrid and they do some explosive damage when testing them on some left over thick wood posts left over from range building construction.

300 BO to me is ideal for anything less than 200 yards. Logistically as far as caliber conversions go it's simple and doesn't require any special magazines.

[arjohnson]

For target intermediate to long range the 6.5 would be my choice in either Grendel or Creedmoor, personally I'd go CR.

[pennlineman]

With 300 BO a lot of it is bullet selection. I did some testing with 130g SOST military bullets from Federal. They are a lead/copper solid hybrid and they do some explosive damage when testing them on some left over thick wood posts left over from range building construction.

300 BO to me is ideal for anything less than 200 yards. Logistically as far as caliber conversions go it's simple and doesn't require any special magazines.

Thanks Guys!

I like the 300 BO for what it is and agree it would work well within its limitations but still considerate as an underpowered .30-30. Given that most of the deer I've killed in Pa were less than 100 yards and with proper bullet selection I'd much prefer it over the 5.56. Given of course the Commonwealth ever decides to step out of the 19th century. I'd like to have something that reaches the 300 yard line with authority, my self imposed range limit for hunting. I've been googling a lot since I've started this thread. I got to tell you guys I'm liking the .30 Rem AR. Published load date puts it at 2600-2650 with 150 grain bullets. Think .300 Savage out of an AR and nipping at lower end .308 Win out of a standard sized AR is really appealing. I understand the BC is better in the smaller calibers so.....

I'm really leaning towards the 6.5 Grendel for the target rifle for that reason. I'm not seeing anything the 6.8 has over it.

I don't mind messing around with obscure hard to get cartridges, But for now I'm going to stay away from the wildcats although this may become more appealing depending how much I get into this. The 6mm's do look interesting. Perhaps someone will get one on the market before too long.

Keep the opinions coming. This is a new area for me and all is appreciated!

[Berks_Iraq_Vet]

I built a 6.8mm AR. Great, flat shooter.

[R L Suehr]

Oh come on now, for you pennlinemen there is only one choice for a hunting ar. 458 socom.

I'd be disappointed in ya if it didn't start with at least a 4 .

[pennlineman]

Oh come on now, for you pennlinemen there is only one choice for a hunting ar. 458 socom.

I'd be disappointed in ya if it didn't start with at least a 4 .

Hmmm....

I do have a .45/70, .458 Win mag and .458 Lott. Always more room for another thumper, perhaps at a later time. Right now I'm contemplating on a future hog hunt and would like to have something that'll reach out a bit with more smoke than a 5.56 without going to a full sized AR-10. Really just want to hunt with an AR. I'm enjoying longer range shooting too, hence the target rifle.

[R L Suehr]

Hmmm....

I do have a .45/70, .458 Win mag and .458 Lott. Always more room for another thumper, perhaps at a later time. Right now I'm contemplating on a future hog hunt and would like to have something that'll reach out a bit with more smoke than a 5.56 without going to a full sized AR-10. Really just want to hunt with an AR. I'm enjoying longer range shooting too, hence the target rifle.

Funny, I've been considering doing a socom in order to go hog hunting down south with a cousin of mine next year. Ballistics wise it's pretty close to the 45/70 (which is another choice I'm considering in a lever gun) and they can share bullets for reloading purposes. I don't envision anything past 75-100yds for a shot on a hog hunt, but then I've never been on one so who knows.

If PA ever allows it for deer season, I'd go 6.8spc myself. I like the looks of that one for most of where I hunt.

Just to muddy the waters a little more check this out: http://onlylongrange.com/bn36-carbine-assassin/

If only money were no object, I'd already own one of those.

[dkf]

Hmmm....

I do have a .45/70, .458 Win mag and .458 Lott. Always more room for another thumper, perhaps at a later time. Right now I'm contemplating on a future hog hunt and would like to have something that'll reach out a bit with more smoke than a 5.56 without going to a full sized AR-10. Really just want to hunt with an AR. I'm enjoying longer range shooting too, hence the target rifle.

The .458socom is good out to around 150yards, though guys have shot game to 200yards. If you use an expanding bullet you just have to make sure it expands at the velocity at said yardage you shoot the game. Another option is the .375socom which stretches the range more. I went with the .458socom too hoping PA would go semi auto for hunting soon. There was an old dude that owns a big ranch and shoots his socom out to over 1000 yards at cars that trespass on his property. Hell of a holdover.

For long range the 6.5 is the best you mentioned and it does like longer barrels. For hunting the 6.5 and 6.8 are both better than the .300blk. Frankly the .300 does nothing great, just a lot of things ok. There are also a LOT of wildcats out there. The .25-.223 is a decent deer cartridge if you have a lot of .223 brass laying around.