Best all-around AR cartridge to build my next rifle for

[StevieP]

I have two AR-15 stripped lowers, and suppose it's time to start amassing parts to build at least one of them into a functional gun.

Have two ARs already chambered for 5.56/.223 (.223 Wylde for both, actually), and a .308 AR.

So I'd like to do something different, but it's got to fit the standard form factor lower.

Thinking 6.5 Grendel, as it seems to be a great all-around cartridge for hunting, home defense, target shooting out to most reasonable distances, etc. (Range I go to goes out to 500 yards)

What else should I be looking at? Is 6.8 SPC II still a thing? .300 Blackout and .458 SOCOM are interesting, but seem like more of a short-range option.

thoughts on .204 Ruger, .224 Valkyrie, or any other AR-compatible cartridges?

I don't reload, so things like ammo cost and availability come into play.

The last lower may end up being a 9mm or other pistol caliber gun, but that's for another day.

 

[Deleted member 67409]

Look into 6mm ARC or 6x45.

 

[paul73]

6.5mm Ammo Breakdown: Best 6.5 Calibers for Accuracy & Distance

Thinking of a new caliber? Find out the best in the 6.5 mm family of rounds for your purpose...plus how do they compare vs the .308?

www.pewpewtactical.com

6.5CM, 6.5x47 Lapua, 6CM. Bolt action.

the easiest to buy is a 6.5CM round right now, but, all is expensive and will encourage reloading. obviously, it is a .308 world.
if you have a free lower - then may be it would make sense to have something built to handle a 7.62x39.

 

[Parker Duofold]

So you didn't say what this new build is for. You said "great all-around cartridge for hunting, home defense, target shooting out to most reasonable distances" when talking about the 6.5 Grendel. Is that your overall objective?

Home defense? With 300BLK, 458, .224 -- I don't think so.

I have rifles and SBRs in AR-9 and AR-15. I also have an AR10 and an AR in .224 Valkyrie. I'm not a hunter, competitive shooter or weekend soldier of fortune. I'm just a plinker/target shooter. I just went with the 300BLK for the next AR type option. The ammo is expensive right now but all ammo is expensive right now. I like the idea of the 458 SOCOM but that's real expensive!

 

[Deleted member 67409]

So you didn't say what this new build is for. You said "great all-around cartridge for hunting, home defense, target shooting out to most reasonable distances" when talking about the 6.5 Grendel. Is that your overall objective?

Home defense? With 300BLK, 458, .224 -- I don't think so.

I have rifles and SBRs in AR-9 and AR-15. I also have an AR10 and an AR in .224 Valkyrie. I'm not a hunter, competitive shooter or weekend soldier of fortune. I'm just a plinker/target shooter. I just went with the 300BLK for the next AR type option. The ammo is expensive right now but all ammo is expensive right now. I like the idea of the 458 SOCOM but that's real expensive!

300 Blackout for Home Defense

 

[StevieP]

So you didn't say what this new build is for. You said "great all-around cartridge for hunting, home defense, target shooting out to most reasonable distances" when talking about the 6.5 Grendel. Is that your overall objective?

Home defense? With 300BLK, 458, .224 -- I don't think so.

I have rifles and SBRs in AR-9 and AR-15. I also have an AR10 and an AR in .224 Valkyrie. I'm not a hunter, competitive shooter or weekend soldier of fortune. I'm just a plinker/target shooter. I just went with the 300BLK for the next AR type option. The ammo is expensive right now but all ammo is expensive right now. I like the idea of the 458 SOCOM but that's real expensive!

I like multitaskers. Target shooting probably #1 (isn't that true for all of us?). I'm not competitive, but I suppose it'd be nice to have something capable of competing with if I somehow ended up with a lifetime kitchen pass. I'd like to be able to take an AR deer hunting. Maybe bear. There are supposedly hogs here in NC. None near me, but they're out there. Home defense is pretty well already covered, but maybe add "insurrection" to the list.

I'm liking what I see and read about the 6mm ARC. Still leaning toward the Grendel though, for the slightly heavier bullet weights for hunting. Better availability too as the ARC is still pretty new.

 

[Deleted member 67409]

I like multitaskers. Target shooting probably #1 (isn't that true for all of us?). I'm not competitive, but I suppose it'd be nice to have something capable of competing with if I somehow ended up with a lifetime kitchen pass. I'd like to be able to take an AR deer hunting. Maybe bear. There are supposedly hogs here in NC. None near me, but they're out there. Home defense is pretty well already covered, but maybe add "insurrection" to the list.

I'm liking what I see and read about the 6mm ARC. Still leaning toward the Grendel though, for the slightly heavier bullet weights for hunting. Better availability too as the ARC is still pretty new.

Because you mention hunting, double check NC's fish and game regulations book to see if there's a minimum bore diameter or kinetic energy requirement. Many states require a bore in excess of 0.22" or 0.24", which would exclude cartridges below 6mm (6mm = 0.243").

 

[Toytowninc]

Looking at ammo availability and price last year I built an aero/faxon .350 legend. All parts same except for barrel. even magazines can be made to work if needed. Straight wall and bore diameter meet most states hunting regs. Ballistics seem decent from what I’ve seen from research so far. I don’t reload but factory options from Hornady, Winchester and federal. 300blk. May seem better but is pointless if you can’t get the ammo.

 

[StevieP]

Because you mention hunting, double check NC's fish and game regulations book to see if there's a minimum bore diameter or kinetic energy requirement. Many states require a bore in excess of 0.22" or 0.24", which would exclude cartridges below 6mm (6mm = 0.243").

That doesn't *seem* to be an issue.

Rifles​

• Fully automatic rifles are unlawful. All other rifles are legal except:
  • Rifles are prohibited by federal law in hunting migratory game birds.
  • Local laws prohibit or restrict rifles in some counties. See the “Local Laws” section.
  • It is unlawful to hunt or take wild turkeys with rifles.

 

[teamRR]

6.5 Creedmoor and Grendel are the "all around" non native calibers for large and small ARs..

300 BLK is in the same vanilla ballpark, basically an american 7.62 x 39.

Then in an actual pistol caliber 9mm is the native thing.

Then you got a long list of wierd or uncommon stuff..

All have their perks.

IMO..

if you want to carry power a little further from a small frame, 6.5 Grendel is it. A good hunting round within its capability, not a hunter, but know enough to know it would be humane for deer where 5.56 really isn't. Of course Grendel does nothing that .308 can't do better, why I don't own one.

If you want easily suppressed and a little extra in a short range game then 300 BLK. Or if you don't need all the power 9mm, which I like because unsurpressed it's not too loud and isn't going to be deadly for a long range like a rifle round.

If you want the best of the vanilla bunch for long range, or less recoil in the big frame, 6.5 Creedmoor.

 

[whatluck]

458 socom is a really cool round. I always thought 6.8spc filled it's shoes nicely too.

 

[Mountain]

So you didn't say what this new build is for. You said "great all-around cartridge for hunting, home defense, target shooting out to most reasonable distances" when talking about the 6.5 Grendel. Is that your overall objective?

Home defense? With 300BLK, 458, .224 -- I don't think so.

I have rifles and SBRs in AR-9 and AR-15. I also have an AR10 and an AR in .224 Valkyrie. I'm not a hunter, competitive shooter or weekend soldier of fortune. I'm just a plinker/target shooter. I just went with the 300BLK for the next AR type option. The ammo is expensive right now but all ammo is expensive right now. I like the idea of the 458 SOCOM but that's real expensive!

No .458 socom for self defense? Here's what a 300 grain JHP looks like after hitting a wet sand berm:

I think that would splatter a bad guy and not pass through every house on the block.

Back to OP's question- I'd recommend 300 BLK for his purposes.

 

[1903Collector]

.458 Socom is a great round, but if you go that route better learn to reload as factory stuff stars at about 2 bucks a pop and if you get into the Underwood stuff with the Lehigh bullets....Yowza!!!
I have two 458s but I reload anyway but it still cost a bit to get set up for the caliber. Outside of being cool I don't know why I have these....I'm kinda like the Joker from the Dark Knight......"I just... do". LOL

 

[Tartakovsky]

458 Socom is interesting but it gets expensive even when not in an ammo shortage so probably want to get into reloading. I say go 300 BLK. It’s great for suppressed subsonic but 125 grain has plenty of energy and velocity. It’s a great all around caliber. It reaches optimal velocity with only a 9 inch barrel, and pistol length gas systems are optimal for reliable cycling. Just don’t accidentally mix 300 BLK with a .223 upper.

 

[StevieP]

Well, I've gone & joined the 65grendel.com forum.

Glad I'm not in any hurry. Everything I potentially want to build this rifle is on backorder, if available at all.

 

[38ExtraSpecial]

350 Legend

 

[TrashcanDan]

There was somethin floating around awhile ago about the Grendel and the bolt or bolt face splitting or coming apart in an a.r.
Never looked into it, never owned it.
May have something to do with heavier or longer bullets and pressure.

6.8 spc is still a thing, theres stuff out there for it.

.224 Valk is supposed to excel at small game like yotes out past 500. Data shows it as still sonic past 1000 and around 400 lbs of energy retention. Great for steel plates out that far.

6mm ARC is supposed to walk right by the .224 Valk

.204's supposed to be fantastic for groundhogs.

I'm not saying it isn't out there, I haven't really looked for it, but 25 Creedmoor and 6 Creedmoor would be fairly slick in an a.r. platform. Maybe in a 10 chassis, not sure how long the cartridge is and I'm too lazy right now to look up the specs.

For home defense- Sorry, I got nothin. I'm a fan of fat and heavy for that stuff.

 

[StevieP]

There was somethin floating around awhile ago about the Grendel and the bolt or bolt face splitting or coming apart in an a.r.
Never looked into it, never owned it.
May have something to do with heavier or longer bullets and pressure.

6.8 spc is still a thing, theres stuff out there for it.

.224 Valk is supposed to excel at small game like yotes out past 500. Data shows it as still sonic past 1000 and around 400 lbs of energy retention. Great for steel plates out that far.

6mm ARC is supposed to walk right by the .224 Valk

.204's supposed to be fantastic for groundhogs.

I'm not saying it isn't out there, I haven't really looked for it, but 25 Creedmoor and 6 Creedmoor would be fairly slick in an a.r. platform. Maybe in a 10 chassis, not sure how long the cartridge is and I'm too lazy right now to look up the specs.

For home defense- Sorry, I got nothin. I'm a fan of fat and heavy for that stuff.

All good points. *If* I hunt with this gun, it'll be for deer, feral hogs, and bear. I already have a varmint upper.

On the 6.5 Grendel boards, they say it's a hunting cartridge that you can target shoot with. Most of those others are target rounds you can hunt with. It's a balancing act. .223 Rem will cover some of the smaller stuff, and I've got that already. My .308 AR is too big and heavy to lug into the field. Definitely want something that fits the AR-15 form factor, which rules out 6.5 Creedmoor.

 

[teamRR]

All good points. *If* I hunt with this gun, it'll be for deer, feral hogs, and bear. I already have a varmint upper.

On the 6.5 Grendel boards, they say it's a hunting cartridge that you can target shoot with. Most of those others are target rounds you can hunt with. It's a balancing act. .223 Rem will cover some of the smaller stuff, and I've got that already. My .308 AR is too big and heavy to lug into the field. Definitely want something that fits the AR-15 form factor, which rules out 6.5 Creedmoor.

You could build a light AR10 BTW.

Lots of the big frame AR's I see are 18 inch barrels, relatively heavy rails, big mag, big scope, weighs them way down.

If you want to hunt with it, a 16 inch pencil barrel, maybe even without a muzzle device or a pinned/integral 14.5, light rail like an Aero M5 Atlas in 12 inch. Keep the scope down to something reasonable, 10 round mag and it would be fairly light and handy. Pencil barrels work about the same until you heat them up, perfectly fine for hunting unless you are taking 300+ yard shots. Then you may not even need another caliber, .308 is as versatile as about anything..

 

[paul73]

If you want to hunt with it, a 16 inch pencil barrel, maybe even without a muzzle device or a pinned/integral 14.5, light rail like an Aero M5 Atlas in 12 inch. Keep the scope down to something reasonable, 10 round mag and it would be fairly light and handy. Pencil barrels work about the same until you heat them up, perfectly fine for hunting unless you are taking 300+ yard shots. Then you may not even need another caliber, .308 is as versatile as about anything..

but, why would anyone want to hunt with an AR? any bolt action, like a savage will be lighter, more reliable and simpler. and way cheaper too.

 

[Drix]

but, why would anyone want to hunt with an AR? any bolt action, like a savage will be lighter, more reliable and simpler. and way cheaper too.

Some people don't wanna be fudds all the time.

 

[teamRR]

but, why would anyone want to hunt with an AR? any bolt action, like a savage will be lighter, more reliable and simpler. and way cheaper too.

Ask OP, his use case, but if I hunted I wouldn't shy away from a semi auto that I normally shoot for fun. Nothing unreliable about an AR, I bet round count wise they would put most bolt actions to shame (who really puts 10k rounds through a bolt action, very very few, typically they see very little use).

Cost and weight, sure, hard to beat a cheap bolt action there with a semi auto.

 

[1903Collector]

All good points. *If* I hunt with this gun, it'll be for deer, feral hogs, and bear. I already have a varmint upper.

On the 6.5 Grendel boards, they say it's a hunting cartridge that you can target shoot with. Most of those others are target rounds you can hunt with. It's a balancing act. .223 Rem will cover some of the smaller stuff, and I've got that already. My .308 AR is too big and heavy to lug into the field. Definitely want something that fits the AR-15 form factor, which rules out 6.5 Creedmoor.

Yea, I been down this rabbit hole too..twice. My brother, you need to start reloading and fast!!! It's a great cartridge don't get me wrong but it's another pricey one and tough to get at times. And, I'm no hunter but I don't think I would go after a bear with a Grendel lol, but maybe you can?

Only advise I'll give ya, if you don't already know, is be aware of the type 1 and type 2 bullshit, it does make a difference when buying barrels and bolts. Again if you haven't already do some research on the Grendel cuz it's kind of a mess. There is also the 264LBC. Happy reading!

 

[paul73]

Ask OP, his use case, but if I hunted I wouldn't shy away from a semi auto that I normally shoot for fun. Nothing unreliable about an AR, I bet round count wise they would put most bolt actions to shame (who really puts 10k rounds through a bolt action, very very few, typically they see very little use).
Cost and weight, sure, hard to beat a cheap bolt action there with a semi auto.

it is not that different with saigas when they just got out. a lot of folks jumped on them, just to get their share of malfunctions, after you spend all day in the forest. i just say simpler the better.
but, to each his own.

 

[1903Collector]

You are literally a Fudd.

ZUMBOMANIA: David E. Petzal’s take on the Jim Zumbo fiasco

Almost all of your "advice" on here is absolute garbage. You are not entitled to perform a gatekeeping function. You are not the arbiter of what is or is not permissible for hunting weapons. You are not required to, nor should you, comment on every single thread.

You also have no idea about how inexpensive ARs are in states outside of Mass. Not long ago, $400 ARs were perfectly common in probably 40-45 states.

Scriv is reborn!!!!!!

 

[paul73]

Scriv is reborn!!!!!!

who cares...

 

[Mesatchornug]

it is not that different with saigas when they just got out. a lot of folks jumped on them, just to get their share of malfunctions, after you spend all day in the forest. i just say simpler the better.
but, to each his own.

Dude. We have literally 60 years of real-world testing that shows a well-kept AR-pattern rifle is perfectly reliable, even "in the forest." Will you give it a rest?

Further, OP said he wants an AR for general use, to include possible hunting. He's been a member here for a dozen years and has over 8,000 posts. It's safe to assume he understands the technology and trade-offs associated with the platform.

Nobody cares that you would prefer a bolt gun for reasons of gnomish mysticism. He said he wants an AR.

ETA: The InRange Stamp(s) of Hubris

View: https://www.youtube.com/watch?v=pC4Gqvd7T1s



View: Bolt Guns Really Are Obsolete


View: Bolt Action Obsolescence: Mike of BotR and Karl of InRange put this one to rest


View: Ian Reacts to Salty Comments About Obsolete Bolt Action Rifles


And to be clear, I have a lever gun, and my eyes on a bolt as my next purchase. I have nothing against them. But they're not magically more reliable. And frankly, a good one isn't terribly any cheaper.

 

[paul73]

Dude. We have literally 60 years of real-world testing that shows a well-kept AR-pattern rifle is perfectly reliable, even "in the forest." Will you give it a rest?

Further, OP said he wants an AR for general use, to include possible hunting. He's been a member here for a dozen years and has over 8,000 posts. It's safe to assume he understands the technology and trade-offs associated with the platform.

Nobody cares that you would prefer a bolt gun for reasons of gnomish mysticism. He said he wants an AR.

i am not excited - you all are, starting with your law student. hunt with all you want for what i care.

 

[Malodave]

I tried to build a .375 Reaper. Cutdown .308 Cartridge for the standard AR-15 Platform.
Ordered the parts from the guy. Waited 4 months without delivery of anything. He
turned out to be a Fly by Night Operation. Had to get a Charge back on my CC for
Non Delivery even though he stated no cancellations.

Malodave

 

[cathouse01]

Have you considered .450 Bushmaster? I have a 450 Bushy and it’s a great thumper. It tends to loose out to the .458 SOCOM in head to head comparisons as a pure hunting round, but as a fun range round and for home defense it’s pretty good at a much lower CPR.