Home Forums Hunting & Shooting AR and Tactical Rifles Somewhere between 223 & 308

I have a 223 & a 308. Looking for something I between and have a AR-15 lower. Recommendations?

6.8SPC

6.5 Grendel

My recommendation is to throw anything that isn't .223 in the fugking trash can.



Dave

.260 or .243

Hmmm, maybe where to go?

I'm planning on Tulsa in April. That show may be the place. The caliber may be limited with an AR-15 lower?
I'm thinking an 18" or longer barrel. One of mine now is BPMS and it seems to work well.

Basically I need an entire education. I'll probably need to read a lot more of these posts. The magazine articles all seem to say buy what I'm writing about.

I intensely hated the issue M16 and have ignored AR's for a long time.

Second the 6.8 SPC

6.8 SPC

6mm / .223

Hard to suggest without having a CLUE WHY you want something between, IE uses.

6.8 SPC for hunting, 6.5 Grendel for targets.

have them all,6.8 wins hands down for a deer/hog rig and will fit your lower fine, ammo is easy enough to get these days. a 16" barreled six 8 is my preferred carry gun. the .223s just sit in my safe any more. the POF .308 gathers dust and I finally took the barrel off the Grendel and put a 6.8 on it.

as you can see I'm a believer..

Get a bolt...

Anything beyond a 223 in a AR tends to be heavy and you won't keep it long term.

And get a 260 if you shoot big game.

If you only shoot yotes and such go 243.

Not meaning to hijack, but maybe this will help target the answer.

How do the ballistics of the 6.5 Grendel and 6.8 Special Purpose Cartridge compare? Quick benefits of each.

Just looking for the skinny between the 2 cartridges.

Thanks

.300 Blackout

You could always rock a Nemo 300 WinMag for your 'big' AR, and let the 308 be your midsize.


https://nemoarms.com/rifles/

Fail to see how all the large suggestions fit on his AR15 lower...

FWIW I'm back to the point if I can't do it with a 223 and good bullet, then I'm going to a bolt gun also....

I've had an AR10 lower for 15 or so years... never found any reason to build it...

I have a .308 and I like it but I can't see myself picking it up over a bolt gun. I have it for a novelty more than anything although it's still very accurate and reliable. .223 is king in the AR platform, everything else is just "fun".

6.8 you'll never thank me latter

I was just being a smartazz.


223/5.56 for the win on the AR15 frame.


If you just have to go up, on that frame, the 6.8 seems like the logical choice.

Couple of thoughts:

.300 Blackout - buy a barrel only, use your existing 5.56 components and shoot.

Probably cheapest for your build investment. Several opinions on the value unsuppressed, and whether you are shooting sub-sonic or above.

6.8 SPC - buy barrel, bolt, and magazine, and use existing components.

My alternative caliber favorite - but doesn't mean it's the "best" for you, or your plan. Good bullet choices, plenty of information on the round, and finding components has been easy of late.

6.5 Grendel - buy barrel, bolt, and magazine, and use existing components.

No experience shooting it, but price out the components and ammo before jumping.

In the .308 level cartridges, weight of the rifle, bulk of the rifle to carry it, and the lack of standardizing in the build components are the three issues most builders gripe about IMHO, YMMV.

I have built a couple, they run Ok for what I need. As stated, I don't see replacing bolt guns with them, but I could see a pig hunt and a high stand...or a DJ-Jones type hunt being a doctrinal truckload of fun.

6.8 spc2 done next question. Lol

Ya know I heard about this 6.8 thing. From the video below it seems to work pretty good.
Thermal hog hunt- video

I had a 300BO,yea it works. The 6.8 SPC is more suited to hunting in my opinion.

the lr10 aint the most accurate rifle and it's dam heavy, but for my 'type hunt', it's hard to beat. still, sometimes hogs soak up a lot of 308 damage. took three hits to bring down the first one. as you can see, several others left a few parts on the battle field and still made it to cover.

a friend was by my side shooting a 223. he WAS able to make one squeal!!

It all depends on what you need/..... I've killed a LOT with the 300/221 out to 200. I"ve never shot anything other than suppressed subs

If I was in D Jones shoes I can see the use of the 10....and might be leaning to 338 federal myself....

Nothing funnier than a 30-30 and a .270 that have had the last bit of decentness sucked out of them.

But hey, pigs are tough. TFF.



Dave

I'm impressed with the 6.8 after only a month with one. This rig weighs 7.5 as it sits, only cost $911(including scope and mounts), and shoots moa frequently. I just built it the first part of January, so only got in two late season doe with it. After busting shoulders on both and still getting exits with the 120SST at 2590 MV, I feel fairly confident it's going to be a winner for medium game. With a .400 BC, it's not too bad and offers more than the 5.56 in my eyes. It's so much easier to tote vs an AR10.

You can get 90 grain bonded Gold Dots for only $9.99/box, so ammo isn't too bad. Many claim the GD loads shoot quite well and perform great on pigs.

Tough to trump 120gr's @ 2,590fps.


Sign me up!



Dave

I have owned/played with the 6.8 SPCs and 6.5 Grendel.

Went right back to .223s and .308s.

I would suggest that you just load up some 77 grain SMKs or buy MK262 and shoot it at longer distances.

You will be money ahead .

i certainly can't argue with the voice of experience, but not all my hogs run off after being shot. sometimes a 168gr amax traveling at... well... i don't know what it's traveling at, but it knocked this guy off his feet AND sent fireworks out the other side!!

Mac i cannot deny the 5.56 kills deer well as I have used it, on the other hand I am enjoying the 6.8SPC as well.

WOW!!!





Travis

Rost,

"FWIW I'm back to the point if I can't do it with a 223 and good bullet, then I'm going to a bolt gun also…."

Are Your 300 Blackout(s) bolt guns only? If so why no AR in the Blackout?

Reason I ask is I've got a box of AR parts and am going to do another build… was thinking down the lines of a 6.8 SPC or a 300 Blackout (I/The kids have 2 bolt guns and a single shot in the 300 B.O.).

Thanks,

Jerry

No need to bridge the gap, unless you want to hunt with an AR in a state that has caliber restrictions. The 5.56 does most things and if you want more, you probably want a .308. After years of saying I wouldn't I just got an M1A scout/squad and am liking it so far. I like the Garand action and traditional stock or I would have just stayed with an AR. I probably don't *need* a .308 battle rifle, but it is fun for me and that's what counts. FWIW, .308 AR's didn't really do anything for me, but everyone is different.

OK I had a thought last night but am not sure if I am missing something but here goes

I know NOTHING about 6.8 but from the posts it looks like a fine round. When I think of the gap I think of the 7.62x 39

and as I look in my Hornady book the 7.62 and 6.8 have similar bullet weight choices and not exact but similar velocitys.

My Favorite ARs are 7.62 x 39 normally you will always find one in my trunk.
I dont know practical hunting distances with the 6.8 and I believe the x39 is probably a less than 150 yds (probably OK for hogs)

I checked to see if there was any openings at the Fire Hog Hunt (there was not) but my first thoughts were I have a box of TSX bullets for x39 and I would take an AR and 527 in x39 for the hunt

Maybe not as sexy as 6.8 but a solid work horse

Yes/No?

Hank

I'm shooting a 30 Herrett in an AR15. It's a wildcat of course, and using 6.8 SPC brass loaded to higher pressure than the old Contender loads. Ballistics are roughly the same as the 300 Savage, or in between the 30/30 and 308.

I have a 308 AR too but the 308 platform is bigger and bulkier.

I vote for the 6.8 as a good alternative to the 223 in an AR15. It has less reliability issues than the 6.5 Grendel and shoots flat out to 300 yards. My personal 6.8 wears a 16" ARPerformance barrel and is the most handy and accurate hunting carbine I have.

The 6.8 will give you that range? That's pretty cool
Hank

"I'm shooting a 30 Herrett in an AR15."

Yondering,

I've looked at the 30 Herret; Which version are you shooting? Black Hole's, the HRT or AR Performances (which I don't know may be the same as one of the others?)?

Whose dies are you using?

And what kind of velocity (what barrel length & bullet weight)?

Thanks,

Jerry

Jerry,

Mine is an actual Herrett chamber, rather than a variation of it. The 30 HRT is the closest. The ARP version has a shorter throat, and BHW's version (30 American) has more capacity with the shoulder bumped forward. I just used a 30 Herrett reamer for mine though.

Regular 30 Herrett dies work with no modifications. With the Herrett chamber, you need to either neck turn the brass or open up the chamber neck as I did.

At some point I may bump the shoulder forward with a 30 American reamer for a little more case capacity, as the neck is long enough and shortening it won't hurt any.

I'm pushing the 125gr Nosler BT to 2740 fps, and a 150gr SP (Sierra I think) to 2500. This is from a 20" barrel.

6.8 SPC

The Herrett is a very hard hitting round out of an AR15 but it is a wildcat. The original 30 Herret pistol chamber had zero freebore. The lands start sloping up at just in front of the case mouth.
This is a little data including some pressure trace tests from the ARP 16" version.
Suggested loads-
125gr Sierra prohunter loaded to 2.240-30.5gr 1680=2610fps CCI 450 primer
125gr Nosler Ballistic tip loaded to 2.3"-30.5gr 1680=2680fps CCI 450primer
110gr Barnes TSX loaded to 2.295, 31gr 1680=2678fps
110gr Barnes TSX loaded to 2.295, 32gr 1680=2796fps
130gr MK319 bullet loaded to 2.295 30.5-30.7gr 1680=2600fps

The Hornady 125gr SST is not as accurate as the bullets above.

Added- Using SSA brass. Federal brass has .8gr less capacity.
28.5gr 1680 behind a 125 TNT hit 2500fps out of a 16" barrel.
29.5gr 1680-apx 2570- Very accurate with 125gr Speer TNT and Hornady SST
30gr 1680=2594fps--54925psi
30.5gr 1680 =2655 --57053 psi max(meaning do not try or use more powder than this)
30.5gr 1680 is pretty much max with 125gr bullets. The 125 Sierra prohunter hit 2600+- and the 125 Nosler hit 2680 with the same charge. The Sierra has more bearing surface, may be why it was slower.

Here is an interesting comparison between my current 308 Win and 6.8 hunting loads:

18" ARP 6.8, 120SST @ 2590, .400 BC:


24" 308 Win, 165GKHPBT @ 2630, .363 BC:

Ha! Agreed!

Similar BC's at similar velocities will have similar results regardless of how you launch them.

That's not what you get when you order a 30 Herrett reamer these days, in my experience. Of course, being a wildcat, there are a number of variations of it under the same name. My understanding was the original concept was throated for round nose bullets though, most of which require a little more freebore. The reamer I used matches that, with more freebore than your ARP barrels.

No AR at this time. I have all the parts and its in process again, only to use to track deer with my dog as a finisher.

The ONLY point in shooting a 300/221 IMHO is suppressed for quiet. Action noise ... makes noise... Same on my 10-22, wiht it I often hold the bolt closed when suppressed to make it like a bolt gun as I don't have a bolt thats threaded for a can yet.

50% of the other deer still run when I shoot suppressed.... and while I've yet to shoot more than one pig at a time with the bolt gun, I'm sure all pigs will run....so why make even more noise ALA AR?

I can run a bolt awful fast if needed.... not like an AR obviously, but years of match shooting and playing with bolt guns along the way in rapid fire strings you learn to run em fast, though I think I will add a knob to the 700 in 300/221.... will be going SBR with it as soon as I remember to fill the forms too, and will SBR the AR upper too....doesnt' take much barrel to get 900 or so FPS out of a 194 with a short tube.

Having shot pigs past 200, a couple of deer around 170ish, and a yote at a bit over 500, I forget the exact rangefinder reading, the X39 does just fine easily to 200 for me. I wouldn't even think of passing at 300 either...

So, you like 7.62x39 for hunting but see no use in supersonic 300 Blk loads... What am I missing?

I never said that I had any problem with the 300 BLK this is just another choice
I like the x39 also because its a great plinking round with a bit more punch. for plinking its a great value

Hank

Hank, Yondering's comment was directed at Rost. Rost has voiced his disdain for anything supersonic in the .300 B/O many times here.

6.8 SPC

My question was for rost.

I am in agreement with what you said, except I prefer the 300 Blk instead of the x39 for the AR platform, for a number of reasons. The ballistics are close enough to not matter for this discussion. the 6.8 seems like a great option too though, and ammo is getting pretty cheap (relatively).

Yes, RE the supersonic thing.

I like full cases of powder. Or I'd run x39 sub.

For that size round the X39 works just right at super and the 300 works just right or a bit too large of a case for subs.

So if I"m going to go super, i"ll just run the x39, and git a bit more speed out of the thing, and the ability to run a bunch of surplus if I had to for whatever reason.

Just my way of thinking, right or wrong.

I'm still not seeing it. 7.62x39 and 300 Blk supersonic loads do essentially the same thing, and 300 has several big advantages if you load your own.

You've said several times you see "no use" for the 300 supersonic. What does the x39 do for you that a supersonic 300 doesn't?

Just trying to understand something that doesn't make much sense to me...

no forming brass. cheaper and surplus ammo if you want to blast and if I'm going to go supersonic, I"ll take all that plus a bit of speed advantage to the x39 from what I've seen over the years.

Granted that may all have changed now... I know you can get formed brass for the 300/221, and its cheaper ammo now. But for years it was teh case.

if going super, why not take the speed advantage?

Yes the bolt is different... and requires a different mag, but other than that, and thats something I can deal with easily enough.

Given lets say a 125 grain bullet, what super sonic speeds are you getting out of the 300/221 these days?

A 16" AR will do ~2350 with a 125gr Nosler Ballistic Tip, in my experience. The better selection of .308" bullets is valuable IMO.

Making brass isn't a big deal for me, and it doesn't need to be fireformed. (Don't know if that's what you're referring too, but some guys still insist it has to be fireformed from 221 Fireball instead of sizing down 5.56 like everyone else.)

Factory 300 ammo is certainly more expensive, but I wouldn't know much about that, I've never bought any. Cost for reloading 300 is a little cheaper than x39.

It's not that both don't work well; my question was why the disdain for 300 supersonic when you're happy with x39 supersonic? There isn't enough ballistic difference to worry about.

when going supersonic I take all I can get... extra 100 fps is happily taken. Extends my range, helps with wind drift. At least thats my thoughts.

I didn't fireform my formed brass. It was just more work to form, cut off, trim etc... until I just bought some Lapua to see if it would be more acccurate than formed... have not tested yet. In an AR I would not waste the time.

Some of this is just like my thoughts on the suppressed rounds and not having an AR that way yet.... trying to get quiet, but you deal with action noise...why? there are obviously some good reasons, but at that point, I'm not so sure that going supersonic with a suppressor wouldn't be the better trade off.

BTW its not a disdain for the 221 round super, just that it doesn't make sense to me when I can grab the X39 stuff and run without any issues and get a bit more speed.

FWIW a loose buttoned bore my nephew has shoots ball x39 in a.308 diameter barrel just fine, and shoots 125 ballistics around an inch at the same time.

BTW are there other advanatages to teh 300/221 other than the .308/.311 issues?

Besides the larger selection of bullets, brass is essentially free if you form it from 5.56, shares all parts except the barrel with a 5.56 AR, and it uses less powder than the x39.

It makes a lot of sense in an AR. I wouldn't bother with it in a bolt gun though; it's too easy to get better performance with supers in other calibers, and for subs I'd rather have a 357 or other 35 cal.

I've not seen an x39 upper run with .311 bullets.

But as you point out it may be basically a wash...