Building a new AR, either .308 or 6.8

[86K5]

Been building 5.56 ARs for a while and feel I have a good handle on the quality aspect of what I need but I'm trying to decide what would be the better option. .308 or 6.8. I have been leaning towards the .308 but with the different variations in parts, I'm wondering if the 6.8 would be a better option. I will be using it for everything one would use a 5.56 for but I would like to take medium sized game out to 500 yards. Maybe target shoot past that. I know both would do what I'm asking just fine but I guess it's the variables that are teetering me away from the .308. Should I take the plunge and just build the .308 or play it safe and build the 6.8? Also, if I choose the .308, what options do I have that have the most "options" I guess, or the least amount of hassle to build as far as parts availability...

[Grand58742]

I think you'll get more out of a .308 myself especially at distance. Plus the availability and variety of ammo in .308 would be the kicking factor. 6.8 runs cheaper, but has limited selection and can't always be found. You can walk into any Walmart and typically find .308.

Only suggestion would be to go with the DPMS/Knights pattern magazines if doing a .308 build. Not that the Armalite pattern mags aren't good, just expensive.

[Failure2Stop]

It is a lot easier to get a home-brewed 6.8/6.5 to run.
Stepping up to .308 is a significant change to the applied physics of the operating system.
There is only 1 7.62 AR that has an actual Gov TDP, everybody else is doing their own thing, making parts interchangeability/compatibility a tough beast to nail-down.

[SomeOtherGuy]

but I would like to take medium sized game out to 500 yards. Maybe target shoot past that. I know both would do what I'm asking just fine

Actually I don't think a 6.8 is realistic to take medium sized game at 500 yards. The best performing factory load for distance, Hornady's 120gr, has only 1500fps or 595 ft-lbs at that distance, and is dropping quickly - meaning your range estimation and wind dope have to be absolutely perfect. Personally I would say 500 yards with a .308, for humane hunting, is an experts only proposition, and that expert would be starting with 200fps more muzzle velocity and a bullet BC of about 0.5 instead of 0.4 or less. People who regularly hunt at 500 yards typically use much flatter shooting cartridges than .308, much less than a 6.8 SPC.

With that past - for a 6.8 SPC you can build an AR15 to a high quality level with quality components available from multiple sources. For a .308 caliber AR, you have to pick one proprietary platform, figure out what other parts will work with it, and build a truly frankenrifle that will probably be unique in the world. Things seem to be getting worse instead of better for standardization of .308 AR stuff, since Colt didn't really follow anyone else's pattern, DPMS has a gen2 that is almost completely different from their first generation, S&W has a platform that this similar but not identical to the KAC/DPMS gen1 pattern, many companies are coming out with receiver sets that mostly seem to vary slightly from anything else, etc. Even though the concept is AR, the implementation is completely proprietary, much like typical bolt-action rifles. If you want to build something I would do a 6.8 or something else that fits into the AR15 pattern. If you want a .308, I would pick an existing commercial rifle to start with, and customize from there.

[Onyx Z]

Should I take the plunge and just build the .308 or play it safe and build the 6.8?

I think a better question would be should you take the plunge and build a 6.8 or play it safe with a .308?

I would go .308 for two reasons:
1. More ammo availability
2. .308 uses the most popular caliber bullet

The 6.8 uses an obsolete parent cartridge, the .30 Remington. And as said earlier, the ammo availability is not nearly that of the .308. And due to the lack of parts interchangeability with .308 pattern AR's, I would purchase rather than build. But I would get one of the major platforms if you ever do want to rebarrel the rifle.

FWIW, I don't have a 6.8, but I did think about it and do some research before choosing 300blk.

[constructor]

I think a better question would be should you take the plunge and build a 6.8 or play it safe with a .308?

I would go .308 for two reasons:
1. More ammo availability
2. .308 uses the most popular caliber bullet

The 6.8 uses an obsolete parent cartridge, the .30 Remington. And as said earlier, the ammo availability is not nearly that of the .308. And due to the lack of parts interchangeability with .308 pattern AR's, I would purchase rather than build. But I would get one of the major platforms if you ever do want to rebarrel the rifle.

FWIW, I don't have a 6.8, but I did think about it and do some research before choosing 300blk.

Why would you look for an obsolete parent cartridge when, SSA/Nosler, Federal, Hornady, S&B, Barrett and Remington make brass for the 6.8?
Kind of like looking for a Ma bell rotary phone to convert to a cell phone isn't it? New 6.8brass runs around $50/100 and LWRC sells once fired Federal for around $225/1000
I don't think many cartridges work well on game at 500 yds but 300 is easy enough, maybe 400 if the conditions are perfect.

[Onyx Z]

Why would you look for an obsolete parent cartridge when, SSA/Nosler, Federal, Hornady, S&B, Barrett and Remington make brass for the 6.8?
Kind of like looking for a Ma bell rotary phone to convert to a cell phone isn't it? New 6.8brass runs around $50/100 and LWRC sells once fired Federal for around $225/1000
I don't think many cartridges work well on game at 500 yds but 300 is easy enough, maybe 400 if the conditions are perfect.

Whoops, forgot to add this to my original post.

If the manufacturers stop making 6.8 brass due to lack of sales, you're screwed. Worst case scenario, you could convert a number of cases to .308. Not so with 6.8.

From my experience, 6.8 is not very popular among the masses. Likelihood of 6.8 ceasing production? Slim to none, but I bet the .308 will around forever due to it's popularity.

[VIP3R 237]

If you are set on building the 6.8 is the easier beast to build. The ar10 platform is a bitch to match up parts as not everyone follows the same specs as FS2 is saying. Hell even take down pins are different from mfg to mfg. If you are going to go with the ar10 platform I would suggest purchasing a complete rifle.


It is a lot easier to get a home-brewed 6.8/6.5 to run.
Stepping up to .308 is a significant change to the applied physics of the operating system.
There is only 1 7.62 AR that has an actual Gov TDP, everybody else is doing their own thing, making parts interchangeability/compatibility a tough beast to nail-down.

[weggy]

I feel the 6.8 to be in the decline, again, the answer to a question no body asked.

[Failure2Stop]

I feel the 6.8 to be in the decline, again, the answer to a question no body asked.

Yup.
And for long range, there are better answers readily available.

Sent from my VS980 4G using Tapatalk

[jmnielsen]

I feel the 6.8 to be in the decline, again, the answer to a question no body asked.

I've not seen that at all... The opposite actually. I have no worries about brass, either. There is plenty of manufacturers it just sells like hot cakes- similar to 22lr ammo. We don't see the .22 going any where now do we?

With that said, I would never try and shoot medium sized game at 500 yards with my 6.8. I'd shoot at coyotes or smaller with it out to probably 400 depending on the ammo used. I'll also add that while the 308 is definitely awesome, I'd just skip it and go 6.5CM or .260. You could build either one in the larger platform.

[weggy]

I've not seen that at all... The opposite actually. I have no worries about brass, either. There is plenty of manufacturers it just sells like hot cakes- similar to 22lr ammo. We don't see the .22 going any where now do we?

With that said, I would never try and shoot medium sized game at 500 yards with my 6.8. I'd shoot at coyotes or smaller with it out to probably 400 depending on the ammo used. I'll also add that while the 308 is definitely awesome, I'd just skip it and go 6.5CM or .260. You could build either one in the larger platform.
I never said it would disappear completely, ammo will get scarce, some manufactures will possibly drop it completely and ammo will always be way more expensive than 5.56. The only way it could compete would be if the Military adopted it. And that ain't gonna happen.

[Regalkismet]

I feel the 6.8 to be in the decline, again, the answer to a question no body asked.

From everything I've read it's just the opposite... I'm sure Constructor will chime in but from stats I've seen it's one of the top selling calibers for the AR15.

[CMW]

ammo will always be way more expensive than 5.56. The only way it could compete would be if the Military adopted it.

That applies to virtually every hunting round out there. Whatever the origin of the 6.8 was, it's most useful application today is for hunting medium-sized game inside 300 yards.

I built a 6.8 because CA hunt regs require the use of rifles chambered in something larger than .240, and I didn't want to lug around a 308 pattern AR.

[jmnielsen]

I never said it would disappear completely, ammo will get scarce, some manufactures will possibly drop it completely and ammo will always be way more expensive than 5.56. The only way it could compete would be if the Military adopted it. And that ain't gonna happen.

I know you didn't say it will disappear completely. I'm just confused on why you think ammo will get scarce when actually more manufacturers are making ammo for the 6.8... Obviously it will be more expensive than 5.56. Can you name a round that is not a widely adapted military round that is cheaper than 5.56? It would never be cheaper than 5.56 anyways as it uses more brass, powder, lead, etc. That would be like saying .45 would be cheaper than 9mm.

[yellowfin]

Maybe implied but not stated is of course that if you've put any money into the existing lowers you have, not having to spend that again by simply adding a 6.8 upper is really, really nice. $200-300 on a Giessele trigger, $70-100+ on a nice Magpul stock, etc. adds up quick. Put that savings into brass and you've got all the ammo you'll ever need. Something that the naysayers say about the 6.8 about higher ammo cost and less available completely neglect to account for is that you don't have to be shooting the 6.8 round every time--again, if you're shooting the same trigger, stock, etc. you're practicing with the same gun. I'll gladly shoot 5.56 rounds at paper, coyotes, and woodchucks then 6.8 rounds at deer and hogs, and maybe .22LR at squirrels and rabbits.

[bruin]

I built a 6.8 because CA hunt regs require the use of rifles chambered in something larger than .240, and I didn't want to lug around a 308 pattern AR.
I don't think this is quite right, see section 353:
http://fgc.ca.gov/regulations/current/mammalregs.aspx

Basically in CA you can use any caliber centerfire cartridge to take big game. In condor country, bullets must be lead-free. We can take this sidebar to PM to avoid cluttering this discussion.

No argument here however, that 6.8 would be more effective, all else being equal.

[constructor]

Whoops, forgot to add this to my original post.

If the manufacturers stop making 6.8 brass due to lack of sales, you're screwed. Worst case scenario, you could convert a number of cases to .308. Not so with 6.8.

From my experience, 6.8 is not very popular among the masses. Likelihood of 6.8 ceasing production? Slim to none, but I bet the .308 will around forever due to it's popularity.

I think you may be surprised how many 6.8s are floating around out there. I get calls or emails from dealers every day asking if we can supply them with barrels and bolts. I really wish we could get 500 barrels produced every week. ATK is producing military grade ammo for it. They only load for 308, 5.56 and 6.8. and a few pistol calibers.
At this point there's a much bigger chance of WSSM, RCM, WSM, RSAUM and many more disappearing.

[constructor]

If you want to go to a 308 platform look at the DPMS GII. They are much lighter than most, around 7lbs. Similar to the AR12s I built in 2009.

[constructor]

I feel the 6.8 to be in the decline, again, the answer to a question no body asked.
How many companies that manufacture the 6.8 have you surveyed?

[tmwtrfwler]

I have a 6.8 from ARP (Constructor's place) and it's bad to the bone. I also have an LMT (which I recently got and had issues with....of which LMT promptly fixed) .308. Both are incredible guns. Both are great for deer hunting. one is lightweight, one is heavyweight. Both are fun, both function flawlessly, and both kill deer. my solution was to get both calibers b/c I simply wanted to. if it were strictly limited to one I would go the 6.8 all day. it drops deer DRT, the gun is soooooo much lighter, and it's interchangeable lower with the 5.56 / 300 blackout is a huge advantage over the .308 (although I could get different uppers for the MWS too but those are other high $ calibers).

I have a gun problem. I guy many calibers b/c I like guns. so there's no perfect answer.

just re read your post and saw the 500 yard desire. if that's a routine situation then the .308 is it. but within 300 the 6.8 IMHO

[benthughes]

I have a LMT MWS .308 and a Noveske 13.7" upper on a Mega lower in 6.8 SPC. There are definitely pros and cons to both, many have been mentioned here. I would probably not take the LMT hunting as it's heavier than I'd like to hump around, that being said there are lighter .308 pattern rifles out there. The .308 is a more effective at all ranges at the cost of more but easily manageable recoil. AR-10 rifles are expensive and there are tons of proprietary bits and pieces out there. I'd probably go with a production .308 as opposed to building my own but my comfort zone lives in the realm of the AR-15.

If you decide to build a rifle in 6.8 you have the piece of mind of being a barrel and bolt change from a 5.56 or .300 something or other. IMO the 6.8 takes the capability of the AR-15 platform to the edge of what it's capable of. I don't particularly get the appeal of .300, especially for those who don't reload.

[Nightvisionary]

If you want to hunt out 500 yards with an AR 15 based rifle the only practical way is with a 6.5 Grendel. The 6.8 just doesn't have the ballistic coefficient to get there.

[Regalkismet]

If you want to hunt out 500 yards with an AR 15 based rifle the only practical way is with a 6.5 Grendel. The 6.8 just doesn't have the ballistic coefficient to get there.

Personally I don't think either of them are ethically 500 yd hunting rifles for medium sized game.... The 6.8 spc II with loads like the SSA 140gr. Berger will run with if not better than most any 6.5 load especially at 500 yrds...But this is not a 6.8 vs Grendel thread....

[hk_shootr]

Was in this same situation a few years ago. Built a 6.8, it ran very well. If I were limiting myself to 300m, I would stick with the 6.8. The 6.8 is a great intermediate cartridge, fills the void between 5.56 and .308.

In the end I dumped the 6.8 and stuck with the .308 Win. A wee bit of research and you can easily build a reliable .308. After running a few Armalites, I moved to the LMT........perfect platform for my needs.

[Symmetry]

500 yards is a bit far for practical 6.8 use. Sure you can target shoot with it at that range, but you will lack several desirable attributes that you want in a long range cartridge. You want a bullet with a high ballistic coefficient(over .400), a high sectional density(over .230), while traveling as fast as possible. The longer the bullet takes to get there and the more prone it is to wind drift, the harder it is to hit a dynamic target. From a practical standpoint in hunting or sniping as a lone shooter, you want a cartridge that will have no more drop than 3ft, and a drift of no more than 1ft. Even bullets like the 6.8 120gr SST will suffer almost double those detriments at 500 yards. There's a reason why most sniper schools now days favor the .300 Win Mag or .338 Lapua Mag for ranges over 600m. If you want a cartridge that is easier to use at 500 yards, and will actually have decent terminal effects at that range.......the .308 is a no brainer. 300 yards is about what I am comfortable using a cartridge that is in the 2500fps range which is what the 6.8 is for hunting medium to large game. Now if you want to talk 5.56 vs 6.8 for long range target shooting, I prefer the 5.56 as it shoots flatter.

[HD1911]

Just out of Curiosity, but why does it have to be with a Semi-Auto? If you're looking to take a shot on Game out to 500 Yards, you will normally only get that one chance.... hence a bolt gun, would be appropriate for this tasking. The 6.8 SPC cartridge flat out sucks in the External Ballistics Department, btw.

A simple $600-$1,000 Factory bolt gun could fulfill this role you're looking for. Then you can actually pick from a slew of well suited Cartridges, easily have Sub-MOA capability, Enough Impact Energy, and Utmost Reliability.

And I have to ask, what is your Experience with LR Shooting? Alot of these types of questions and recommendations come up.... and I have to ask, do you know your Limits? Because I do believe Ethics come into play when trying to factor all this in... whats the Probability of a 1st round Impact at 500 Yards, on say a 10" Circle.... How accurately are you going to be able to Judge the Wind, in the Field? Hopefully you'd be using a good LRF to get your Distance down. How Capable is your rifle and ammo combo? What if you have to take a less than desirable shot from a crappy position?

Just cause some folks can hit a Steel Plate at 500 Yards with a certain cartridge, on a nice sunny day, at the range, with many tries, being able to adjust accordingly....does not mean you will be able to do it under adrenaline, out in the field, in less than desirable conditions, on your most likely first and only round.

Not to dig on you, but if you're asking these types of questions, you most likely don't have what it takes, at the moment, to make a clean kill on an animal at that distance. Again, no offense.

Just food for thought...

[Symmetry]

Just cause some folks can hit a Steel Plate at 500 Yards with a certain cartridge, on a nice sunny day, at the range, with many tries, being able to adjust accordingly....does not mean you will be able to do it under adrenaline, out in the field, in less than desirable conditions, on your most likely first and only round.

+1 to that.

In the late 1990s we qualified on MP5s out to 50yrds. With 6x magnification I was able to hit a silhouette repeatedly at 300yrds with 147gr match ammo. Just because you can hit something at long range with a particular caliber, doesn't mean that it will do much damage to the target. I have taken a lot of white tail with a M1 Carbine, but it is a 50 yard hunting rifle. Sure I can hit silhouettes with it at 400 yards on a good day.......but it loses a significant amount of terminal effectiveness beyond 50 yards.

[Nightvisionary]

Personally I don't think either of them are ethically 500 yd hunting rifles for medium sized game.... The 6.8 spc II with loads like the SSA 140gr. Berger will run with if not better than most any 6.5 load especially at 500 yrds...But this is not a 6.8 vs Grendel thread....

I would mostly agree with your first statement although several hunters have taken elk with the 6.5 Grendel at 400+ yards including Mark Larue. The SSA 6.8 load with that Berger 140 with a BC of around .487 is a single loading from a single source that is unavailable. While almost every 6.5 mm bullet suitable for class 2 game or larger meets or exceeds that BC. If the OP wants to shoot up to 500 yards with a non 308 based AR the Grendel is going to give the better performance at range. If you are limited to a mag length cartridge you won't be able to escape the mathematics associated with the better ballistic coefficient of 6.5 bullets over 6.8 bullets.

[Artifact]

No experience with 6.8, so 308 AR for me.

[gunnut284]

I would rather build a 6.8 (or 6.5) but if I wanted a .308 I would buy factory. I went with .308 (in the M&P10) but that was due largely to already being invested in other .308 rifles as well. An AR15 platform rifle can be lighter and handier but the .308 will have a bit more horsepower. If you want to build and don't have other .308s then I would go 6.5G (6.8 would be ok too but I would prefer the 6.5).

[Regalkismet]

Fact is performance wise for the 6.8 spc II and Grendel in their actual ethical hunting range is very very close to each other, especially when taking into account necessary velocity for proper bullet expansion, with the 6.8 having the edge in many cases when using spec II Ammunition under 300 yds..... which is the range that probably 95% of hunters actually hunt within.... Again right tool for the job... If you are hunting at 500 yds neither is the right caliber no matter who has taken what at what distance.... You could make claims like that for any caliper.... Unless you reload the 6.8 has far more factory ammo options available.... I think Midwayusa carries like 24 different types of factory 6.8 ammo and only 6 types of Grendel ammunition.... 6.8 seems to have a lot more industry support than the Grendel and no bolt breaking issues.... Also 6.8 parts are more widely available..Like John Paul says velocity is king under 300 yds and I agree... . OK... Back to topic... I just had to reply as I hate when threads that have nothing to do with a caliber are used to try and make another caliber look superior when it has nothing to do with the thread and really isn't the case.

[Nightvisionary]

Fact is performance wise for the 6.8 spc II and Grendel in their actual ethical hunting range is very very close to each other, especially when taking into account necessary velocity for proper bullet expansion, with the 6.8 having the edge in many cases when using spec II Ammunition under 300 yds..... which is the range that probably 95% of hunters actually hunt within.... Again right tool for the job... If you are hunting at 500 yds neither is the right caliber no matter who has taken what at what distance.... You could make claims like that for any caliper.... Unless you reload the 6.8 has far more factory ammo options available.... I think Midwayusa carries like 24 different types of factory 6.8 ammo and only 6 types of Grendel ammunition.... 6.8 seems to have a lot more industry support than the Grendel and no bolt breaking issues.... Also 6.8 parts are more widely available..Like John Paul says velocity is king under 300 yds and I agree... . OK... Back to topic... I just had to reply as I hate when threads that have nothing to do with a caliber are used to try and make another caliber look superior when it has nothing to do with the thread and really isn't the case.

You make some good points, I will grant you the 6.8 has more factory offerings but if you do reload the 6.5 has a significantly better selection of bullets since it is not limited to short lower B.C. bullets. We also need to remember this is not a 300 yard or less discussion. The OP stated he wanted to hunt medium game to 500 yards. The ideal cartridge for that function doesn't really matter because we can all agree it's not a 6.5 Grendel, 6.8 SPC, or 308. If the 6.5 Grendel is not to be considered then that leaves the .308 because the 6.8 just doesn't have what it takes to get to 500 yards on game. In fact if I was going to keep it under 300 yards I would probably stick to a 300 Blackout.

[Regalkismet]

You make some good points, I will grant you the 6.8 has more factory offerings but if you do reload the 6.5 has a significantly better selection of bullets since it is not limited to short lower B.C. bullets. We also need to remember this is not a 300 yard or less discussion. The OP stated he wanted to hunt medium game to 500 yards. The ideal cartridge for that function doesn't really matter because we can all agree it's not a 6.5 Grendel, 6.8 SPC, or 308. If the 6.5 Grendel is not to be considered then that leaves the .308 because the 6.8 just doesn't have what it takes to get to 500 yards on game. In fact if I was going to keep it under 300 yards I would probably stick to a 300 Blackout.

No offense but I'd take a Grendel or or 6.8 over a 300 BO if hunting at 300 yds.....trajectory of the 300 is pitiful compared to the other two at that range... Seriously? ... Especially if you are using point blank range.... IMHO 300 is best for a Suppressed sbr rifle... That's where it shines... Beyond that the 6.8 and Grendel have it all over the 300 BO... Especially if you are talking hunting medium game at 300 yds... You really lost me on that. Maybe it's because I value using point blank range... Idk. If I'm looking to hunt medium game at 500 yds give me Atleast a 6.5 Creedmoor, 260 or a variety of other larger calibers.

[jmnielsen]

You make some good points, I will grant you the 6.8 has more factory offerings but if you do reload the 6.5 has a significantly better selection of bullets since it is not limited to short lower B.C. bullets. We also need to remember this is not a 300 yard or less discussion. The OP stated he wanted to hunt medium game to 500 yards. The ideal cartridge for that function doesn't really matter because we can all agree it's not a 6.5 Grendel, 6.8 SPC, or 308. If the 6.5 Grendel is not to be considered then that leaves the .308 because the 6.8 just doesn't have what it takes to get to 500 yards on game. In fact if I was going to keep it under 300 yards I would probably stick to a 300 Blackout.

I can honestly say I would never recommend a 300BO for 300 yards and under hunting scenarios. You would have to lob a bullet there and it probably won't even have enough velocity to expand at 300 yards. 6.5mm bullets are numerous and many with a very high BC, which is why I would go with a 6.5CM or 260 over .308 in that platform. If I'm gonna go 6.5, I'm not going to mess with a grendel. It is a neat caliber but just not a practical hunting rifle (IMO).

[Nightvisionary]

No offense but I'd take a Grendel or or 6.8 over a 300 BO if hunting at 300 yds.....trajectory of the 300 is pitiful compared to the other two at that range... Seriously? ... Especially if you are using point blank range.... IMHO 300 is best for a Suppressed sbr rifle... That's where it shines... Beyond that the 6.8 and Grendel have it all over the 300 BO... Especially if you are talking hunting medium game at 300 yds... You really lost me on that. Maybe it's because I value using point blank range... Idk. If I'm looking to hunt medium game at 500 yds give me Atleast a 6.5 Creedmoor, 260 or a variety of other larger calibers.


I should have prefaced my statement a little better. At under 300 yards there is not the huge difference in performance between the 6.8 and .300 Blackout. The charts below compares SSA's published data for their 6.8 110 Sierra Pro Hunter at 2585 FPS vs a .300 Blackout 125 grain Sierra Pro Hunter at 2300 FPS. Neither loads are cherry picked. There are better and worse performing loads for both cartridges( Example, 300 Blk Barnes 110 grain TTSX blue tips gives me 2500 FPS with a standard 20.0 grain load of H110 which is below max). The idea that 300 Blackout is only useful as a suppressed SBR is parroted frequently by those who have never used it. The funny thing is you never hear anyone say that about the 7.62x39 M43 round through an AK yet they are nearly identical. With the Blackout zeroed at 200 yds a top of the back hold over will put the bullet in the vitals at 300 yards. It's not that difficult.

If you are only going to shoot at ranges under 300 yards I don't see the justification for investing in a system that requires special magazines, bolt, and expensive brass all for a roughly 15% increase in performance. For over 300 yard shooting I completely agree with you which is why I am going to build a 6.5 Grendel

http://i59.tinypic.com/23plaa.jpg http://i61.tinypic.com/120ikvb.jpg

[Nightvisionary]

I can honestly say I would never recommend a 300BO for 300 yards and under hunting scenarios. You would have to lob a bullet there and it probably won't even have enough velocity to expand at 300 yards. 6.5mm bullets are numerous and many with a very high BC, which is why I would go with a 6.5CM or 260 over .308 in that platform. If I'm gonna go 6.5, I'm not going to mess with a grendel. It is a neat caliber but just not a practical hunting rifle (IMO).

In a 300 Blackout Barnes 110 grain Blacktips will expand to almost 400 yards with a 16 inch barrel. The Barnes TAC X SBR bullet will expand to 350 yards. However most bullets will expand to around 200 yards.

[constructor]

In a 300 Blackout Barnes 110 grain Blacktips will expand to almost 400 yards with a 16 inch barrel. The Barnes TAC X SBR bullet will expand to 350 yards. However most bullets will expand to around 200 yards.

Bill Wilson hunted with both the 300 and 6.8. Ask him which he thinks does a better job of putting game on the ground and which he had more run offs with.

[Regalkismet]

I should have prefaced my statement a little better. At under 300 yards there is not the huge difference in performance between the 6.8 and .300 Blackout. The charts below compares SSA's published data for their 6.8 110 Sierra Pro Hunter at 2585 FPS vs a .300 Blackout 125 grain Sierra Pro Hunter at 2300 FPS. Neither loads are cherry picked. There are better and worse performing loads for both cartridges( Example, 300 Blk Barnes 110 grain TTSX blue tips gives me 2500 FPS with a standard 20.0 grain load of H110 which is below max). The idea that 300 Blackout is only useful as a suppressed SBR is parroted frequently by those who have never used it. The funny thing is you never hear anyone say that about the 7.62x39 M43 round through an AK yet they are nearly identical. With the Blackout zeroed at 200 yds a top of the back hold over will put the bullet in the vitals at 300 yards. It's not that difficult.

If you are only going to shoot at ranges under 300 yards I don't see the justification for investing in a system that requires special magazines, bolt, and expensive brass all for a roughly 15% increase in performance. For over 300 yard shooting I completely agree with you which is why I am going to build a 6.5 Grendel

http://i59.tinypic.com/23plaa.jpg http://i61.tinypic.com/120ikvb.jpg

I think I said 6.5 Creedmoor..... Not Grendel.... For hunting at those ranges. Also I would suggest that anyone that is going to hunt at 300 yds is probably going to use the ammunition that gets the most out of their rifle and just like you said the load you chose for the 6.8 is not a spc II load and basically mediocre.... Clearly a spc II load is going to offer much better performance.... And again best tool for the job would be the 6.8 even with the examples you posted but if $15 magazines and a $80 bolt keeps you from using the best tool for the job than the logic is lost on me... As for brass cost... This is for hunting not plinking so I'm not sure how that plays into it as all your examples are using factory ammo... Not reloads.... And I'm sure 300 is cheaper to reload but let's be realistic.... Do you really use your 300 to plink? And if so how much actual ammo would you use? I'm pretty certain the difference is a mole Hill, not a mountain.... But I use my 5.56 or my 22 to plink.....

[SomeOtherGuy]

This has kinda degenerated into an alternate-AR15-caliber debate, which has only happened like 10 million times in the last decade. The far more important point is that anyone* looking to ethically take medium game at 500 yards needs a .308 Win as a minimum, and would be much better off with something like a .260 Rem / 6.5 Creedmoor or something hotter still like a 7mm Rem Magnum or 7mm WSM. The .308 Win, 260 Rem and 6.5 CM are all readily available in AR-10 style platforms, so if you want to go that route, decide between a more economical .308 Win AR, or a flatter shooting 6.5mm AR option (not Grendel).

*if you have decades of hunting experience and regularly rank High Master in competition, there might be a few more options for you, at the fringe. You would still be better off with a .260 Rem or similar.

[Nightvisionary]

Bill Wilson hunted with both the 300 and 6.8. Ask him which he thinks does a better job of putting game on the ground and which he had more run offs with.

Any information gained would be anecdotal and of dubious value. Bill Wilson is a highly skilled gunsmith and salesman. He has a vested interest in selling as many 7.62x40 WT (Wilson Tactical) rifles as he can. For that reason it would be foolish for him to say anything positive about the 300 Blackout (7.62x35) for fear of his cartridge becoming the 41 Action Express of the 30 cal AR world.

The best standardized test medium we have is 10% ballistic gel. If you look at the FBI protocol 10% gel tests performed at Brassfetcher.com you will see that the 6.8 and 300 Blackout performed to a statistical dead heat in the tests. The Blackout was slightly handicapped in that it was tested at a velocity equivalent to a 50 meter impact while the 6.8 was tested at muzzle velocity. Both penetrated about the same distance and both expanded to about the same size.



http://i62.tinypic.com/2uopc1g.jpg

http://i60.tinypic.com/2n72xcm.jpg

[constructor]

Any information gained would be anecdotal and of dubious value. Bill Wilson is a highly skilled gunsmith and salesman. He has a vested interest in selling as many 7.62x40 WT (Wilson Tactical) rifles as he can. For that reason it would be foolish for him to say anything positive about the 300 Blackout (7.62x35) for fear of his cartridge becoming the 41 Action Express of the 30 cal AR world.

The best standardized test medium we have is 10% ballistic gel. If you look at the FBI protocol 10% gel tests performed at Brassfetcher.com you will see that the 6.8 and 300 Blackout performed to a statistical dead heat in the tests. The Blackout was slightly handicapped in that it was tested at a velocity equivalent to a 50 meter impact while the 6.8 was tested at muzzle velocity. Both penetrated about the same distance and both expanded to about the same size.


gel isn't pigs.

[Nightvisionary]

gel isn't pigs.

Well when they come out with a standardized repeatable pig let me know;). Until that time terminal ballistic research and cartridge/bullet performance is primarily compared using 10% ballistic gel. It's not the end all be all but a whole lot of pigs have been DRT killed with 300 Blackout as well.

[constructor]

Well when they come out with a standardized repeatable pig let me know;). Until that time terminal ballistic research and cartridge/bullet performance is primarily compared using 10% ballistic gel. It's not the end all be all but a whole lot of pigs have been DRT killed with 300 Blackout as well.

I thought we were talking about hunting performance. I don't know anyone that hunts gel. Experience in the field with both will tell the story and anyone can do it.

[gunnut284]

gel isn't pigs.

actually it is...

[kittyhawk]

I hunted this last season with a 6.8. I killed three deer, a shit load of pigs and four coyotes. All with Hornady 120sst. My closest shoot was 45 yards on a yote and produced a golf ball size exit wound. Longest was a 145 pound doe at 320 yards. I heart/lung shot her, the sst blew up and shredded her heart and lungs, she went aprox twenty yards.
All the other kills were made between 85 & 150 yards all were clean humane kills. I really like the 6.8 from the ease of the build, nothing special needed but bolt, mags. I am going to try some different ammo types this summer to see what my barrel likes, I really want to find a bonded round that my gun will shoot as well as the sst.

[constructor]

actually it is...
LOL, We don't have gel running through the woods where I hunt. Texas, Ga, Fla, Tenn or Colorado. Gel doesn't run, it just sits there waiting to be shot and then wiggles a little. Give it a heart, pea sized brain, the ability to fear, strength and a little tough hide and see if that changes things. What you guys choose to hunt with does not effect how my hunt ends. I don't care what you hunt with.

[Symmetry]

There are a lot of high power rifle loads that will penetrate into the 12-18" range in 10% ballistic gel with full expansion. There are a lot of pistol rounds that will do similar levels of physical damage to a gel block. However, we know with certainty that that particular pistol round is eclipsed by the rifle round when field tested on game. Gel has a hard time measuring how much tissue is actually torn in the temporary cavity stretch, and how the extent of that stretch generates additional incapacitation levels which allow the game to bleed out in place.
http://i1159.photobucket.com/albums/p637/scottomega76/riflegeltestanalysis_zpsfa2a08b8.jpg (http://s1159.photobucket.com/user/scottomega76/media/riflegeltestanalysis_zpsfa2a08b8.jpg.html)

My longest kill on a bull elk was approximately 450 yards with a Weatherby .270 Mag with 150gr SP. During field dressing there was your typical entrance and exit holes, however the heart and lungs were shredded from the TC. I have had similar experiences with magnum rifle calibers, or rifle calibers at closer ranges with medium to large game. Velocity is very important, in addition to bullet construction, SD, BC,.....etc to get more than just low end rifle wounding effects.

[Symmetry]

There is only 1 7.62 AR that has an actual Gov TDP

Who is that?

[Failure2Stop]

Who is that?

KAC

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