AR-15 .223REM vs 6.8SPC vs 300AAC Blackout vs 6x45 vs 6.5Grendel vs 7.62x39...

[1stmarine]

I am doing comparative analysis of the following AR-15 calibers/upper options in terms of trajectory, accuracy, reliability, terminal effectiveness and pros&cons...

204 ruger
223 REM
6x45 / 6mm-223REM
7.62x39
5.45x39
300 AAC Blackout (I ordered a barrel for a new build but it is in back order so I am using the manufacturer data for now)
6.8SPC
6.5 Grendel

Varmint rounds
Initial testing shows .204 and .223 varmint rounds with low grain bullets are hard to beat in trajectory as they shoot very flat but also their potential for other applications is limited based on the characteristics of the bullets.


The .223 rem can be a great white tail round for moderate range. The military 62gr new penetrators show a huge improvement over the early designs. 75gr TAP (tactical) loads are extrevelly effective. Value packs of 55gr loads can be found below $300 for 1K rounds (Federal, UMC, AE, Priv, PMC, etc...)
Most of the new loads are very different from the loads in 1965 when the AR was introduced. TSX 70gr bullets and Swift 75gr bullets are devastating as many other that offer great hunting alternatives. The best bullets with the ballistic coefficients are mostly dedicated to match/target and require, along with some of the best hunting bullets, 1:8 and 1:7 rate of twist. Magazines has been adapted like DPMS VLD to allow single stack feeding of long OAL both in standard casing and AI offering.
High grain rounds offer good speed and retain energy better therefore carrying more lethal puch even well past the 400yards.

The 300 AAC Blackout
The round is a very easy conversion with lots of possibilities, including subsonic loads. I have not been able to test this barrel as I ordered a barrel for a new build but it is in back order so I am using the manufacturer data for now. This system is very simple as it only requires the barrel. Bolt, magazines, everyhing else is the same as the standard AR. The website lists an interesting comparative of some popular calibers but I think they missed (on purpose) some of the other very attractive alternatives. The information in the comparative is not 100% accurate.
http://300aacblackout.com/

The load is virtualy the same as the 300 wisper recently released by hornady....
http://www.hornady.com/store/300-Whisper-110gr-vmax

The round is hard hitting at close range and initial reports are of a very accurate round but it looses energy rapidly for mid range due to the poor ballistics of the round.

7.62x39
There are many great offerings from manufactures that will allow AR-15 enthusiasts to shoo the Russian classic military rounds. These rounds are not impressive ballistically but they offer a nice alternative to consume inexpensive surplus and value packs that make them a great round for plinkin and fun. A good quality SP or HP round can be a good hunting round for short-moderate range. Like the blackout at short range is very effective but in longer distances it suffers from the poor ballistics of the round.
This round shoots well out of the AR but it was really designed for the AK-47 system. This requires new barrel, bolt and also special magazines.

6.8SPC
The 6.8 Special was a response to the need to provide more terminal effectiveness, specially at closer ranges and deliver more energy on target.
The system was developed in a joint effort with special Operations advice to provide a platform with ammunition that handles very similar to the standard AR but delivers more power on target. It can also be very accurate.
While this is a nice improvement over the 223 round and even the Russian round it suffers from some of the same consequences of using a higher caliber lower grain type of bullet, it looses momentum faster. This can be also a great hunting round and some uppers are very accurate. Definitely a serious round.
It also needs a new barrel, new bolt and special/adapted AR magazines.

6x45 / 6mm-223REM
For me this is one of the best options for the AR-15. It uses a new 6mm barrel but the rest is the same, same bolt same magazines. The concept is old but very simple, neck up a .223 case to 6mm and then you land in one of the best bullet departments there is for both the target and hunting shooter.
It also makes it legal in those places where (for an inexplicable reason) the .223 rem is not allowed for white tail hunting.
The 6x45 provides a 20-30% improvement over the parent .223 rem case and makes it flat shooting, hard hitting, far reach round.
The round is extremely accurate and it won many matches back in the late 60's and early 70's before the BR round came along.

6.5 Grendel
This round uses an improved version of the PPC cartridge. It offers the possibility to launch extremely good bullets at decent speeds making an
excellent target and hunting round. This round doesn't shoot as flat as other more exotic casings but the bullets can travel far due to the high ballistic coefficient and stay supersonic delivering very good accuracy. The terminal effectiveness of the round is a very nice improvement over the original AR round and it has a very nice following from enthusiasts and special purpose use.
This system uses new barrels and it needs new bolt and special magazines.
It makes it along with the 6x45 a great alternative for those shooters that want to reach further while retaining energy due to the very good bullets that can be used.

There are other awesome offerings that I will summarize int his post like the 6mmAR, 6mmAR turbo, and some thumpers like the 50 bewolf, 450 bushmaster, and 540 socom but I just wanted to get started with some of the maybe most popular options and that I have been able to shoot.

This post is for interested people to learn about the different options and not to demote, criticize but to learn about possibilities so we do not end up in one of the threads like 9mm vs. 40cal, AR vs. AK, Shotgun vs rifle, MINE VS YOURS. All those senseless unfunded arguments that teach nothing and lead nowhere. Every round, firearm, tactic has a purpose and some advantages and disadvantages over others so we cannot and should not compare apples with oranges but learn how those options work so we can make the best choice based on our needs, likes and dislikes.

I will add some of the actual test results as time allows.

Cheers,
E.

 

[longdayjake]

No offense but your analysis isn't much good.

Do you have experience with ANY of these cartridges?

 

[1stmarine]

There we go...
Why is not good. I have been shooting them all and some of them for the last 30 years in the service and after I retired. Provide a question or an evidence why the data is not good.
Just in a respectful way. I hope you understand.

 

[longdayjake]

Okay. First. It looks like an advertisement for 300aac. Why no links to info on the others?

Second, the 6.5 Grendel is one of the most flat shooting AR calibers out there and with a 24" barrel and the right bullet it will shoot flatter than most .308 match loads.

Third, it feels like you have disdain for 6.8 and 6.5 and 7.62 and displays an obvious bias to the 6x45.

Also, the .300aac doesn't have poor ballistics. It has low velocity.

 

[1stmarine]

My approach to things is that I want to learn from you or anyone, so lets do this if you want...
I am sorry if my comment came out as the grendel no being a good round. It is a great round no doubt.
Lets go one by one in detail. I can tell you the ones I have tested so please provide the ones you have tested yourself (not manufacturer or some other data). As I said in my post I don't have the ACC yet but I used the published data and the manufacturer seems to differ from other published data in their comparative so we have to be fair and this is the best way.
They all are great rounds but different purposes probably.

I give you one of the spreads that I have. I could never replicate the speed published by Adams arms w/o stepping into the red. My friends have the same problem but it is very close.
Fill out bellow what you have from your data...

My Data
Round______Barrel___Bullet_______BC.___ SD____Speed_____100yrds(Speed/Energy/Drop)__300yard_____________600yards
6.5 Grendel___24"____123 scenar__0.527__??_____2590______2414/1591/2.71______________2086/1188/27.00____1650/744/127.40
.223REM_____20"____69gr SMK___0.333__??_____3071______ 2762/1169.4/1.9____________2195.4 /738.4/20.8____1466.4/329.4 /110.2

Your data
6.5 Grendel 24" ??? ???? ?? ??? speed/energy/drop
6.8
300 ACC
....

I am not bias towards anything but I have to obviously highlight some of the differences I found in my testing. As it happens I was testing the 6x45 and .223 REM high grain loads last weekend. The other data is from last spring so I might need to go back and review or test again.
Lets talk just facts that are the bullets tested, the spreads and the hard math that way there is no confusion.
I will post more data below for other rounds. IT takes time to review and bring into a chart.

 

[longdayjake]

I'm sure your data is fine for you, but you are just like anyone who has their favorite caliber. You like the 6x45 and it shows. Hard to do a good evaluation of others when you really only care about the one. I have found that its best to do an evaluation on one at a time and not put them all in one thread. Especially if you are only going to do a single paragraph eval on something.

 

[1stmarine]

I have no one but many "favorite" calibers.
You asked me if I know the calibers and I tested them. I said yes.
Provide some data if you want so others can learn from facts.
I cannot write a thread for each one as with some I have more experience (like the .223 REM) and with others less but I think the assesments are acurate and whether they need new bolts, magazines or not. I want to have a good summary but please feel free to correct any misinformation I have or to extend those paragraphs based on your results not bare opinions.
This is an open collaborative thread.

 

[Boanerges57]

i would like to say I like your brief summary of these rounds. I didnt feel this was a blatant plug. It was )as you stated) the only round you havent used and a link to manufacturer data.
6.5 is a fine round when fired out of 16-24" barrels as it was designed for.
Dont take every notion of another round being decent as an attack on the grendel.
I am building a grendel range rifle right now. If I were building something for HD I would probably go for 450 bushmaster or 50 beowolf.
If I were intent on hunting at ranges of <400m I would be looking into a 6.8 spcII.
There are myriad options and opinions when it come to AR chamberings, It is somewhat discouraging when everytime someone gives an opinion it is taken as an assault on everyone elses pet round.
If you are going to say something, be productive at least; give some data to back up what you have to say.
I can say ".300 aac cant penetrate a pair of jeans at 100m" because i can sit all day and pull statements and factoids out of my @$$. It doesnt make it true and it doesnt make it helpful either.

Also lets also at least try to include barrel lengths when we discuss performance. It is incredibly helpful to do so.

-thanks for an informative yet brief bit of info 1stmarine-

 

[longdayjake]

So we all agree with the assertion that the 6.5 grendel is not a very flat shooting round? Its okay to ask me to post data to disprove his statement but simply because he posted the OP he gets the benefit of the doubt? I mentioned the things about his evaluation that I felt were poor and misleading. If he wants to back up his claims HE needs to prove them. Not just say them.

Is there another round for the AR that can be double stacked in a mag and be shot to 1000 yards with less drop?

 

[lobo9er]

These rounds are not impressive ballistically

This is your quote describing 7.62x39.

how so?
I'd say in multiple applications this is a pretty impressive round. You say 223 can be a great white tail round, but I'd say x39 would make a better white tail round wouldn't you?

 

[68wj]

For your comparison criteria, this is the only AR caliber I have data on. I shoot 5.56 too, but only shoot loads for function and not performance right now.

6.8 SPC, 110 Grain Nosler Accubonds (BC .370), 18" lightweight barrel

Trajectory,
My handloads with H322 are getting a conservative 2630 fps (which happens to be identical to SSA factory ammo claims). +2.3" @ 100, O" in @ 200, -9.7" @ 300.

Accuracy,
I have plenty of room to push the bullet faster, but this load is giving me sub-MOA easily. Long ranges in windy conditions are not ideal.

Reliability,
No problems to report.

Terminal effectiveness,
Minimum expansion velocity at 1800 fps puts bullet performance just shy of 400 yards. No game personally taken by me yet, so I can't claim any kills other than 1 gal milk jugs (though, those are still fun ).

Pros&cons...
Easy to build with many sources of 6.8 parts and support available. I pair barrels with bolts anyway so the new bolt was a non-issue for me. Great accuracy in a lightweight, low-recoil package with plenty of game taking power. Ammo is easy to find in my area, online, or at my loading bench.

I give up 5 rounds per mag v/s 5.56 (not an issue when hunting as I have a 5 rd mag limit). There is no cheap, milsurp or russian berm killing ammo available. Good ammo is comparable to other calibers.

Other shooters are also favoring the lighter weight premium bullets for hunting. The 85 TSX and 95 TTSX have gotten great reviews. I am awaiting Nosler's 85 eTip that is to be released later this year as well. There is also a ladder of 120gr SSTs waiting on my dresser for a range trip.

 

[68wj]

So we all agree with the assertion that the 6.5 grendel is not a very flat shooting round? NO

Its okay to ask me to post data to disprove his statement but simply because he posted the OP he gets the benefit of the doubt? Seems dubious to me

I mentioned the things about his evaluation that I felt were poor and misleading. If he wants to back up his claims HE needs to prove them. Not just say them. Concur. Or, at least give the disclosure that there is no 1st hand experience to back up the summary and is based on internet hearsay

Is there another round for the AR that can be double stacked in a mag and be shot to 1000 yards with less drop? AR15? Maybe a wildcat but nothing I know of

Cartridges of the World

 

[rsilvers]

The information in the comparative is not 100% accurate.

What data is not accurate? Give one example.

 

[451 Detonics]

The original concept of the .300 Whisper was for use in suppressed firearms...hence the name. AAC just took the all R&D JD Jones did and added a mm to the case length to avoid being sued. This alone make the cartridge unique from the others in your comparison as none of them were designed with suppression as the main objective.

 

[rsilvers]

Ridiculous. SSK has no patents on the 300 Whisper(R) and there would be no basis for a lawsuit even if it were copied exactly. Every final dimension we selected has a specific purpose. I cannot even say things were 'changed' as we did not even know what dimensions SSK used. We simply started from scratch with a 221 Fireball case and made it an optimal 30 caliber.

As for ballistics, I have shot it at 600 yards with an AAC 16 inch lightweight upper. I hit the 3 inch X-ring.

 

[1stmarine]

lobo9er,
I didn't mean to discredit any caliber here. I have used them all. I love the 7.62x39 FMJs for all my AKs although I do not use it for hunting.
Yes the 7.62x39 is a great cartridge for hunting for close to moderate range.
I don't reload this one as the good brass and quality bullet selection is restricted but definitely there are some good quality brass loads out there.
The bullet drops substantially after 200 yards but with a good rifle and quality brass load it can be very accurate and a little bit more can be squeezed out of this great round.
It is widely used for deer hunting around the world but folks must be conscious about the range limitations.
Cheers,
E.

 

[1stmarine]

68wj,
The 6.8SPC is a great round too with great capabilities. No doubt about that.
Do you have more data on those reloads?
I have been measuring the spreads out of the following factory loads that all have been awesome loads by the way:

Hornady 6.8mm SPC 110 gr V-MAX that yields average 2540fps out of a 16" barrel. I Also tested a few of boxes of the 6.8 SPC 110gr Barnes TSX and also the Nosler AccuBond you mentioned all with very similar results.
All very accurate.

These are the results that I am getting at 300 yards..
Speed 1851
Energy 837
Drop 30.09

After that the bullet starts to fall rapidly. Is this consistent with your results?
Thanks.

 

[1stmarine]

Boanerges57,
I have the 300 AAC on back order as they told me on the shop now they are flying off the shelves. The reason I am going with this one is to try some of the suppressed subsonic loads that people have shown so accurate and reliable. Just for fun, nothing serious.
Regarding the Grendel it is a great system. My buddy got one with the 26" Lothar Walther barrel that is printing .40MOA all day long.
What I cold not understand is why the 300 AAC blackout website lowered the numbers on the 6.8SPC and Russian rounds. I get higher spreads on my 6.8upper (16") or any of the standard AK 47 even using the standard loads in 16" barrel. And they do not even mention the Grendel, the 6x45 uppers or any others.
I guess to make the blackout look better? It is not necessary no doubt is a great round for what the purpose is...
Here in the middle of the page.... http://300aacblackout.com/

Please feel free to post any information you have in your loads or spreads as this might be useful to others. I am trying to put a workbook with all the spreads together so people can see just as a reference depending on purpose, budget or any other considerations. And of course, I included the barrel length. You might have missed it.



Round_________Barrel___Bullet_______BC.___ SD____Speed_____100yrds(Speed/Energy/Drop)___300yard______________600yards
6.5 Grendel______24"____123 scenar__0.527__??_____2590______2414/1591/2.71_____________2086/1188/27.00______1650/744/127.40
.223REM________20"____69gr SMK___0.333__??_____3071______ 2762/1169.4/1.9_____________2195.4 /738.4/20.8____1466.4/329.4 /110.2
6.8 SPC ________16"____110V-Max__0.370__??_____2540_______2294.5/1285.8/2.9___________1850.8/836.6/30.1_____1296/410/155.86
300 AAC _______16"____123gr______0.265__??_____2315_______1994.1/1086.0/3.6___________1442.1/568.0/40.5_____N.A./N.A./249.5
6x45(6mm-223)__20"____90gr SGK___0.376__??_____2762_______2508.6/1257.5/2.4___________2048.1/838.2/25.1_____1466.4/429.7/128.0
6mmAR Turbo____20"____105 VLD___0.493__??_____2907_______2706.6/1707.9/2.2___________2333.2/1269.2/21.5____1838.7/788.2/101.7
7.62x39________16"_____123grSST__0260__??_____2350_______2020.4/1114.8/3.5___________1454.6/577.8/39.5______N.A./N.A./245.1

I added a few other tests results. As I mentioned for the 300AAC I am using the manufacturer published data. Also for this and the russian
I don't have speed and energy at long range as I customized my charts with Break speed at 1300fps at which point I discard any accurate calculation and the
bullet is on ground or heading straight to it probably.I also adjust the retardation coefficient based on the Mayewski constant in all my ballistics charts.
As you know there is no one single Ballistic coefficient for one bullet. Most manufactures do not advertise this. Sierra does a good job and provides
a more accurate information regarding their bullet's ballistic coefficients.

I hope this helps.

Cheers.
E.

 

[68wj]

After that the bullet starts to fall rapidly. Is this consistent with your results?
Thanks.

I am currently limited to a 100 yd range and have been unable to hunt for the past year so I don't have real-world data beyond that and a chony at 10' (never had game past 100 yards anyway). Hornady's online calculator lists 300yd data as 1962 fps and 940 ft lbs with the Accubond.

The loads are for a SPCII chamber (as the SAAMI chamber would be like buying the latest muscle car and not getting the V8). There is still have room for more velocity but that speed gave me great accuracy with my barrel. Others are getting great results with Rl 10x and AA2200. H322 is good for accuracy and moderate speeds across the spectrum of 6.8 bullet weights (85-120).

 

[1stmarine]

68wj
I do believe the 6.8 with a 120gr would make a great alternative to many bolt rifles even for bigger game at moderate range.
When I saw SSA had a TSX and Nosler in 110 I had to try it and even I have not used that one on game I am getting amazing accuracy.
Based on my experience with any TSX from .223 rem to .338 lapua, it doesn't matter the grain or the caliber they are devastating. The nosler partitions the same story.
I don't have a problem with a bigger drop as I am very picky to make sure I map the bullet drop to the scope/sights, update the charts and never touch the upper again.
I tell people you can train drop and long range with a 250dollar rifle in a 200 yard range. ie: Savage bolt BBL in 22LR with high quality loads shooting at 50-100-150 and 200 yards requires some
understanding of ballistics to make scope adjustments, wind, etc... Need a decent scope though. that always.

Do you know what barrel did hornady lists? I have my chart at the following at 300 yards (see I updated above too) 1850.8/836.6/30.1
So Hornady seems a bit optimistic (maybe lab conditions) but plausible nevertheless.

 

[rsilvers]

What I cold not understand is why the 300 AAC blackout website lowered the numbers on the 6.8SPC and Russian rounds. And they do not even mention the Grendel, the 6x45 uppers or any others. I guess to make the blackout look better?

I generated those numbers. I did not lower any of them. The 6.8 data was right off Hornady's website.

I did not mention the Grendal because it is a proprietary wildcat. I did not mention 6x45 because it is a wildcat.

 

[1stmarine]

It makes sense initially but why to leave out some others, specially good performers. They all are "wildcats", aren't they?
the fireball necked up to 30 caliber is a wildcat.
The grendel is based on the PPC / 220 russian
the 6.8 is based on the .30 remington
... and the list goes on....

I am not trying to discredit the 300 AAC, I think is a great round with a lot of hard word to bring it to specs but just stroke me that the comparative
is so short and restricted.

 

[rsilvers]

300 AAC BLACKOUT is not a wildcat. It was submitted to SAAMI in June of 2010, and on January 17th, 2011, SAAMI voted it in as a standard cartridge. Neither is it proprietary. Any ammo company can make ammo royalty free and any gun company can make guns, royalty-free. Cartridge and chamber drawings are available from SAAMI.

 

[1stmarine]

I know what SAAMI is. You could also say in your comparative SAAMI vs proprietary/wildcats I believe.
I am sure I will enjoy the 300 blackout when the barrel arrives and I will be buying some rounds to play with it and the loads.
I might post this comparative in wikipedia.

 

[rsilvers]

It seems like we have two different definitions of wildcats. You are using the term to mean any cartridge which was based on another cartridge. By your definition, the 270 Winchester is a wildcat as it is based on the 30-06. I am using the term to mean any cartridge which is not standardized by industry organizations such as CIP or SAAMI.

Comparison charts based on wildcats should be approached with extreme prejudice as there is no SAAMI protocol test barrel data and the velocity is not likely to be achieved when tested in an actual pressure test barrel within normal pressure limits.