1stmarine
Member
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.
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.
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