6.5 Grendel vs. 6.8 SPC vs. .308
I have been looking at these calibers for several years now. I have read most everything I could get my hands on to help me figure out what would be the best “all-around” AR-15 caliber. I should specify when I say “all-around” I am considering: hunting (varmint to deer size), long range target and hunting, CQC or self-defense, cost per round, accuracy, penetration and “knock-down” power or ft-lbs of energy delivered.
I have read so many articles and there seems to be more “emotion” and “personal taste” than facts and ballistics. My goal here is to present what I was looking for several years ago before spending money on AR uppers. I have 5 different calibers of ARs and love most all of them (see my review of the 450 bushmaster) but I was looking for “one” several years ago and I know many people that are looking for just one upper to meet their many needs. Many people even consider some of the AR-15 calibers against an AR-10 (.308). I have compared many different manufactures of these three rounds with various bullet weights. They have all been fairly consistent. I chose to use Hornady for this comparison just because of their reputation and my experience with them. The ballistics I took from Nikon’s “Spot-On Ballistics Match Technology”. I also looked at Hornady’s ballistics however they only had info going out to 500 yrds. It still remained consistent with other info I have seen. I always say “the proof is in the pudding”. Take a look at the ballistics and look at the ballistic co-efficient (BC) for each of them.
6.8 SPC 120 gr Hornady SST (found as low as $.86 per rd for Hornady and cheapest (Remington) at $.79 per/rd)
Test Barrel (16") Velocity (fps) / Energy (ft-lbs)
MUZZLE100 200 300 400 500
2460/1612 2250/1349 2050/1120 1862/923 1685/756 1522/617
6.5 Grendel 123 gr Hornady A-max (found as low as $.88 per rd for Hornady and cheapest (WolfGold) for $.62 per/rd)
Rifle (16" Barrel) Velocity (fps) / Energy (ft-lbs)
MUZZLE100 200 300 400 500
2350/1508 2189/1308 2034/1129 1885/971 1744/831 1612/709
.308 155 gr A-max (found as low as $1.04 per/rd for Hornady)
Test Barrel (24") Velocity (fps) / Energy (ft-lbs)
MUZZLE100 200 300 400 500
2850/2795 2639/2397 2438/2045 2245/1735 2062/1463 1887/1225
I would have to say it’s a “no-brainer”. The 6.5 Grendel will outperform the 6.8 SPC in most every way. I have read arguments that the 6.8 SPC is a better CQC rd. This just kills me when I read “the 6.8 will outperform the 6.5 under 300 yards” “go with the 6.5 for long range hunting and the 6.8 for more knock down power”. REALLY…..Why?.......... Kinetic energy is almost EXACTLY the same from muzzle to around 300 yards with the same wt bullet. The difference is so small it is irrelevant. It would seem that there is little difference regarding accuracy at these distances as well (most would agree that the 6.5 always has a slight advantage for accuracy due to BC at any range). However, after 300 yards the 6.5 really takes the lead and the same goes for speed and accuracy. So 0-300 yards they are relatively equal. Look at 500-1000 yard distance and there is no comparison. Why would you not want to have both short and long-range capabilities? In fact, if you compare the 1000 yard ballistics of the 6.5 Grendel with the .308 it is shocking just how close the two are. The 6.5 is slightly faster but slightly less energy due to the lighter bullet. The sectional density is very impressive for the 6.5 so the penetration is most likely better than the .308. I am only making the comparison between a 6.5 to a .308 at “long” distance. There is little comparison regarding speed and energy less than 500 yards. Under 500 yards the .308 is far superior in both.
I have also heard that the 6.8 outperforms the 6.5 with shorter barrel lengths. Go to Hornady and compare the 6.8 SPC 120 gr SST vs. the 6.5 Grendel 123 gr A-max. The 0-500 yard ballistics for both are out of a 16” barrel and are very, very close out to 300 yards where the 6.5 takes the lead in both speed and energy.
What about cost? I have read many articles that supported the 6.8 over the 6.5 due to cost per/rd. The 6.8 has more companies that produce the cartridge however the cost per/rd can be found cheaper for the 6.5 (checkout ammoseek.com). I purchased 500 rds of WolfGold MPT for $12.50 box/20 rds. That is pretty cheap! Word is that Wolf is going to start producing steel cased ammo in 6.5. With the recent release of the “6.5 Grendel” trademark from AA, it is only a matter of time before more companies cash in on this caliber that has been “not so attractive” due to royalties in the past. Currently, I have only found ammo for the 6.5 in 2-3 different manufactures. My hope is that this will change as more people realize the capabilities and reality of this caliber. The cost per/rd from Hornady is about the same. Both are much cheaper than match ammo in the .308.
If you are into re-loading, the 6.5 has a very large selection. Hornady has 14 different selections ranging from 95 gr to 160 gr. The 6.8 also has 14 to select from based on .277 or 270. They both have a good selection for re-loading but currently the 6.8 SPC does enjoy the advantage in the variety of ammo available.
If I had to choose one of the three for everything from: CQC, combat/self-defense, hunting, target shooting at both short and long range, weight of ammunition and rifle, and cost for shooting……….. The 6.5 Grendel wins without a second thought.
I could not figure out why the 6.5 had not been adopted by the military and more embraced by the civilian population for years. Many wanted you to believe it was the lesser of the two cartridges. There were problems with the legal aspects related to name/trademark “6.5 Grendel”. It was a trademark/legal/royalties issue that kept a great cartridge from being produced by most of the mainstream AR companies. The GOOD news is that the 6.5 Grendel has been accepted by SAAMI and that Alexander Arms has agreed to release their trademark on the name "6.5mm Grendel". We should see in the next year a MAJOR growth of companies producing both weapons and ammo in the 6.5. I seriously hope the military will now take a second look at this cartridge for NATO. The history of the 6.5 is as long as it is impressive.
BOTTOM LINE………..do the research (should not take long) and see for yourself. This is a SUPERIOR cartridge for hunting (vermin to medium to large game), short and long distance target shooting, low recoil for younger shooters or faster follow up shots, and cost effective for shooting. If you are limited on “coin” and need to pick one upper to do it all, this is the one.