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Da..it, Don't shortchange me! 6.5 Grendel vs. 6.8 SPC

Discussion in 'Rifle Country' started by autobahndriver, Jul 19, 2004.

  1. I don't want another compromise round (6.8 SPC)

    The 6.8 SPC is a "limiting" cartridge in that it's effectiveness is less at longer range. :(
    I don't want another cartridge that limits me in some way.:mad:

    The 6.5 Grendel can be a good round for some of the long ranges we are now seeing in Afghanistan. :)
    Why go to a 6.8 SPC - good for short range - and then find ourselves wanting a good long range shooter as well as short range terminal performer?:confused:

    Energy delivered are similar between the 6.8 SPC and 6.5 Grendel at short range and they are similar sized bullets.
    At longer range 300+ meters, the Grendel significantly outperforms.

    Remember that our situations will continually change and we will find ourselves wanting.
  2. Ballistics Comparison:

    6.8 SPC / 6.5 Grendel
    Sierra 115 gr / 123 Scenar Lapua
    .340 BC / .542 BC

    2422 / 2427 fps at 100m
    1498 / 1609 ftlb at 100m
    +6.06 / +5.76 in drop at 100m
    1.20 / .90 in drift at 100m (10mph)

    1916 / 2102 300m Velocity
    938 / 1206 300m Energy
    0 / 0 300m Drop
    12.05 / 7.49 300m Drift

    1488 / 1803 Velocity
    565 / 888 Energy
    -52.41 / -43.73 Drop
    37.8 / 22.41 Drift

    ….and the 6.5 Grendel just gets better compared to the 6.8 SPC as range increases.
    At 1000m the Grendel still has 1222 fps Velocity and almost twice the energy as the 6.8.

    Both the 6.8 SPC and 6.5 Grendel weigh 11.5 lbs per 300 rounds.
    The 6.8 SPC and 6.5 Grendel have similar recoil (slightly more than a 5.56)
    Both the 6.8 SPC and 6.5 Grendel can be used with existing AR15 lower assemblies.

    The 6.5 Grendel is better on all accounts – why is there any argument???
  3. ChiefPilot

    ChiefPilot Well-Known Member

    Then use 7.62x51. It's got more short- and long-range energy than eithe the 6.5 or the 6.8, it's less expensive than either, and it's readily available. AR-10 type rifles are readily available as well, as are a number of bolt, pump, and even lever action rifles in the caliber. Problem Solved. :)

    I just don't understand the hoopla about the 6.5/6.8 rounds. If you want more than 5.56 has to offer, just get what you want - a 7.62.
  4. sumpnz

    sumpnz Well-Known Member

    I believe the hoopla is that the 6.5 gives you almost everything the 7.62x51 does, but with less recoil and less weight. Also, the 6.5 with the 144 grain bullets, actually outperformes the 7.62 beyond, I think, 400 yards thanks to it's really high BC.

    autobahndriver, do a search here on the 6.5 Grendel and you'll find all the info yuo ever wanted, and about every opinion possible expressed on the cartridge.
  5. Grump

    Grump Well-Known Member

    Well, 7.62x51 doesn't make sense militarily. The Grendel can give you at least equal wind drift, and even better, than M80 ball at extended ranges, with very little decrease in terminal energy and virtually the same trajectory.

    And M80 ball does that while using MORE powder, MORE brass, copper and lead, LARGER primers, and MORE shooter fatigue. Go to the better 7.62x51 loads like M852 and M118 LR and all those disadvantages become slightly greater, and in enough quantity to make a difference for strategic considerations (more shots per pound of metals ore, greater shipping costs per shot, and more weight on the Grunt for the same combat load of XXX rounds).

    The Grendel can make the promise of the M14 doitall compromise rifle actually attainable, with better downrange performance.

    What I want to know is whether the reported problems of "accuracy going to pot at pressures bringing the desired velocities" problem of the 6.8 have also cropped up for the Grendel. Anyone?? Anyone?? Bueller??
  6. Sam Adams

    Sam Adams Well-Known Member

    A great website related to the 6.5 Grendel is http://www.65grendel.com/

    Personally, I prefer the 6.5 Grendel vs. the 6.8 SPC based on ballistics. The biggest thing going for the Grendel is its BC - this is pure mathematics with which the SPC proponents can't argue. It is simply a better bullet, and the round itself has been optimized from a very accurate benchrest round so as to operate in the M16/AR15 family with minimal, if any, problems. If I could afford it, I'd have already bought either an upper or a whole rifle, together with reloading gear, brass and bullets. I also look forward to this round being developed for a boltie, as it is seriously accurate.

    However, the odds of either round being picked as a replacement for the 5.56 mm are small. The latter is considered "good enough" by those in logistics who aren't in combat, plus there is just a lot of inertia in any large organization (esp. government). I'd love to see either round picked, as both are far superior to the 5.56mm (the only reason for this round to be good is very high velocities, which aren't attained in the short-barreled rifles being handed out lately), but of the 2, the Grendel is better. JMHO.
  7. ChiefPilot

    ChiefPilot Well-Known Member

    True, but the 7.62 with 175gr bullets is better still. Check out the ballistics chart for the 6.5 Grendel - the 7.62 still holds the energy advantage at 1000m.

    For my own personal use - the amount of brass, power, and lead doesn't matter as I can buy 7.62 for far cheaper than I can 6.5 or 6.8. For the military, I'd just as soon keep them using the 5.56 and instead put the money towards something like this or this.
  8. sumpnz

    sumpnz Well-Known Member

    The differences in velocity and energy (for the 144 grain 6.5mm and 175 grain 7.62mm) past 600 meters are academic. Given that very few soldiers will take shots even that long I don't think the small differences really matter (it's only 10 ft-lbs difference at 1000 yards - variations from shot to shot can be bigger than that). Besides, I was intending to comapre against the M80 ball rounds (147 grain). I suppose it would be more appropriate to comapre that round to the 123 grain load for the 6.5. In that case, by 200 meters the 6.5 is going faster than the 7.62, and somewhere between 500 and 600 meters the 6.5 takes over in terms of energy. At 600 meters the 6.5 has a 6" and 10" advantage in drop and drift respectively.

    As far as cost goes, were the military to adopt the 6.5 Grendel it would drop in cost very quickly to about that of what 7.62 NATO currently costs. Right now it does not have the economy of scale working to its advantage.
    Yes, but we are mostly talking about the military use of the round. For them, weight is a very high priority. It was one of the big reasons they went from the .30-06 to the 5.56mm in the first place for general infantry use.
  9. JShirley

    JShirley Administrator Staff Member

    Hooah! Carrying stuff sucks. Lightweight ammo good. John smash!
  10. Preacherman

    Preacherman Well-Known Member

    Don't forget that a very, very important factor in the design process for the 6.8mm. round was that it had to be able to fit as many rounds as possible into a standard M16/AR-15 magazine. Thus, the cartridge is narrower than the 6.5 Grendel, and more of the former can be fitted into a standard M16 magazine than the latter.

    Makes sense, from a military point of view, no?
  11. sumpnz

    sumpnz Well-Known Member

    Preacherman - Well yes, but if they tooled up for 6.5 Grendel production they could just make slightly larger mags to fit the same number of rounds, and when they modified the existing mags, they could easily restrict those to training use only until they wore out, or sell them unmodified as surplus. So long as the AWB expires, and is not brought back in near term there would be no problem with that.
  12. TODD3465

    TODD3465 Well-Known Member

    As far as I know the 6.8SPC was develped with SOCOM and wide spread military use will probably be non-existant.

    However it would probably have a better chance at being adopted as it will be getting more exposure through actual combat use than the 6.5Grendel.
  13. sumpnz

    sumpnz Well-Known Member

    Well, considering how much better the 6.5 Grendel performed at Blackwater, I would imagine that SOCOM might be at least somewhat interested in field testing of that round too. Certainly if I were in charge of those decisions that would be my approach. Whether or not they actually do so is another matter entirely though.

    Personally, if I can ever scratch up the cash to buy an AR-15, and the cash for an upper in either 6.5 or 6.8, I would choose the 6.5. And if I had the cash for two uppers, I'd get one in 6.5 with an 18.5" carbine barrel, and one in 6.5 with a 24" or 28" match barrel. And if I really had too much money to spend on AR conversions, I'd probably go for a 50 Beowulf upper (more to frighten DiFi than anything else), and maybe some other calibers like 22lr (for cheap practice), or 9mm, 40S&W and 10mm (since I like the idea of pistol caliber carbines as companions to a sidearm). But I doubt I'd ever bother with a 6.8SPC upper. I just see much point (for myself) for such a limited round that is matched or beaten by the Grendel with very little lost on the compromises that are made.
  14. TODD3465

    TODD3465 Well-Known Member

    The makers of the 6.5 can blow their horn about Blackwater testing it all they please but the 6.8SPC round is what is being used by the military not the 6.5.

    Right now a major ammuntion company (Remington) is starting to crank out the 6.8SPC and they have 3 versions of the ammo that will be available to civilians pretty soon.

    Myself I don't have any personal interest in either one. Until the military actually adopts sometrhing new I'll stick to .223 and .308 in my semi-autos.
  15. sumpnz

    sumpnz Well-Known Member

    Yeah, and they're all 115 grains AFIAK. Just a matter of whether they are FMJ, soft point, or whatever.

    The big thing that I like about the 6.5 Grendel, regardless of military acceptance, is that it can take 90-144 grain bullets. That makes it much, much more versitle. The 6.8, which is basically a member of the .270 family, can only go up to 115 grains. If I wanted a .270 for hunting, I'd go with a .270 Wincester, which at least allows for bullet weights up to 150 grains (possibly higher, but that's as heavy as factory loads typically go).
    And, as I mentioned before, I think that's a mistake. When I'm king of the world all such idiocies shall be recitified. Until then, I'll pin my hopes on commercial success of the 6.5 Grendel. And let's face it, the 6.8SPC just will not compete in the market place based on its performance. I don't know what 6.8 uppers are going for, but even if the Grendel uppers were $200 more, I'd still bet on the Grendel winning the war for the wallets of consumers.
  16. Preacherman:
    The 6.5 Grendel will fit the same amount of rounds in the same magazine as the 6.8 SPC. There is only the thickness of a sheet of paper difference in case diameters!
  17. The military will be using the 6.5 Grendel as well. Spec Ops has great latitude in what they choose to use. Example: H&K SOCOM (MK23) was developed by military contract for US Spec Ops use yet various Spec Ops groups still adopted different pistols (Seals - Sig due to being more compact).

    Now if we could get a better round adopted for the rest of the military!

    I think the major selling point for the military would be one round to replace both the 5.56 and 7.62.

    The 6.5 Grendel performs very close to all 7.62 rounds in energy delivered but has better ballistics and lighter cartridge weight.

    I plan to get a personal 6.5 Grendel upper.
    I am promoting further testing of the 6.5 Grendel currently within the military.
    I will promote adopting the 6.5 Grendel within the military if use over the next couple of years does not show any problems.
  18. Ballistics of 6.5 Grendel compared to 5.56 and 7.62 NATO:

    6.5 Grendel / 5.56 NATO / 7.62 NATO / 7.62 NATO
    123 S.Lapua / M262 / M80 / M118LR
    .542 BC / 340 BC / .418 BC / .496 BC

    2750fps / 2600fps / 2700fps / 2500fps Muzzle Velocity
    1293ftlb / 1846ftlb / 2379ftlb / 2429ftlb Muzzle Energy

    2102 / 1957 / 2051 / 1971 300m Velocity
    1206 / 655 / 1373 / 1509 300m Energy
    7.49†/ 11.72†/ 9.48†/ 8.77†10mph Wind Drift

    1803 / 1521 / 1676 / 1661 500m Velocity
    888 / 396 / 917 / 1072 500m Energy
    -43.73 / -50.18 / -45.73 / -49.81 500m Drop in.
    22.41 / 36.76 / 29.03 / 26.44 10mph Drift

    1222 / 954 / 1063 / 1113 1000m Velocity
    408 / 156 / 368 / 481 1000m Energy
    -422.87 / -591.67 / -491.29 / -497.96 1000m Drop
    107.83 / 182.73 / 144.55 / 127.31 1000m Drift

    300 rounds ammunition weight:
    6.5 Grendel w/123 S.Lapua – 11.5 lbs / 300 rnds
    5.56 NATO M262 – 9.0 lbs / 300 rnds
    7.62 NATO M80 – 13.8 lbs / 300 rnds
    7.62 NATO M118LR – 15.0 lbs / 300 rnds
    6.8 SPC same weight as 6.5 Grendel

    *this is 20" barrel information - shorter barrels give a greater advantage to higher BC bullet and a case closer to short magnum in shape.
  19. ChiefPilot

    ChiefPilot Well-Known Member

    Source? *EVERYTHING* else I've seen acknowledges that a 175gr 7.62x51 load is superior to the 6.5 Grendel out to 1000m. If you have new information comparing factory loads, I'd be interested in learning more about it.
  20. The Ballistics table above is correct: Yes, when you consider terminal energy the the 7.62 M118LR round delivers more energy at under 1000m ranges than the 6.5 Grendel (superior as you stated above). The 7.62 NATO M80 is surpassed by the 6.5 Grendel at 600m+ in energy delivered.

    The 6.5 Grendel, on the other hand, is superior in drop, drift, and accuracy at all ranges.

    It is a trade-off:
    6.5 Grendel advantage 50% less recoil (7lbs vs. 14lbs)
    6.5 Grendel advantage higher BC, less drop, less drift, better accuracy.
    6.5 Grendel advantage less ammo weight.
    6.5 Grendel advantage can be used with existing M16/AR15 lowers.
    7.62 NATO M118LR advantage 19.8% more energy at 300m, 17.9% more energy at 1000m.
    7.62 NATO M80 toss up vs. 6.5 Grendel: 6.5 Grendel 9.8% more energy at 1000m, 7.62 M80 13.8% more energy at 300m.

    Not a bad trade in my opinion.

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