6.5 Grendel V.S. 7.62x51 500yds & Beyond........ Questions......

[Christopher67]

Can someone here that knows more about BC than I, tell me IF what this poster from another forum is saying is true or false?

I imagine if it were true, it would be being looked at right now. In order for Grendel to out perform 762, a 24in barrel is needed

762 M80 has 158in of drop at 600m (147gr) from a 16in barrel
6.5 Gren has 172in or drop at 600m (123gr) From a 16in barrel

6.5 Grendel performance just isn't there. That's why the AMU developed the .264 USA, Its would 6.5 Grendel should have been.

Heres the link to the thread/post:

http://www.survivalistboards.com/showpost.php?p=15729377&postcount=120

The thread was started here: http://www.survivalistboards.com/sho...d.php?t=759977

So IF someone here has some solid facts to either prove or disprove what hes says is true or false, that would be greatly appreciated. I'm working on another build & would rather have a better BC weapon to hunt with. Thanks!

IF this is the wrong section to post this in, i apologize.

[pajasonc]

There are many loads where the 308 will best the grendel. For instance with Noslers 168 accubond long range a 24" 308 will start a .597 bc bullet at 2750. There isn't a grendel load that really competes well with that load. Thing is your going to get significantly more recoil and still have to deal with a heavier rifle. To me the grendel shouldn't be compared to a full size rifle cartridge. Its the best thing going that fits in a ar15 platform. And for punching paper it can come pretty close to the 308 which is impressive considering the case capacity. But its still not a full size rifle cartridge, its one hell of a intermediate round.

[Kswhitetails]

I get a kick out of the debate of 308 vs Grendel. Who came up with this? When was the Grendel ever intended to compare to the full-length cases of 7.62, 6.5CM, .264USA...? That comparison is laughable, mainly because for what the Grendel is, it competes pretty damn well given the disparities in case size and platform limitations.

But what difference does that make? Pick an average guy, sit him at a bench and ask him to throw 200 accurate 308 loads to 600m. Then, ask him to give you 200 more from the Grendel. Then ask him if he wants to come back tomorrow and do it the other way around. You'll see real quick that the arguement is over, that the Grendel is awesome after all, and that there is no real reason to belittle the little 6.5 lightweight from the back church pews...

The reason Grendel is so great isn't because it out performs any other cartridge (of which there are a few); But that it's performance speaks for itself. Especially when it starts doing things that an AR15 platform based weapon shouldn't be able to do; and with authority! I have watched guys next to me shooting the Sig 716, or a 7.62 AR10 while I'm shooting my Grendel. I'm hitting that same plate of steel at 200, and just as hard, and I'm putting rounds on faster, more repeatedly, and with the same DING and swing as their MUCH louder, more blastiferous, more mule-kicky 7.62. I have had guys on more than one occasion ask to shoot, and afterward they ALL say that they can't wait to look into Grendel. Again, not because it's better, but because it is every bit of what they want in their rifles, even if they're dialing in another minute or two of angle. (The fun part comes when they pick it up off the bench, and compare the size and weight to their ar10, and sigh...)

The real kick is that they never mention wind deflection at these ranges and beyond. Its always that easily calculated drop number... It makes me wonder just how much shooting folks have done when they fail to account for the deflection because windage is almost always the harder call, and a general advantage to the smaller diameter, higher SD projectiles. But I digress...

Back before Grendel entered my stable, I once watched a guy with a brand new ar10 show up with three 20 round mags. He proceeded to load up all three mags with his American Eagle 175s and proceeded to blast away. He had some kind of 3-9 on it, which should have told me more than it did... He got through that first mag, into the second; had it printing about 12 inches, and was flinching so bad that he moved a couple inches on one trigger break and the round didn't even go off... and quit. He looked red faced, was obviously upset, and after someone asked him why, he said that this particular rifle was obviously jacked "because it shouldn't kick that hard". He bought a great weapon, bought great ammo, bought great magazines, and still failed to enjoy his new gun. All because he wasn't ready for the recoil associated with his fancy new 7.62 patrol.

I'll be honest, ever since the first time out, I never looked forward to shooting dad's 1903. The first two clips were great, but after that it was like a punishment to stay on at 200.

When I do get Dad to try the Grendel, I hope to do so on one such 03 Springfield day. And to witness the smile when we move to 400 for the first time, watch him repeat steel with Grendel, and to allow myself a snicker as his grin grows, and he at last understands the JOY of the surprise in the authority with which the Grendel slings its projos onto target at range.

It's not a 308 or .264USA. Fine. The guy's right. But I think you will have a lot more fun with your Grendel at reasonable distance than most will ever see with a 308. And let's remember, inside 500, Grendel kills as well as any large rifle cartridge. (Disclaimers galore, IMHO, YMMV, IIRC, etc...)

[rwh]

I have a 28 inch grendel that can shoot a 130 gr berger at 2570 fps, and a 308 palma rifle that shoots a 155.5 gr berger at 2950 fps. I compared the ballistics with the calculator at berger bullets site. At 1000 yards the grendel drops 37.3 MOA. The 308 drops 30.1 MOA. However with a 10mph cross wind the grendel has 8.6 MOA of drift and the 308 has 8.7 MOA of drift. That seems fairly comparable. Note that I am shooting 155.5gr bullets at 1000 yards from a 308 purely for sport. There are better bullets for 308 that can trim a couple of MOA off of that wind drift. I don't worry about drop if I know the distance. Wind drift is what matters and I think the grendel is arguably comparable to a 308 shooting a palma load at 1000 yards.

[StoneHendge]

Throwing the debate aside, he uses M80 for an example for 7.62. Ask him for a picture of his 600 meter groups with M80 before engaging further. I once read a barrel review where a guy said he got consistent 3" groups with Lake City ball - at 300 yards! I hope he bought a lottery ticket that day. Then ask for a video of him doing this at 750 yards with an AR10.

https://youtu.be/kJTsAVhFwGk

I guarantee you that this would never happen with my P308 with its best handload

[LRRPF52]

Red flag #1: Inches being referenced with meters.
Red flag #2: Drop being considered with no mention of drift

I'm getting 5 mils drop at 600yds for a 147gr FMJBT from a 16" barrel at 2600fps (M80 ball - I've fired boat loads of this in my life BTW).

More importantly though, I'm getting 1.9 mils of drift at 600yds, which sucks pretty bad. 697ft-lbs of energy

16" 7.62 NATO Carbine, 147gr M80 at 2600fps
600 1461fps 697ft-lbs 5 mils drop 1.9 mils drift

For a 16" Grendel with a 123gr SMK at 2450fps:
600 1581fps 682 ft-lbs 5.1 mils drop 1.5 mils drift

I colored each area where the particular data favored one cartridge over the other. Look how close the energy numbers are BTW after the Grendel started 150fps slower.

Guess what the most important factor in getting hits at 600yds, or even 300yds and farther is? Not drop, not energy, not speed....

If .308 was such a great cartridge, I'd still be shooting it in my personal assortment of blasters, as I've owned many, shot many for years, but no longer do other than what people bring to a course if I need to troubleshoot the gun when a shooter isn't hitting anything.

If I go to the .264 USA case capacity, magazine length, new receiver set, totally new rifle that doesn't exist other than the prototypes the AMU built, you know what all that effort gets me with the exact same bullet? Drum roll...............

1.4 mils of drift at 600yds vs 1.5 from a 16" Grendel, working with at least 5,000-8,000 less psi in the Grendel, vs. a need for new mag pouches, new mags, new receivers, new RDT&E program for the rifle, etc. It has 4.4 mils of drop with that same bullet at 600yds, but I'm going to hold or dial for drop anyway based on a known. Believe me, I like all the flat trajectory I can get. So what about the 107gr SMK from a 16" Grendel?

600yds 1665fps 659 ft-lbs 4.3 mils drop 1.5 mils drift

I normally don't compare Grendel to 7.62 NATO with a 147gr FMJBT because it just isn't nice, so I use one of the better target bullets out there, namely the 175gr SMK, which is a great performer from the .308 really. From a 16" SR25 EMC, you're going to be about 2430fps with M118LR (175gr SMK .488 G1 Litz BC).

This is why you hear me say a 123gr from the Grendel flies like a 175gr SMK from a .308, as the ballistics program models and what I actually see through the spotting scope match up pretty well. A 175gr SMK might edge out a 123gr SST or AMAX in wind drift, but not a 123gr SMK or Scenar, and unless the .308 is custom spun with a tight twist pipe, it starts falling apart for gyro stability past certain ranges, whereas Grendel with tight twist does not.

The difference is that one fits in the AR15, has half the recoil, you can spot your shots easily without a dedicated spotter, carry way more ammo, fight the close fight with the gun, and the other doesn't support those well at all.

[Kswhitetails]

Now, now, if you can't say anything nice...

I found myself actually laughing out loud. The wife was startled. I'm glad you piped up, LR.

[Kilco]

Numbers and ballistics aside, I find that my 16" Grendel shooting the 123 ELD-M at 2460 and my 20" 308 shooting 175 SMK at 2590 are so similar out to 800 yards it's eerie.

I enjoy shooting and carrying the Grendel more because it's quite literally half the weight, half the recoil and half the powder.

[Christopher67]

This is the info i was looking for, thank you much appreciated!

[rabiddawg]

Man this looks like a koolaid party.

Too bad it is all true and mirrors my experience. Especially the big grin after I let someone get behind one of my Grendels.

[just_john]

Yeah, but..... And to consider, you can go shoot a Grendel all day long and then go pitch a baseball game with no discomfort. Try to do that after shooting the 7.62 all day!!!

[LRRPF52]

Every time I pull the trigger on a 16" 7.62 NATO carbine that someone has brought to one of my courses or someone lets me shoot at the range, each cycling of the action and loss of sight picture rings in my head like this:

"Bang...So glad I have Grendel. Bang-SO Glad I have Grendel. Bang....Da** this sucks. Bang...Who thought this was a good idea? Bang...To think that this was my dream gun one time. Bang...I can hear my impacts, but sight picture has come way off target each time-asa that me or another shooter? Bang....Gotta love that muzzle concussion and FOV disruption."

A lot of 147gr FMJBT M80 is all over the place at 600yds, especially from a SCAR with a factory trigger. When I was competing with .308 Win., I was shooting the 155gr Scenar as fast as I could because at the time, we were accepting the stated BC of it being in the .5s, which turned out to be way inflated. A lot of us made that choice over the 175gr SMK based on the stated BC alone, when it turns out that the 175gr SMK has a better BC, bucks the wind better, holds its energy a little better. A 155gr Scenar was all over the place in normal wind conditions at 800-1000yds for me and my friends even from top-end rifles with top end barrels, top-end shops, top-end glass. The 155gr Scenar smokes a 147gr FMJBT all day long, with one exception being the German MEN stuff. That ammo is match-grade perfection, very fast, superb brass, super consistent bullet, way flat like a .260 Rem, but nowhere near the wind deflection of a 6.5mm.

For those that are die-hard, 7.62 NATO, 1930s-1950s regressive thinking (from decades of .276 Pedersen, 6.5x55, 6.5x54 M-S progress), that MEN ammo is wonderful TGT ammo.

Even guys shooting Creedmoor or .260 Rem can't put the round count onto a plate at distance as fast and easy as I can with a little 18" or 20" Grendel. I have them all, and there is a certain amount of atmospheric and particulate matter disturbance that happens with muzzle blast, requiring a lag time between shots to let the dust settle and the atmosphere to equalize.

I see a distortion of the air around the muzzle that obscures the target when I break the shot through one of the larger volume cartridges, especially when rapid-firing or wanting that fast follow-up shot, even at altitude. You can see what I'm talking about at 0:29 seconds into this video:

[stanc]

I get a kick out of the debate of 308 vs Grendel. Who came up with this?

Grendel fans were the originators of this idea.

[stanc]

I'm getting 5 mils drop at 600yds for a 147gr FMJBT from a 16" barrel at 2600fps (M80 ball - I've fired boat loads of this in my life BTW).

More importantly though, I'm getting 1.9 mils of drift at 600yds, which sucks pretty bad. 697ft-lbs of energy

16" 7.62 NATO Carbine, 147gr M80 at 2600fps
600 1461fps 697ft-lbs 5 mils drop 1.9 mils drift

For a 16" Grendel with a 123gr SMK at 2450fps:
600 1581fps 682 ft-lbs 5.1 mils drop 1.5 mils drift

I colored each area where the particular data favored one cartridge over the other. Look how close the energy numbers are BTW after the Grendel started 150fps slower.

I normally don't compare Grendel to 7.62 NATO with a 147gr FMJBT because it just isn't nice...

More importantly, comparing 6.5 GREN 123gr SMK to 7.62 NATO 147gr FMJ is apples vs oranges. Should be comparing 6.5 FMJ to 7.62 FMJ.

Wolf 100gr FMJ (???? BC)
Prvi 110gr FMJ (0.407 BC)
Norma 120gr FMJ (0.428 BC)

...so I use one of the better target bullets out there, namely the 175gr SMK, which is a great performer from the .308 really.

Which is perfectly appropriate for comparisons of sniper ammo, but gives inapplicable data for comparing infantry rifle/carbine/machine gun ball ammo.

[LRRPF52]

Grendel fans were the originators of this idea.

It's actually valid in my experience. You can handload some really high BC, heavy .30 cal bullets that will compete even with a .260 for wind drift nowadays, but your trajectory is pretty high, recoil takes you solidly off sight picture, so follow-ups aren't anywhere near as fast.

The most common cartridges in the .308 in both hunting and target though have less hit probability in my experience, even watching shooters who have a lot of quality trigger time with a .308 Win.

Put a Grendel in their hands, and those back and forth misses even at 600-700yds go away, follow-ups are much faster, they don't need me to tell them where the shot went because they just watched it impact, no fatigue, etc.