Rifle purpose would be long distance target and feral hog (hence my interest).  

It seems that the 6.5 Grendel has better terminal ballistics than various 6.8 offerings.  

Several questions.  
1.  Is that correct?
2.  Which round is more common?   I will be shoot bulk out of it just for fun.  Which one is more standardized?
3.  Which one is more tolerant of a short barrel (I may make 2 uppers but not going to have 2 calibers).  
4.  I'd like to suppress it as well.  Just to make it more pleasant to shoot.  I usually shoot suppressed so I'm very realistic on suppression of a super sonic round.  I'm not going for ultimate suppression.  

I'm looking at the 6.5 Grendel.  

Sounds like you made the right choice to me.  The 6.5 Grendel has been used with suppressors in short barrels and has proven to be a good hunting cartridge even out of SBR's.  The high sectional density combined with high ballistic coefficient make it a great round for the AR-15.  Wolf has the 100 grain FMJ steel cased ammo for blasting so I'd get a chromed lined or melonite/QPQ barrel if you plan on shooting bi metal bullets.  

Privi Parizan just released a 110 grain FMJ in brass cases along with their 120 grain BTHP ammo.  Wolf sells the same 120 grain bullet as the MPT which is basically re-packaged PPU.   Hornady sells factory 123 grain Match ammo and 123 grain SST hunting ammo for the 6.5 Grendel.  Alexander Arms and Precision Firearms sell 6.5 Grendel with several different projectiles.   Most local gun shops in my area have started carrying 6.5 ammo but it doesn't stay on the shelf long.  There are many sources online for 6.5 Grendel ammo and components if you reload.

I appreciate the help.  Wow.   I didnt realize there was a sub forum for 6.5 or 6.8.   I hate to ask but is it under?   And the group buy is under the same heading?

I'll look there, but as an SBR what is the "sweet" spot for the 6.5 Grendel?   Th reason I'm considering an SBR is because of the added length the suppressor will take up.  

< No postings to 'Group Buys' unless authorized by ARFcom Staff - F >

< No postings to 'Group Buys' unless authorized by ARFcom Staff - F >

1) No, it is not. Better terminal ballistics was why Chris Murray selected the 6.8 projectile over the 6.5 for the spc.

2) You can get either, but I was at Cabelas last weekend, they had 1 load for the 6.5, and 6 from 5 different companies for the 6.8. 2 pages vs 7 pages

3) that's going to be argued forever.

4) OK.

The advantage of 6.5 is the BC of the 123gr round, but that limits your choices. Once you step away from that the BC advantage is gone.
The advantage of the 6.8 is you can gain a couple hundred FPS.

Target shooting beyond 400yds, the 6.5 has the advantage. For hunting, the bullet choice of the 6.8 has the advantage.

Sorry I didn't realize there was a rule on group buys, I'll abide by ARF.COM rule in the future.


.

I agree with this with a couple changes.

2. The 6.8 is over twice as available as the 6.5G in both ammo and parts.
It is the only one of the 2 in current militay and LEO use.

3. The 6.8 was designed for the M4 style 16in barrel, it gains or looses only 25fps per inch of barrel length.
The 6.5G gains from barrels to 24in, the 6.8 to 20in before diminishing returns.
You will never find a 7.5in 6.5G barrel, you will in 6.8.

Fact: If you hand load the 6.8 will give you much in return.

Guys on the 6.8 forum are competing out to 800 yards regularly in target shooting.
With one guy shooting 150gr Federal soft nose hand loads that meets the power factor to compete with the .308, try that with a 6.5.
The 6.5G is a fine cartridge, however the 6.8 is much more versatile and available.

1. Actually, Murray et al rigged the terminal ballistics tests with varmint projectiles, and were laughed out of the DOJ branch that analyzes terminal ballistics when considering a cartridge or projectile for LE use.  When comparing the different bore diameters for the project, SMK's were used on the other pills, while a 110gr VMAX polymer-tipped varmint projo was used in the .277 bore.  They missed a great opportunity here by choosing one of the worst bore diameters possible for the COL limitations of the case and action, namely a 43mm cut length on 30 Remington, and .277 bore.  Of course the ballistics gel results favored the varmint pill, which would have happened with any of them, but this is never told, and is overlooked or not known by people making these claims.





There is zero scientific basis to make the claim that .277 bore from an intermediate cartridge case has even noticeable terminal ballistics advantages to 6mm, 6.5mm, or 7mm. I like .277 bore in cartridges that can take advantage of .277 projectiles going over 3000fps like the .270 Winchester, but it doesn't fit well into the AR15 with a 43mm case, and limits ogive length substantially.  You can clearly see that in the picture below.  It would have been much better if they had chosen 6mm over .277"/6.8mm, or 6.35mm/.257".  A lot of us were scratching our heads when we saw what bore diameter they had chosen, especially since this was meant to be the ERC, or Enhanced Rifle Cartridge, not a CQB cartridge as many have mistakenly claimed.  The ERC was meant to provide SF with a longer-range system in the accurized AR15 Special Purpose Rifle, for basically Designated Marksmen and Snipers on ODA's.  Other units within SOCOM became interested, and asked for Remington to see if they could push the speeds 300fps faster, since they were not impressed with the external ballistics of the 115gr FMJ going 2500fps.  This led to a lot of blown up guns, and SOCOM quickly let the 6.8 go away in favor of the Mk.262 77gr OTM 5.56 NATO cartridge for the SPR instead.



Legacy 6.5mm cartridges like the 6.5x54 M-S and 6.5x55 Mauser have been used for over a century an all types of game, with an excellent track record of success.  The 6.5x54 M-S is about the ballistic equivalent of the 6.5 Grendel, since Victorian-era steels used in rifle actions had lower yield strength, and as a result, operating pressures for rifle cartridges were substantially lower then.  WDM Bell used the 6.5x54 M-S to hunt everything in Africa with, including elephant, making brain shots repeatedly.  The Steyr 6.5x54 M-S was his favorite rifle and cartridge, since it had such excellent penetration, and almost no felt recoil.

The idea that the limited projectile selection of the 6.8 is superior to 6.5mm, even in the Grendel, is simply incompatible with the reality of the vast array of 6.5mm projectiles, and proven 6.5mm terminal performance covering 119 years at moderate-to-slow speeds from these legacy cartridges, as well as the 6.5 Grendel since 2004.  Once the bullet leaves the muzzle, it doesn't care where it came from.



The streamlined, long-nosed 6.5mm projectiles not only provide higher BC's, but also offer more nose for expansion, and more tail end for penetration.  Factory ammunition are producing the same speeds from the same barrel lengths when comparing the two, so you have the option of starting with the same speed, but much higher BC with the 6.5mm, which results in more retained energy on target, with less wind drift, higher hit probability of the vitals, and greater chance of a through-and-through wound profile.

6.8 has more availability of different types of ammo after vendors were told for years at SHOT that this was Special Forces' new caliber, while 6.5 Grendel has much lower price points for practice ammo from Wolf, in addition to the mid-level, higher quality, and premium ammo.  If you're buying factory ammo off the shelves at local gun stores, you're going to get raped price-wise with either caliber. There were 34 factory loads for 6.5 Grendel last I checked.  Most people find one factory load that will do everything they need it to, like the 123gr SST, 123gr AMAX, 120gr MPT, or steel cased FMJ's.

It's better to order online no matter what cartridge you shoot.

But for a dual-purpose hunting/target cartridge in the AR15, the 6.5 Grendel has no peer when looking at factory chamberings.  You can get complete 6.5 Grendel rifles or carbines right now for $550 and up.

The Grendel has no peers when it comes to breaking bolts and over stressing the limits of the AR15 bolt system.
It has never been used and will never be used in military applications due to this weakness.

If the OP wants a 6.5G then by all means go ahead.
However know the truth about the cartridge not the inflated drivel spewed forth by some.
Ignore all this about 6.5 caliber rifles other than the 6.5G, it cannot push the projectiles to the speeds of any other 6.5.
Ironically LR's very argument against the .277 in the 6.8.
As well he didnt come to this thread until I did, as per usual.

The 6.8 has twice the market share for a reason, is more adaptable and a better all around cartridge.

*a 95gr VMAX polymer-tipped varmint projo was used in the .277 bore.  

So apparently you think they used something that doesn't exist.

*Other units within SOCOM became interested, and asked for Remington to see if they could push the speeds 300fps faster, since they were not impressed with the external ballistics of the 115gr FMJ going 2500fps.  This led to a lot of blown up guns,

The overpressure problems were because Remington screwed up the chamber with an extremely short throat and the wrong cone angle and rifling. Use the correct chamber and rifling and the extra velocity is no problem. It didn't help that they also chose the worst possible bullet weight. for the caliber.

* WDM Bell used the 6.5x54 M-S to hunt everything in Africa with, including elephant, making brain shots repeatedly.

So you really think the grendel can push a 159gr bullet to 2500 fps with an 18" barrel? Good luck with that. My 260 Remington can, but even that works better with 140-144gr bullets.

http://i1085.photobucket.com/albums/j422/LRRPF52/29133fab-659c-49c8-b522-5aef4d7bd71d_zpsa9e3d31a.jpg

Wrong title on that pic, it should read "Less than half of these can be loaded in the grendel" they are simply too long, take up too much space, and you sacrifice too much velocity for any hunting bullet to work at anything 130gr and heavier.

*There were 34 factory loads for 6.5 Grendel last I checked.  Most people find one factory load that will do everything they need it to,

That's because they can only find one load.

*You can get complete 6.5 Grendel rifles or carbines right now for $550 and up.

You can do that with several AR calibers. In other news, they have determined that water is wet.

Have a nice day and enjoy your grendel, but don't make it out to be something it isn't.

The 6.5mm fans think they have this magic bullet that defies all physics.

Fact is the 7mm bore has some of the higher BCs across the board. That's why I went with a 7mm08 for my AR10 build, and why I'm going with a 7mm Rem Mag for my long range bolt gun build.

The 6.8 SPC was never intended to be a long range gun. Although if someone made a 110 or so grain bullet as long as the 120 SST it would get the BCs up to some respectable numbers. What the 6.8 has going for it is hunting bullets that perform at it's lower velocities than the .270 Win.

A 6.5mm version based on the 6.8 SPC case still beats the 6.5 grendel, because it allows for higher pressures without stressing the bolts.

110gr VMAX, either way, it was a varmint pill, which you can still see in the pic I referenced from Doc GKR's own collection.  The terminal ballistics tests were rigged in favor of the .277 bore for some reason.  Maybe somebody really like 270, who knows, but to compare SMK's in the other calibers against the VMAX in .277 was blatantly unscientific, and they were called out on it.

Blowing up guns was not a result of the bad SAAMI chamber alone, duplex powders were.  There's a lot about 6.8 that has never seen the light of day on the internet.  It became a joke among certain military, industry, and DOJ circles because of the way it was handled across the board.

Show me load data for 6.5x54 Mannlicher-S pushing even a 140gr bullet at 2500fps, because it isn't happening, not with an 18.5" barrel carbine especially, which he used.  Max loads for 129gr and 140gr in 6.5x54 M-S are at 2400fps.  160gr are 2200fps.  Even load data for the 6.5x55 Mauser shows 160gr maxing out at 2300fps from a 29.5" barrel, when looking at that era of steel.

All of the projectiles listed can be loaded and fired from the 6.5 Grendel, to include 160gr, and it has been done.  There are several 129gr and 130gr factory loads, to include the 129gr SST, 129gr Nosler ABLR, and 130gr Swift Scirocco.

129gr ABLR easily reaches over 2400fps with CFE from an 18" barrel, has a .552 G1 BC, and expands down to 1300fps, so it offers a lot in terms of retained energy on target, penetration, and expansion.  There isn't a factory ammo option for the AR15 that comes anywhere near the performance of that load, and even makes SBR's very formidable hunting rigs.

I haven't made the Grendel out to be something it isn't.  I am very well aware of the capabilities and limitations of the 6.5 Grendel, and it is on par with the 6.5x54 M-S, within 50fps at least.

6.5mm is the sweet spot for low recoil and high BC.  Once you go to 7mm, you step slightly over that line in the recoil department, but it's a great bore with many high BC pills, but you need more projo weight to get the same BC's as 6.5mm which requires more case capacity to reach speed.

The ERC was very much meant to provide extended range on-target energy for the SPR.  The 6.8 was a half-baked submission for the ERC, and failed miserably due to poor BC's and low mv.  People don't know the actual history behind the scenes, and simply repeat what they were told by people on the civilian side that don't have the first clue what was going on with the concept and solicitation for these tools.

The 6.5x6.8 does not beat the Grendel. I've seen the numbers, and they aren't good.  Just to reach my mild loads from a 16" with CFE, guys are using 2grs more powder.  On 6.8forums, Harrison Beane clearly stated after a string of broken bolts that you should replace the Super Bolt after 6,000rds.  The margins of pressure between Grendel and 6.8 are so close, that the 6.8 does not enjoy a significant enough bolt thrust increase to have any performance advantage.

You would need to put a 30 degree shoulder on it to be competitive with the Grendel.  On top of that, you still cut out the wide range of ogive profiles when using a longer case, compared with the Grendel's 1.520" long case.  These are just basic math problems with the case dimensions.  Unless you go with a shorter case, you lose the options that Grendel gives you.  I get over 2400fps with that 129gr ABLR (.552 G1 Litz BC) on the right from a 17.6" barrel. It expands down to 1300fps.  Run the numbers on that and see what it does.  It is very impressive, especially considering how little recoil there is.

Well I am no balistcian but in one of my 6.8's (16") 95 gr. Barnes TTSX's over LT-32 killed a whitetail at 301 ranged yards.  The deer actually wobbled about 15' before dropping.  



As far as all the 6.5 bullet choices one can get mentally constipated which one to use.  Yes their are more, but is more always better?



I use the above mentioned bullet in ALL of my 6.8's from 12.5" through 18" and have found that  K.I.S.S. applies to me; Keep It Simple Stupid.  The accuracy is almost identical in all plus I don't have a large inventory of different bullets sitting idle.

I CALLS BS!! ROGER OUT!



 

Agreed.  I personally like the 123gr A-MAX.  It's killed everything it's pointed at, and works well as a target bullet that it was meant for.

I tinker around with as many projectiles as possible for the benefit of others mostly, since I started the reloading handbook projects a few years ago.

There are several hunters who have just settled on the 120gr TSX or 100gr TTSX for the Grendel for the same reasons as you.  They are great DRT medicine for hogs, let alone deer.

Both of these cartridge have proven to be great alternatives for game hunting when looking at what was common just a few years ago with the traditional bolt rifles, especially with the growing popularity of the AR15.  I like being able to reach out to ELR with a little 16" or 18" carbine that allows me to spot my own hits, even at short range, without using a muzzle brake.

I've been shooting 6.5 Grendel in various AR configs for nearly a decade, and I've never broken a bolt. I've popped thousands of rounds of 6.5G through rifles ranging from 19.5" to 11.5" and... you guessed it, I've never broken a bolt. I've used 0.136" bolt face bolts from AA, Sabre Defence, and Maxim and... you guessed it, I've never broken a bolt.

What I DON'T do is chase the velocity demon by hot-rodding handloads way past SAAMI standard pressures. Guys that do that deserve whatever happens to their guns, no matter the caliber. Luckily, 6.5 Grendel's very efficient bullets don't require warp speed to be effective.

Just pick either 6.5 Grendel or 6.8SPC based on whatever is important TO YOU: local availability of ammo, ease of finding components for a build, bullet behavior at longer ranges, or a bunch of other factors. Just pick and shoot; you can't go wrong.

And by the way, "what the military uses" is a peculiarly old-fashioned way to configure your AR; the civilian market has long left "what the military uses" behind.

Another thing to consider if if you take the 6.5 Grendel cartridge and start shooting the lighter weight bullets, they can really move, even out of just a 16" barrel like I have.  I can launch 95gr Lehigh Defense bullets just under 2800fps if I push them near max loads, I tend to go more conservative around 2650fps.  I have some 85gr bullets from Pure Precision that are 2800-2900fps with out pushing them super hard.  The BC is great on both of these mentioned bullets.  If you plan on reloading either cartridge will be great fun.  

I went with the 6.5G back in the winter over the 6.8 due to a lot of the somewhat religious sounding BC claims.  I like my build, it runs great.  I don't think one caliber is vastly better than the other.  I have a feeling brass is more available and cheaper with the 6.8 for reloading.  I get excited when Lapua brass is ~$85 per 100.  Plus there's all the belly aching about chambers and throats and head spacing with the 6.5G.  I'm sure the 6.8 has similar issues with chamber specs but there aren't two different bolt face depths that I learned about.  Everyone has their pulpit to stand on about each cartridge.  I have yet been able to shoot further than 200yds so in my case I don't think I'd notice the difference between cartridges at this point.  Plus I can't hunt with semi in PA yet.

I have not had a critter stop yet and ask me which one I shot them with! I like both the 6.8 and the 6.5 Grendel. They both have performed well on hogs and deer. My experience so far has been the 6.8 spec II is a little less finicky with loads and factory chambered rounds. But the 6.5 Grendel will give you a bit more range not much or enough to really crow about In my book. I personally like the 120 gr SST load from hornady in 6.8 it penetrates much better then the 110 gr Vmax load. Both are about equal here in availability. Just choose one and try it out for yourself and don't get caught up in the arguments as to which one is best. A truly good shooter can take both cartridges and make them perform and not blame the cartridge for some perceived short fall. I do like the Grendel a bit better with light weight varmint bullets when calling coyotes over the 6.8 spec II. Both guns are 20" barreled and out to 550 yards very comparable in accuracy with the 6.8 taking a few more clicks to get it on target. I have not tried to shoot either further in distance because I don't have the distance to shoot.

You're right that 6.8 SPC brass is cheaper. MidwayUSA has Hornady 68SPC brass for 65¢ each and 65G brass for 70¢ each.

Lapua doesn't make 68SPC brass, only 65G, so, yeah, they're gonna charge what they're gonna charge.

On the plus side, steel-case 6.5 Grendel ammo at 33¢ per round is "more available and cheaper"!



There is zero confusion if you use SAAMI 6.5 Grendel.

If you venture off into wildcat variants of the 65G, then, sure, it's a jungle. But it's the same way with any wildcat, right?

Sure there is no confusion, but that doesnt mean no problems.  

I figure I should mention my grendel is a .264LBC, so not a true grendel in the eyes of the congregation.  I will say that with exception to the Pure Precision match bullets, I can load most of the projectiles in my posession out past mag length.  100gr AMAX I am limited to about 2.265 coal to stay ~5thou off the lands and I am limited to just past mag length with Nosler BTs.  Other sleek bullets can be loaded to about 2.320-2.340.  

So for the OP, you are not just limited to saami just as you can get a 556nato chamber or a 223wylde.  Its your buck spend it how you want.  I get some killer accuracy with my "bastard" grendel.

Bless you, my son, be forgiven and go in peace. <makes sign of the cross>



Thanks for the Pure Precision reference. Had never heard of them until your mention in this thread, but am looking into them and am liking what I see!

Despite what the 6.8 fanboys claim, the 6.5 doesn't break bolts.  I've yet to hear a single report from actual Grendel owners but if you listen to the 6.8 fans you would think they are going off like popcorn.  The 6.8 is a very good caliber and short to midrange it and the 6.5 are fairly close but it doesn't hold a candle to the 6.5 when you stretch it's legs.  You don't have to be a ballistician to know the 6.5 has proven it's superiority all over the world in whatever configuration it's applied to.  That doesn't diminish the 6.8, it's ridiculous to argue such a thing.  They are both great calibers within short to medium range but the 6.5G is the indisputably better long range caliber.  Big deal, they Grendel was designed from the bottom up to be a hunting and long range target caliber so it's not some kind of slam on the 6.8 if it can't compete at the same distances, it wasn't designed to but it's still a great caliber.

This discussion has been very very helpful to me.  In the fact that I have decided to go with 7.62x51 chambering.

I am not at the point in my career where I can hand load nor am I at a skill level where I can benefit from the differences between 6.5 and 6.8.

I realize that I may have been optimistic.  I'm going with a factory 7.62x51, most likely a SCAR, so even if I need to sell it I won't take a huge loss.

The 6.5 or 6.8 will be in my future.  This is why I asked.

I have both and to be honest I don't have a problem killing anything with either.  
Op I don't think you could go wrong with either decision.  Just don't buy into everything the fanbois spew.
BTW I still haven't broken the original 6.5 AA bolt since I bought the upper back in 2010.
--edit: I see that you're going with the old reliable .30 cal.  which is better than both 6.5 and 6.8 imo

Shooting beyond 400 yards? 6.5
Shooting inside 400 yards with an occasion shot beyond that, and for hunting,6.8.  

There are some hot loads for 6.8. Especially if you reload

I personally shoot the 6.8 out to 1000 yards.
Many on the 6.8 forums are shooting to even 800 yards in competition.
There are multiple bullets between .400 to .497 BC for the 6.8 now. Something there was not even 4 years ago.

Why is hand-loading a consideration at all?  There are more factory loads to choose from for 6.5 Grendel and 6.8 than most people will ever be able to sample in a normal lifetime, and all of them were specifically meant to work in the AR15.

Reason I ask is because I got out of .308/7.62x51 because of 6.5 Grendel.

Being able to use the AR15 platform, shoot all day without any recoil fatigue, spot my own hits without a muzzle break, with 85-90% of the .308's energy on-target are what convinced me to ditch .308 Win.

Every single time I shoot someone's .308 AR, I'm reminded how good my decision was for me.  I don't know if I have jump-related injuries in my neck, or what, but I just don't like pulling the trigger on .308's anymore.

SCAR-17 is going to cost you a lot of money, enough to pay for a great AR15 with a premium barrel, match trigger, and great optics with US-made mount, with room to spare for ammo and mags.

I just did a search on several sites for SCAR-17S, and they are all $2500+.

My Lilja-barreled 18" 6.5 Grendel with Vortex Optics, NF Ti Unimount with 20 MOA, Nitride BCG, JP SCS, match trigger, mags, and even a heavy duty tripod with PIG Saddle is about what you will pay for a SCAR-17S, and that's before putting in the Geissele or any optics for the SCAR.

"Factory Loads" that run $1.25 and go well up from there (if you consider shipping) when you remove PPU/Wolf and Hornady (hell with shipping tend to run $1.00+).  So I count what 5-6 factory loads people will likely pay for, then you have all the PF loads which are on the rich side.  Sure someone else is making them, but for what they are charging one can buy a Rock Chucker, dies, and be ahead of the game after almost 200rds.  Sure they're "factory".  Handloads are not for everyone though and I have far from deep pockets, I just make beer for a living and it doesn't pay for Precision Firearms "factory" loads.  I know we have all walks of life here but claiming a Grendel is cheaper to shoot than a 7.62 is a stretch.  

I don't know why I really built one other than I could.  Its fun but at 100-200 yds a 556 would have suited me just fine for paper holes.  I live in one of the cursed states (might be the only one now) that believes semi-autos for hunting will unleash armageddon.

Buy some Barnes 62 grain or 70 grain TSX bullets and keep shooting your 5.56mm rifle.

I own 7.62x39mm, 6.8SPC, 6.5 Grendel and 6mmWOA AR-15's and can say that they are no better or worse than 5.56mm.

7.62x39mm allows for the use of cheap ammo and can be reloaded with excellent results if you can find boxer primed brass. Try Sierra Pro Hunter 125 grain .311" bullets.

6.5, 6.8 and 6mmWOA brass is expensive as hell. 6.5 Lapua brass is close to $1.00 per case. 6.8 isn't far behind. I hate loosing brass when shooting these calibers. Getting a case mangled upon ejection is just as painful.

Surplus once fired 5.56mm brass can be found for under seven cents a case. Huge advantage in my view. Buying premium .223 hunting bullets from Barnes, dedicated to hunting, is by far the most economical option.

My best accuracy from 6.5 Grendel has come when using 107 grain Sierra Match Kings. Not from hunting bullets. I get almost as good from 6.8SPC when using Sierra 115 Match Kings, again, not a hunting bullet.

Virtually all of my oddball calibers in AR15 required tweaking to get them to run semi-reliably. Magazines needed to be tweaked, ejectors needed modification, gas ports had to be enlarged or buffers needed to be changed. Sometimes all of these things were needed. C-Products and ASC magazines are economy magazines. Thankfully they make magazines for these calibers, however many times they need their feed lips ground with a Dremel or bent to get them to feed reliably. Sometimes different magazine springs are in order.

Barrett and PRI make better magazines for 6.8SPC but they cost $30 to $45 each. My AR rifles in 6.5/6.8/7.62x39 calibers remain works in progress. I'm the type of person that doesn't trust something if it's given me any problems in the past. Although the bugs have been worked out through trial and error on my part, the seed of doubt has been planted and remains.

These calibers attracted me because they were different. Now they annoy me because they are different. Ideally a new AR should be built from the ground up devoted to a slightly bigger round rather than trying to convert 5.56mm to run them. Bolt strength has been compromised and the magazines and magazine well are cramped with the larger rounds.

Cheapest steel case I can find for .308 Win./7.62 NATO is $7.95/20.

Cheapest New manufactured HPBT ammo for .308 Win./7.62 NATO is $15.15/20.

Both of those are each a dollar more than the lowest steel case and brass-cased HPBT Grendel ammo.

5.56 is definitely a valid hunting cartridge for medium game within certain parameters, especially with premium bullets.

It isn't a viable cartridge for bucking the wind and retaining energy much past 200yds though, which is why I shoot Grendel so much.  I personally have not had reliability issues, even with the older CProducts mags, no radius on my ejector on my 1st Grendel, no special tweaks.

I've also watched a lot of Grendel's at different courses and shooting events, to the point that some of the positions looked like a machinegun spendex, with no malfs at all.

Any time I see malfunctions in any AR15, it is often one that was incorrectly assembled, or used defective components from questionable vendors, no matter the caliber, especially 5.56 (which are often not even chambered in 5.56, but were reamed with a mystery or worn reamer).

The 7.62 AR's are very finicky, always have been since the original ArmaLite AR10's from the 1950's. According to Jim Sullivan (one of the ArmaLite drafters who scaled the AR10 down into the AR15 with Bob Fremont in 1957), the AR15 was always more reliable than the AR10 for some reason.  The AR15 also had the .222 Remington Special aka 5.56x45 shoe-horned into it, so we don't shoot any of the cartridges that the AR15 was engineered around, namely the .222 Remington.

To me, the AR15 and 6.5 Grendel were meant for each other.

I've seen this line of thought repeated often here, but I have yet to see anything bear it out in reality.

For example, where does the 400yd measurement come from?

It certainly isn't a point at which the two cartridges cross paths in terms of speed or energy.  If you compare both SST offerings from Hornady, which is the closest projo weight and type, with the same mv from the same barrel length, they never cross paths.  Grendel starts with a 123gr with .510 BC, and the 6.8 starts with a 120gr with .400 BC, both going the same speed.

If you compare a slow 14.5" Grendel at 2350fps with that 123gr load to a 16" 6.8 at 2460fps with the 120gr SST, then they cross paths for energy at 175yds, from which point the Grendel edges out continually.

The most common 14.5" Grendel barrel averages 2420fps with 123gr, so it exceeds the 16" 6.8 Speed by 100yds, and energy at 25yds, so you can get more performance on target with a 6.5 Grendel from an SBR compared to a 16" 6.8 when it comes to hunting, or even ringing steel.  Most of the 14.5" Grendel barrels out there are chrome-lined, so they make a great pipe to shoot steel case from for cheap practice.

wondering why the 0.49¢ .308 , boxer primed, brass cased 147 gr wasn't posted to compare pricing ?  

Sounds like OP is going .308, cool will be able to buy ammo at ANY place in America that sells ammo which since he dosen't reload is a good thing

This comment alone makes everything else you say complete drivel.

Yea, why build bullets that specifically perform better in your individual weapon, regardless of caliber.
This is why all long range shooters in competition shoot only factory ammo.
Oh wait, now they dont shoot factory ammo now do they.

Talk about drivel...

Show me a 6mm Creedmoor Factory load, or 6m x47L for that matter.  That being said factory MATCH ammunition does exist for certain calibers and is used...

I was being sarcastic as hand loads tailored to a particular weapon and particular chamber will ALWAYS out perform a factory load in accuracy and usually power/speed.

Is it not grand how the 6.5 minions always follow me around seldom actually reading the post.

Rest assured, It has very little to do with you, but more to do with the BS you type...