I adopted the 6.8 around 2007 and then sold it off for lighter large frame ARs and back then there was a lack of inexpensive ammo. Back then, I was buying SSA ammo, and it wasn't cheap. I've since moved to the 6 ARC. I wish I would have never sold the 6.8. With a 12" pistol, it was probably the most convenient hunting rifle I had for stalking deer in the hills of MO. Very versatile round.
Blessings,
It is perfect for hunting whitetails and hogs, not too small, not too large.
Hog hunting in Texas with a 6.8(not me)
https://youtu.be/Kvi1C868wdk
I don't have a 6.8, but I do love non mainstream calibers. Mine are 6.5 Grendel and 357sig. I will not sell them but 99% of the time it is 5.56 and 9mm I use now, for everyday use.
I still use my 6.8s and like shooting them. If you have the ammo you need, the 6.8 ought to still be valid for the purpose you bought it for. I recently added an upper with a 16” stainless Wilson Combat barrel; for me is a keeper and still nicer to shoot larger than 5.56. Even more than some of my favorite 7.62s (e.g., Tavor) which is also a keeper.Quote:
Originally Posted by dpast32
I'd suggest keeping it. I run both 5.56 and 6.8 SPC using Robert MURG concept in the 2008 NDIA. I like 5.56 for it's cheap cost, wide availability / cross compatability, but it's terminal performance is indeed marginal. There are NO do it all bullets available to civilians. Your either stuck with 77gr OTM which has very poor barrier blind performance and is somewhat susceptible to AOA variations (not as bad as M855 or XM193) or 62gr ATK bonded (Federal) loads, most of which are not even available in the NATO spec load. Horrible BC of .224 for that load so it's performance sucks at non-CQC distances. The terminal performance of the bonded SP is also not as good on direct hits as 77gr OTM which is probably one of the most destructive 5.56 projectiles aside from 100gr OTM (but that had poor exterior ballistics as the velocity was too low).
MK318 is now defunct / completely out of production since the Marines adopted M855A1 and M855A1 is not available to civilians in any quantity (anything out there is more of a boot legged type of purchase rather than from a consistent production source) and M855A1 still sucks against glass (compared to MK318) according to a report from 2013 also by Dr. Roberts. So what does that leave? 64gr BTSP from Winchester, also not too great against barriers and so so BC, the infamously inconsistent M855 and XM193 ball ammunition which suck against glass, have AOA issues from 0-50 yards and again once velocity drops below 2500~2600 FPS...some solid copper loads in the 55gr weight from Hornady and Barnes that have poor BC's and some of which don't do to well against glass, again. Am I missing something?
Some terminal performance issues with 5.56 can be reduced by modern projectile designs, but some issues are more caliber / bullet form factor specific and case capacity specific that can only truly be resolved by a change to a larger caliber and case. So that's why I maintain my 6.8 SPC as it provides those benefits. Nearly all the bullets in 6.8 SPC perform reasonably well as do other larger calibers like .308 etc. You can loose 50% of a 110gr OTM and you still have a whole 5.56 bullet's mass coming out the other side! And regarding hunting uses, 6.5 Grendel does not buy anyone any range, take a look at this video of a 6.5 Grendel guy testing 123gr SST hand load from a 20" barrel, at 500 yards it did not expand AT ALL. Yet we know for a fact 120gr SST expands down to 1700 FPS in 6.8 SPC because of the higher drag.
Drag works against you when flying through the air, buy FOR YOU when impacting the target. Extremely low drag bullets require higher velocities to produce sufficient drag just to expand at all and even higher velocities to expand as much as larger calibers. Thus any small velocity advantages of 6.5 Grendel for hunting purposes are IRRELEVANT as both cartridges are limited to about 400 yards to get expansion, but 6.8 SPS is more destructive.
Take a look at what I get from two hand built uppers:
16" Daniels Defense 1:7 NATO barrel: 2585 FPS from IMI 77gr Razor Core (I get 2685 from 77gr Black Hills which is the hottest 77gr load I've used, but the difference by 500 yards is only 30 ft-lbs). The BC of 77gr OTM is around 0.362 G1
16" Daniels Defense 1:11 SPC II S2W barrel: 2600 FPS flat from 110gr Hornady OTM and these are SAAMI spec loads, not true SPC II spec. BC is 0.360. Nearly identical trajectory to 77gr IMI, but much more mass / energy (nearly 50% by 500 yards). I
Both are very accurate (1MOA consistently), but 110gr OTM does rather well through glass and a variety of barriers that 77gr does not. 110gr also produces a much longer wound channel in my ballistic gel and with a neck length of only 2 inches vs. 4 inches for 77gr (aka 77gr still doe not yaw in the ideal range of 3" or less). I also shot M855 from that same barrel and got around 2960 FPS, right on spec, but the neck length is terrible, nearly 6 inches before yaw! That load would ice pick and is not suited for duty (let alone it's also terrible glass performance).
And long range? Bah! What a joke. I know people will talk about exterior ballistics past 500-600 yards...yet most of those people have never even shot out that far and certainly NOT under field conditions which are far less ideal than bench rests at a range. Simply put, 6.5 Grendel is NOT a long range cartridge. You can shoot it out to 800-1000 with longer barrels and the right loads, but the terminal performance at that range is ABYSMAL, especially compared to 6.5 Creedmoor or 277 Sig Fury etc. At a 1,000 yards 6.5 Grendel bullets have the KE less than a .22 LR, wont' expand and have poor barrier blind performance due to their inherent instability (longer thinner projectiles are more unstable than shorter fatter ones)! It's a mid-range cartridge just like 5.56, 6.8 SPC, but has weaker bolts (aka same issues at 7.62x39mm AR's and why 300 BO is a superior choice in an M4, mostly due to reliability) and terminal performance that is between 5.56 and 6.8 at it's usable ranges. It was focused primarily to maximize exterior ballistics all else be damned, but can serve as a decent hunting cartridge and for home defense. Lethal, but not ideal by any means.
You simply cannot pack more fire power into an M4 than 6.8 SPC at the effective ranges one can realistically shoot. SF was primarily looking to enhance performance from 0-400 with occasional use out to 500-600 in rare circumstances. You can get frag / expansion out to 400 from 16" barrels with 6.8 SPC and at ranges past that the bullet in any of these calibers is just a FMJ, so you need precision shot placement or deal with decreased wounding, which at those ranges is ok as they aren't going to be placing precision return fire from 500 yard after getting shot in the lung with an OTM that didn't expand, especially in larger calibers, even if they survive.
I think the fact that the US Military required 6.8mm says it all. That requirement was decided BECAUSE of the testing done during development of 6.8 SPC and various other calibers and even 5.56 ammunition. What they found is that when comparing the same bullet design, 6.8mm projectiles had the ideal balance of damage vs. exterior ballistics. I'm not sure why people are so obsesses with exterior ballistics and this fantasy of long range engagements with 6.5 Grendel...it's poorly suited to being used at those ranges even if it can place hits that far.
Long distances will always be dominated by larger cartridges. Period. If your in the mountains of Afghanistan, would you rather have 6.5 Grendel that has less KE than .22 LR at 1,000 yards or 277 Sig Fury or 6.5 Creedmoor? Why not simply return to having a dedicated DMR at the Fire Team or Squad Level like most other militaries? Russia still employs SVD's in 54R to augment 5.45x39mm and 7.62x39mm assault troops vs. trying to use one caliber that compromises too much in one area or another.
1. 2008 Report on Small Arms (Roberts, 2008): https://ndiastorage.blob.core.usgovc...tl/Roberts.pdf
2. An Optimized Caliber and the IC Competition (Schatz, 2011): https://ndiastorage.blob.core.usgovc...1456Schatz.pdf
3. Do We Need a New Service Rifle Cartridge? (Schatz, 2012): https://sadefensejournal.com/do-we-n...fle-cartridge/
4. Wound Ballistic Terminal Performance Facts (Roberts, 2013): http://nebula.wsimg.com/fb54bbe7bcde...&alloworigin=1
5. Where To Now 17354 (Schatz, 2015): https://ndiastorage.blob.core.usgovc...354_Schatz.pdf
6. The Path to Overmatch 18260 (Schatz, 2016): https://ndiastorage.blob.core.usgovc...260_Schatz.pdf
7. 19394 Maintaining Overmatch (Zhou, 2017): https://ndiastorage.blob.core.usgovc.../Zhou19394.pdf
If you read through that sequence, you can see all of the testing data and also how their thinking changed over time. Ultimately they really liked what they saw in 6.8 SPC, however they decided that they wanted to add capability to defeat body armor at ranges that 5.56, 6.5 Grendel, 6.8 SPC etc. and other intermediate calibers could not (typically they were all limited to 75~100 yards for defeating level IV). That simply required a larger cartridge period. They also wanted extended ranges beyond what any of these intermediate calibers can practically deliver. So they took the 6.8mm 130~135gr bullet requirement and added some velocity, aka approx. 3000 FPS and from a 16" barrel length (carbine).
We now ended up with 277 Sig Fury and the M5 rifle, the M250 belt fed machine gun. However 277 Fury has ALL the same disadvantages as .308, just enhanced exterior ballistics with nearly the same terminal performance. Higher recoil, half the ammo capacity, large muzzle blast / flash requiring a suppressor and a much heavier AR-10 like weight (the MCX Spear aka M8 is 8.4lbs UNLOADED, NO SIGHTS, NO MAG etc.). I think the belt fed is a great, but I think the M5 is NOT going to replace all M4's in 5.56, instead I think it will more realistically augment them as a DMR role with much more enhanced performance over an SVD in 54R. It's well suited to true intermediate (300-600) and even long range engagements (600 to 1,000).
BTW take a look at this: https://www.youtube.com/watch?v=XiEx_JQCfbg
123gr SST hand load, 6.5 Grendel from a 20" barrel almost nobody uses on an AR except for hunting. Zero expansion. According to Hornady ballistics calculator, that bullet would impact at around 1800 FPS at that range, with that MV. So we know for a fact that 6.5mm low drag projectiles require more velocity just to get any expansion. Cavity Back Bullets lists the same thing, 6.5mm MKZ requires about 100 FPS more to expand than 6.8mm MKZ. So at ranges one can actually shoot and hit something in the real world, especially when taking incoming fire, there's no advantage, in fact your at a disadvantage because of barrier blind and direct hit terminal performance is inferior with 6.5mm. They literally tested 6.5mm SPC...and 6mm and 7mm and 7.62mm, all in the same case, same bullet designs.
I still scratch my head to this day why people think 6mm and 6.5mm low drag bullets are magic. They somehow have low drag while flying through the air but magically then have higher drag upon initial impact. What they fail to realize is that their low drag bullets actually require more velocity to achieve any expansion because you have to generate enough drag forces to deform the bullet, thus the slight benefits in velocity, drop and drift at 400~500 yards are meaningless because they are so small and because they don't make up for the higher velocity requirement to achieve desired terminal performance.
But at ranges past 500 yards other larger calibers deliver far better performance like 7.62x51mm, 6.5 Creedmoor, 277 Fury etc. that hold much higher velocities where they will still expand / fragment. My point is that 6.8 SPC is a very well designed cartridge that delivers approximately 80% of the terminal performance of a 7.62x51mm out to 300 yards on target with the same effective range as the existing 5.56 (accurate out to 500~600 yards) and close to the same system weight and ammo capacity as 5.56, while maintaining 5.56 like reliability in an M4 chassis. Blast and flash is also fairly comparable to 5.56 if not a bit less in my personal experiences.
There simply is not a better suited cartridge to the M4 than 6.8 SPC and why should there be? It's competitor, the 6.5 Grendel was not designed by members of the US Military, it was designed by someone focusing on exterior ballistics rather than addressing terminal performance issues from 0-400 yards. While 6.5 does offer superior terminal performance on direct hits compared to 5.56, it's not as good as 6.8 SPC and 6.5mm low drag projectiles perform rather poorly against barriers (similar to 77gr OTM's). So what are you gaining?
75% of combat in Afghanistan took place at distances und 485 yards. That's 3/4 of engagements and the remaining 25% were primarily in the mountains, not in the urban areas that typically did not exceed 500 yards. So why not take a suitable tool for the mission? Going up to the mountains...take a larger caliber, the trade offs are worth it. Fighting in the towns and city areas? Take 6.8 SPC in a light weight M4.
I think 6.8 SPC is getting some new attention due to the results of the NGSW project and their final choice of 277 Sig Fury. 6.8 SPC is like 277 Sig Fury Short or 277 Sig Fury is like a 6.8 SPC Magnum, however you look at it.
Current Ammo Suppliers for 6.8 SPC:
1. Hornady 110gr Black (VMax), 120gr SST, 100gr CX (you can buy the original 110gr OTM bullets for hand loading still)
2. Federal 115gr Fusion and 90gr Fusion
3. Barnes 95gr TTSX and 110gr TSX loaded by Wilson Combat
4. S&B 110gr PTS (this is actually one of the best all around bullets for 6.8 SPC) and 110gr FMJ for practice
5. 105gr MKZ and 120gr MKZ
6. Winchester 115gr OTM and 115gr Extreme Point
7. PPU 115gr OTM and FMJ
8. Underwood 110gr VMax
9. Remington UMC 115gr FMJ
10. Druid Hill Armor SPC II loaded 110gr VMax, 120gr SST etc.
11. Stand 1 Armory 120gr SST
12. And if your LE / Military / Private Security you can get 75gr or 97gr Tungsten AP: https://modernarmsinternational.com/...nt/6-8-spc-le/
THANKS 'win&legend' very much for your quite informative & detailed reply, it was much appreciated. I tended to be a Fan of the 6.8 SPC almost immediately, as soon as I became aware if its overall capabilities & 'middle of the road' effectiveness. I was willing to accept the 5 rd capacity loss, if it meant gaining the advantage of an 110+/- grain projectile at around 2,600 FPS, as opposed to the basic 5.56 NATO of 62 grain M-855 at around 2,600 FPS from a 14.5". IMHO, there's much to be gained as a mid-range cartridge, without a whole lot not to like, at least as far as I'm concerned. Some people tend to champion the 6.5 Grendel over the 6.8, & if you're comparing some long range usage, well it does lag slightly behind. I feel the SPC is entirely suitable for out to 650 meters, & will handle anything below that quite nicely. Personally, I'm glad I need keep mine, as it allows me to utilize yet another useful caliber for both hunting, & short to medium+ range defensive purposes. THANKS AGAIN for your input, it was truly appreciated.
Best regards, Dom P. / 'dpast32'
Well, just responding to the title…. Mike Pannone just burned through his remaining 6.8SPC and is rebarreling that upper to a different caliber. So there’s one person who thinks it is done.
https://www.instagram.com/p/Cg99W6bJMWH/?igshid=NmNmNjAwNzg=
Win&Legend,
thanks for putting the time into all that, but:
You say that Grendel expansion sucks out at 500yds, but SPC Hornady factory SST will expand down to 1700fps. While I believe both of those things may be true, you may want to run the numbers on that. That load gets you 375yds of expansion with the 1700fps floor, so it would produce the same shitty results at 500.
There was exactly as much need for discussion of .mil interest in 6.8 SPC as there is for .mil interest in .260Rem. And comparison with 6.8Fury belongs as much as the dude that brings up 300PRC in a discussion of 30-30. They are not alike in any way but bore diameter.
Dom,
Minor thing, but you mention M855 being 2600 from a 14.5” gun. Thats not quite right; that’s a Mk18 velocity. From a 14.5”, M855 can be expected to be in the 2900s. The main point you were making about energy is still true, of course.
Well Guys, Please be advised that after my thinking about it, that unless I had someone ready to offer me an exceptional sum for my 6.8, I have decided to keep it indefinitely. As we all know, it definitely performs over & above the 5.56 for pretty much all purposes, both 'serious' work, & hunting. I'm honestly not certain as to it can claim to be more accurate than the 5.56 but for my intended purposes, it really doesn't matter, as my longest shot would under 600 +/- meters, for which the 6.8, provided it's fed the proper ammunition should perform nicely. When initially purchased, I obtained whatever I thought would be required, so picked up an ample supply of 25 rd PRI 'Waffle' Magazines, along with the C Products 25 rd one that came with it. As far as available ammunition, well, unfortunately I never stocked up, as up until recently only the premium brands were available. ( At least I did pick up some 600 rds, broken down into 240 rds of 110 gr. Hornandy L.E. TAP, 240 rds of 110 gr. Hornandy L.E. TAP 'Urban', & 120 rds of Remington 115 gr. BTHP ) So theoretically at least, I should have enough to get my Stag Model 5 nice & hot anyway. And, in addition to possessing an additional Caliber, I have yet another reason for my Stag M-5. I also utilize the Receiver for my recently obtained BCM 5.56 Complete Upper, which I ordered with an 14.5" P & W Barrel. That way I can use the BCM for whatever, & keep my Colts from getting worn or dinged up. ( Colt R-6520 & 6920 ) I & probably many others here may have felt that the 6.8 SPC was definitely 'going somewhere' when it was introduced. Yet, once the U.S. decided it wouldn't be 'cost effective' to convert all the existing M-16 / M-4's to it, it all but fell by the wayside so to speak. As far as I know, the only subsequent U.S. Government usage was some occasional use by USSF Personnel, & a few Foreign entities, primarily in the Middle East arena. It remains too darn bad for everyone, as the 6.8 SPC did indeed have something to offer the average user, whether they be Military, Law Enforcement, & or Civilian, it offered something for everyone, at least IMHO. So, 'hopefully' as ammunition supplies make their way onto store shelves & Internet Order Depots, just maybe we'll start seeing some S&B FMJ, Fiocchi, PPU, & or any of the other lower cost ammo to feed our 6.8's, thereby saving the 'good stuff' for more important uses.
Best, Dom P.