Yeah, I just tire of arguing with the Grendel people.
Sent from my Pixel 3 using Tapatalk
The 6.8x51
21 - 40 of 60 Posts
Sent from my Pixel 3 using Tapatalk
Joined
·
451 Posts
Got any data on it? I posted the info I found on the 6.8 AP loads that existed, but they were limited to penetrating Level IV to 100 yards. I've never seen anything out to 200 yards for 6.8 since it wasn't ever put into service, I only know of two loads developed for it. 97gr and 75gr AP. See attachments.
Attachments
Joined
·
451 Posts
BTW, I still maintain 6.8x43mm is a vastly superior solution to all things 5.56 NATO and eventually I'd like to get a M5 (MCX Spear) for longer range applications as that's it's bread and butter. Sometimes you just need more fire power and there's no replacement for displacement.
Well, no matter what the military does, I still love my 6.8 SPC. To me it is a jack of all trades for Texas hunting. I guess that I will just start collecting more brass so that I can still shoot my little toy gun when the ammo manufacturers stop making factory pills for it. BTW, all you guys realize that this conversation is academic. We will all have to wait until the rifle and accessories are actually in the field for a few years to evaluate who is right and who is just waxing flatulantly... Peace out brothers and sisters....
Joined
·
654 Posts
Agreed. However I posted this short clip excerpt on another thread and I agree with the idea that it would have been better if the cartridge that the new 6.8x51 80,000 PSI hybrid was based on the 6.8 SPC instead:Well, no matter what the military does, I still love my 6.8 SPC. To me it is a jack of all trades for Texas hunting. I guess that I will just start collecting more brass so that I can still shoot my little toy gun when the ammo manufacturers stop making factory pills for it. BTW, all you guys realize that this conversation is academic. We will all have to wait until the rifle and accessories are actually in the field for a few years to evaluate who is right and who is just waxing flatulantly... Peace out brothers and sisters....
✂️ Why not a 80,000 PSI 6.8 SPC steel base hybrid instead?
24 seconds · Clipped by Jerry Winkler · Original video "Goody bye M16! Military Adopts the M5 rifle and 6.8x51. Are they crazy?" by Military Arms Channel
youtube.com
Joined
·
1,071 Posts
If Sig had to push 6.8x51 to 80,000 psi to get the velocities that military required, I can't imagine they could have accomplished the same with the 6.8x43. Anyone have that loading program to see what it says? I think a 6.8 SPCIII / mini-fury would be awesome. Anyone have an "in" at Sig?
Joined
·
451 Posts
An 80,000 PSI hybridized 6.8 SPC would have necessitated a new rifle chassis because the bolt design of AR-15's or even AR-10's cannot facilitate those working pressures, I doubt the chambers could have handled it even if the bolts could have. And the Army specified pushing a 130-135gr 6.8mm projectile of their design (as I posted above, a scaled up M855A1 bullet) to 3,000 FPS from a 16" barrel.
A hybrid 6.8 SPC wouldn't be able to meet those requirements, although I do think you could get it to push a 110gr bullet to those velocities. Either way, an entirely new chassis, barrel and bolt would have been needed anyway. But consider a scaled up M855A1 bullet as a 110gr .360 BC 6.8mm bullet in a hybridized 6.8x43mm case, pushing 3,000 FPS from 16". That would have been a true "intermediate" round. I know H has gotten 2700 to 2750 consistently for 110gr OTM's from 16", so I don't think 3,000 is unrealistic for a hybrid case and rifle chassis capable of 80k psi chamber pressures.
However, I do agree that a 6.8x43mm "Fury" or 277 Fury Short, what ever you might call it, would have increased ammunition capacity over 6.8x51mm and reduced over all weight compared to 6.8x51mm considerably while being a true "middle of the road" cartridge. Even in it's form now, 6.8x43mm significantly out performs 5.56 at all things 5.56ish.
Pushing 3000 FPS from a 110gr 6.8mm load from a 16" barrel would have been a real darling in something that is within 1lb of the weight of AR-15's in 5.56. That's a lot of fire power in a very light weight, compact package. The MCX Spear is anything but compact and lightweight with a suppressor even with it's 13in barrel, it's still a full sized battle rifle that's slightly bulkier than an AR-10 (which when done right, isn't bad as that's the trade off). And if you try to use it without a suppressor....good night, the blast, concussion and recoil is MASSIVE. It's really designed to be used suppressed.
But I get the logistics and reasoning of it. 5.56x45mm is heavily entrenched with NATO allies and the US military both in terms of production, equipment and available ammunition stores. All branches of the US military have now standardized on M855A1 as a general purpose combat load with enhanced LAP capability, the early frag with the solid copper core slug that typically penetrates about 20 inches addresses some of the most critical short comings of 5.56x45mm. Most civilian LE agencies now use 62gr bonded (Federal) either in .223 spec or NATO spec pressures as they don't need ranges beyond 100 yards, but the BC is terrible at .224....
Sure, a 6.8x42mm A1 load, if it were developed, would outperform M855A1 in 5.56 just like M80A1 in 7.62x51 significantly outperforms M855A1, but I believe they found the M855A1 to generally meet their requirements and reasonably address the short comings of 5.56 for it's given role. It really is a short to at most medium range cartridge.
1. M855A1 addresses AOA dependency from 0 to 50 meters. Because it is not angle of attack dependent, it doesn't ice pick randomly at CQB distances like M855 did.
2. It has the same ballistic coefficient (0.306) as M855, so any combat sights and training centered around M855 exterior ballistics are close (in practice it's not exact as any experienced hunter would expect).
3. As far as I know, it's performance through intermediate barriers such as auto glass is significantly better than M855 or MK262. That's because the base is a solid copper slug where the other two loads were lead core, the whole bullet would break apart. I would expect performance through auto glass to be similar to ATK 62gr Bonded SP.
4. NWCS-Crane found that during testing of gas port locations on carbines that with the Geissele URG-I's (which originally had barrels made by Daniels Defense), that cold hammer forged chrome lined mid-length barrels lasted 2x that of typical cut rifled GI-spec chrome lined barrels.
Note: I suspect that the increased service life is more to do with the gas port location AND more importantly, the modern electro-plating processes used for chrome lining than the hammer forging of the barrel because of the studies Boeing did on air craft guns (see attached images). They are NOT the same. Typical GI spec chrome lining is vastly inferior to some of the more modern processes that avoid mico-cracks that are the source of early failure in chrome lined bores.
5. M855A1 provides a longer fragmentation range, I've seen some gel shots of M855A1 shot out of a 10.3" barrel at 2400 FPS and still fragment quite well. I suspect it will fragment down to between 2000 FPS or possibly less which extends the ideal terminal performance threshold out to around 350 yards from a 16" barrel. That's pretty good for 5.56 and matches the effective terminal range of most 6.8 SPC hunting loads.
So I think that covers some of the biggest reasons why they stayed with 5.56 for now with 6.8x51mm to fill in where more fire power is needed. None of this invalidates the merits of 6.8x43mm which simply out performs 5.56 at all ranges one would use 5.56.
And as a civilian, you cannot get and will likely not be able to get M855A1 for your 5.56 rifle any time soon as they are not making surplus available to the American public at the present time. That leaves you with 77gr OTM's, 62 and 64gr bonded SP's which have horrible BC's (only good for close range, but do well against barriers) and the erratic M855 along with some exotic solid coppers which don't have great BC's either (again, mostly close range use) and also cost nearly $2 a round. MK318 is now defunct, out of production entirely in 5.56. So what's left to civilians or LE? Specialized loads only good at one thing. There's nothing that would work well for a general purpose load in 5.56 that doesn't really give up in one area or another.
Attached is some load testing data for M855A1 you might find interesting. Even with the pinnacle of 5.56 ammunition, I'll point out that a 24gr slug that remains after it looses 60% of it's mass on impact is simply not going to do as much damage deep within the target as a 60-70gr slug from a 6.8 SPC bullet that lost 50% of it's mass. Sometimes, there simply no replacement for displacement or getting around the fact that half of a 6.8 SPC bullet will always be...a whole 5.56 bullet!
A hybrid 6.8 SPC wouldn't be able to meet those requirements, although I do think you could get it to push a 110gr bullet to those velocities. Either way, an entirely new chassis, barrel and bolt would have been needed anyway. But consider a scaled up M855A1 bullet as a 110gr .360 BC 6.8mm bullet in a hybridized 6.8x43mm case, pushing 3,000 FPS from 16". That would have been a true "intermediate" round. I know H has gotten 2700 to 2750 consistently for 110gr OTM's from 16", so I don't think 3,000 is unrealistic for a hybrid case and rifle chassis capable of 80k psi chamber pressures.
However, I do agree that a 6.8x43mm "Fury" or 277 Fury Short, what ever you might call it, would have increased ammunition capacity over 6.8x51mm and reduced over all weight compared to 6.8x51mm considerably while being a true "middle of the road" cartridge. Even in it's form now, 6.8x43mm significantly out performs 5.56 at all things 5.56ish.
Pushing 3000 FPS from a 110gr 6.8mm load from a 16" barrel would have been a real darling in something that is within 1lb of the weight of AR-15's in 5.56. That's a lot of fire power in a very light weight, compact package. The MCX Spear is anything but compact and lightweight with a suppressor even with it's 13in barrel, it's still a full sized battle rifle that's slightly bulkier than an AR-10 (which when done right, isn't bad as that's the trade off). And if you try to use it without a suppressor....good night, the blast, concussion and recoil is MASSIVE. It's really designed to be used suppressed.
But I get the logistics and reasoning of it. 5.56x45mm is heavily entrenched with NATO allies and the US military both in terms of production, equipment and available ammunition stores. All branches of the US military have now standardized on M855A1 as a general purpose combat load with enhanced LAP capability, the early frag with the solid copper core slug that typically penetrates about 20 inches addresses some of the most critical short comings of 5.56x45mm. Most civilian LE agencies now use 62gr bonded (Federal) either in .223 spec or NATO spec pressures as they don't need ranges beyond 100 yards, but the BC is terrible at .224....
Sure, a 6.8x42mm A1 load, if it were developed, would outperform M855A1 in 5.56 just like M80A1 in 7.62x51 significantly outperforms M855A1, but I believe they found the M855A1 to generally meet their requirements and reasonably address the short comings of 5.56 for it's given role. It really is a short to at most medium range cartridge.
1. M855A1 addresses AOA dependency from 0 to 50 meters. Because it is not angle of attack dependent, it doesn't ice pick randomly at CQB distances like M855 did.
2. It has the same ballistic coefficient (0.306) as M855, so any combat sights and training centered around M855 exterior ballistics are close (in practice it's not exact as any experienced hunter would expect).
3. As far as I know, it's performance through intermediate barriers such as auto glass is significantly better than M855 or MK262. That's because the base is a solid copper slug where the other two loads were lead core, the whole bullet would break apart. I would expect performance through auto glass to be similar to ATK 62gr Bonded SP.
4. NWCS-Crane found that during testing of gas port locations on carbines that with the Geissele URG-I's (which originally had barrels made by Daniels Defense), that cold hammer forged chrome lined mid-length barrels lasted 2x that of typical cut rifled GI-spec chrome lined barrels.
Note: I suspect that the increased service life is more to do with the gas port location AND more importantly, the modern electro-plating processes used for chrome lining than the hammer forging of the barrel because of the studies Boeing did on air craft guns (see attached images). They are NOT the same. Typical GI spec chrome lining is vastly inferior to some of the more modern processes that avoid mico-cracks that are the source of early failure in chrome lined bores.
5. M855A1 provides a longer fragmentation range, I've seen some gel shots of M855A1 shot out of a 10.3" barrel at 2400 FPS and still fragment quite well. I suspect it will fragment down to between 2000 FPS or possibly less which extends the ideal terminal performance threshold out to around 350 yards from a 16" barrel. That's pretty good for 5.56 and matches the effective terminal range of most 6.8 SPC hunting loads.
So I think that covers some of the biggest reasons why they stayed with 5.56 for now with 6.8x51mm to fill in where more fire power is needed. None of this invalidates the merits of 6.8x43mm which simply out performs 5.56 at all ranges one would use 5.56.
And as a civilian, you cannot get and will likely not be able to get M855A1 for your 5.56 rifle any time soon as they are not making surplus available to the American public at the present time. That leaves you with 77gr OTM's, 62 and 64gr bonded SP's which have horrible BC's (only good for close range, but do well against barriers) and the erratic M855 along with some exotic solid coppers which don't have great BC's either (again, mostly close range use) and also cost nearly $2 a round. MK318 is now defunct, out of production entirely in 5.56. So what's left to civilians or LE? Specialized loads only good at one thing. There's nothing that would work well for a general purpose load in 5.56 that doesn't really give up in one area or another.
Attached is some load testing data for M855A1 you might find interesting. Even with the pinnacle of 5.56 ammunition, I'll point out that a 24gr slug that remains after it looses 60% of it's mass on impact is simply not going to do as much damage deep within the target as a 60-70gr slug from a 6.8 SPC bullet that lost 50% of it's mass. Sometimes, there simply no replacement for displacement or getting around the fact that half of a 6.8 SPC bullet will always be...a whole 5.56 bullet!
Attachments
Joined
·
8 Posts
Can someone tell me if the new Sig rifles will be compatible with the 6.8 SPC, if not why? I am just not very well versed in ballistics ;-) but I do own a 6.8 SPC AR platform and a bunch of 6.8 SPC ammo. I know the .277 Furry requires a heavier barrel but I did not know if it was compatible with the 6.8 Common Cartridge or the 6.8 SPC.
Joined
·
18,690 Posts
No, the sig Fury is the size of a 308
Joined
·
740 Posts
I don't argue with the 6.5 guys, just wait for their bolt to break and keep making hits with my 6.8 they were missing with their 6.5 and whey they got frustrated slinging rounds till they break their gun. Most things being equal a 6.8 bolt will outlast two or three 6.5 bolts. Dope it right or not doesn't matter the cartridge. I have a few more inches drop at range, big deal, the shots still hook up.
Joined
·
18,690 Posts
Time will tell what happens but I don't see the poly cases as being reloadable. That ammo will be expensive but someone could make a brass case version with the same chamber so either ammo could be shot from it and those that want to reload can at a reduced pressure and velocity. It is basically a 270-08 30* AI.
If the 2 piece ss and brass cases are reloadable they may handle the full 80k psi but we wont know until some get out there in the hands of civilians.
If the 2 piece ss and brass cases are reloadable they may handle the full 80k psi but we wont know until some get out there in the hands of civilians.
Joined
·
740 Posts
My 200 yard statement was wrong (sometimes I do that) but remember the MAI ammo is loaded to 6,8 SPC pressures same as XM68GDs because that is what Uncle Sugar tested and their bigger clients (middle east) adopted early. That bullet in both the 75 gain and 97 grain loaded to upper end of 6.8 spc II range will punch a USGI "30-06 AP" rated plate at a greater distance than 100 yards. Beyond this can't say too much. I now have NIJ 4 plates under three pounds now and a set under four pounds. Even have a front plate at 2.9 pounds in female shape for the wife.
While military use around the world is really ramping up their armor and night vision to keep up it comes with a weight price when up armoring, most of my military armor is rated "burst from 9mm submachine gun" for soft, "7.62x51 M80 ball", "30-06 AP" and other similar nomenclature. They are not using NIJ standards in marking their plates and the 30-06 AP plates I have are miserable weight to wear, especially in the large size so I shot one of my sets to discover it doesn't like certain loads that I would want to stop in combat.
No military issue plate I have been able to acquire and shoot will stop 7.62x51 ADVAP. ADVAP is nothing more than M80a1 EPR with a tungsten penetrator instead of mild steel used in M80a1. Have some of the new kits from Australia and Romania (Romy is good stuff and issued in female) and some that carries "DARPA" labels. The lightweight plates seem to only be filtering into Tier 1 units best I can tell but as normal what the Tier 1 units are using today will filter to the regular GIs with time.
Issue is it will take just a little training to teach them to go for hip shots where a busted artery will bleed out almost as fast as a heart or liver shot. Same with neck and face, NIJ 3 helmets are already out and have two not counting the SLAAP Plates that Velcro to standard MICH helmets that up-armor them to NIJ 3 but kit even a burly man out with a Level 3 helmet, milspec Level 4 threat plates, fully kit him out with comms, IFAK, the new rifle ammo load out, etc and they will have 100 pounds of gear.
I would have swapped M4s over to the 6.8 while adopting the spc II standard instead of SPC and then replaced the M110 Sass with the new SIG rifle. Each squad sized group would have their SDM/SPR toppers with the bigger rifles while allowing the bulk to still be light and fast. Am currently working on a project to shoehorn 280 AI in a BN-36 or LAAR chassis which the receiver and magazine is a tad longer than AR 10s but will handle 30-06, 25-06, 280 AI and possibly 7mm Rem Mag at competitive weight with the new rifle and be less expensive plus sharing enough parts would be less for armorers to inventory.
I believe the military is thinking way beyond he NIJ 4 plate. Have some military issue only Tencate plates along with lightweight flexible NIJ 3 (Stealth Armor Systems Hexar) and swapping groin, shoulder along with flexible lightweight side armor to Level 3 is here. But like with ACOGs increasing the hit probability of average 11 Bravo in Gulf 2 and Afghanistan, the new optic the Army is about to field that ranges the target, figures wind drift and puts bullet on target is going to allow way more "average" infantrymen to make "Scout Sniper" quality shots.
We learned some hard lessons in Afghanistan with the M4 which could have been solved such as all the rifle failures at the Battle of Wannat. Have already started swapping my gas tubes to V Seven Inconel Extreme Environment tubes, using advanced material bolts including those made with S7 steel instead of Carpenter 158 and swapping my cam pins out to the V Seven Improved Cam Pin. Just swapping a few parts in the M4, slowing cyclic rate down with MGI Rate Reduction Buffers combined with 4150 melonite barrels and we have not been able to cook an AR upper on full auto lowers yet.
These are 6.8 uppers running full power spc II loads and running mag dump after mag dump. Same improvements on the Sr-25 and swapping it over to 6.5 Creed could have transitioned the military to much improved equipment on a budget and kept a competitive edge for a couple more decades.
While military use around the world is really ramping up their armor and night vision to keep up it comes with a weight price when up armoring, most of my military armor is rated "burst from 9mm submachine gun" for soft, "7.62x51 M80 ball", "30-06 AP" and other similar nomenclature. They are not using NIJ standards in marking their plates and the 30-06 AP plates I have are miserable weight to wear, especially in the large size so I shot one of my sets to discover it doesn't like certain loads that I would want to stop in combat.
No military issue plate I have been able to acquire and shoot will stop 7.62x51 ADVAP. ADVAP is nothing more than M80a1 EPR with a tungsten penetrator instead of mild steel used in M80a1. Have some of the new kits from Australia and Romania (Romy is good stuff and issued in female) and some that carries "DARPA" labels. The lightweight plates seem to only be filtering into Tier 1 units best I can tell but as normal what the Tier 1 units are using today will filter to the regular GIs with time.
Issue is it will take just a little training to teach them to go for hip shots where a busted artery will bleed out almost as fast as a heart or liver shot. Same with neck and face, NIJ 3 helmets are already out and have two not counting the SLAAP Plates that Velcro to standard MICH helmets that up-armor them to NIJ 3 but kit even a burly man out with a Level 3 helmet, milspec Level 4 threat plates, fully kit him out with comms, IFAK, the new rifle ammo load out, etc and they will have 100 pounds of gear.
I would have swapped M4s over to the 6.8 while adopting the spc II standard instead of SPC and then replaced the M110 Sass with the new SIG rifle. Each squad sized group would have their SDM/SPR toppers with the bigger rifles while allowing the bulk to still be light and fast. Am currently working on a project to shoehorn 280 AI in a BN-36 or LAAR chassis which the receiver and magazine is a tad longer than AR 10s but will handle 30-06, 25-06, 280 AI and possibly 7mm Rem Mag at competitive weight with the new rifle and be less expensive plus sharing enough parts would be less for armorers to inventory.
I believe the military is thinking way beyond he NIJ 4 plate. Have some military issue only Tencate plates along with lightweight flexible NIJ 3 (Stealth Armor Systems Hexar) and swapping groin, shoulder along with flexible lightweight side armor to Level 3 is here. But like with ACOGs increasing the hit probability of average 11 Bravo in Gulf 2 and Afghanistan, the new optic the Army is about to field that ranges the target, figures wind drift and puts bullet on target is going to allow way more "average" infantrymen to make "Scout Sniper" quality shots.
We learned some hard lessons in Afghanistan with the M4 which could have been solved such as all the rifle failures at the Battle of Wannat. Have already started swapping my gas tubes to V Seven Inconel Extreme Environment tubes, using advanced material bolts including those made with S7 steel instead of Carpenter 158 and swapping my cam pins out to the V Seven Improved Cam Pin. Just swapping a few parts in the M4, slowing cyclic rate down with MGI Rate Reduction Buffers combined with 4150 melonite barrels and we have not been able to cook an AR upper on full auto lowers yet.
These are 6.8 uppers running full power spc II loads and running mag dump after mag dump. Same improvements on the Sr-25 and swapping it over to 6.5 Creed could have transitioned the military to much improved equipment on a budget and kept a competitive edge for a couple more decades.
My sense is neither dollars or pounds were major factors in the decision tree. Nor were all lessons learned to date incorporated. As usual the WAGs are still trying to fight the last war, and not very intelligently.
Joined
·
740 Posts
One more mention, how many have run 16" 7.62×51 rifles unsuppressed? I don't care to thus all three of my 16" medium battle rifles never have suppressors removed. Imagine a suppressor failure on the new Fury round, muzzle blast from an 80,000 psi round with 16" barrel is going to give away your position and be miserable to run. I hand someone a 14.7" M4gery in 6.8 spc II with titanium tube/Inconel baffle full auto rated can and they are stunned at how light, handy, easy to run and its projection of power.
Its like handing them a SIG 9mm duty pistol with an Osprey 9 rectangular can loaded with 147 grain HPs or 1911 with an Osprey 45 running a heavy HP. The cans are so light and ergonomic most say they don't notice it after a few rounds but do find the pistol much more pleasant. While not a big fan of drop leg holsters had one modified that carries a full size pistol with either of the Osprey suppressors and a big SIG 9mm or 1911 with the grip is perfectly placed for bringing into a fight.
The durability issues of the M4 when troops panic as an FOB is overrun by an overwhelming force and the new SIG rifle starts seeing repeated full auto mag dumps by engineers and other troops whose MOS is a trade and not a primary combat role when they subject the M5 to the abuse the M4 saw in battles like what happened at Wannet afraid they are going to find they will fail and fail in catastrophic manner.
M4s with updated modern parts in three or four areas in spc II, M110s in 6.5 Creed with similar improvements just makes sense. Stoner built designed the gas tube to fail before the rifle did but he didn't have 9310 or S7 steel bolts, lobster tail dual spring extractors, improved cam pins, buffers to reduce cycIc rates, Inconel, carbon fiber, etc.
The AR 15s I am building today have 40% more energy on target and are twice as tough as a milspec M4. Adds about $150ish per build if unable to sit out for a sale. In my life never purchased a 0.277" rifle and kept it nor short fat bullets. Have been all about streamlined projectiles and lots of case behind them to get velocity. When I first saw the 6.8 almost thought it was a joke and now building 26th personal AR in it and negotiating on two more 6.8 Minis. If it proves itself better I will run with it.
Built two 6.5 Grendels and was so happy to find fanboys to buy those two barrels and bolts. Have built at two ARs in at least seven cartridges I abandoned. If 22 Nosler (own eight but know 2,000 rounds and get new barrels) didn't smoke throats it would be an easy replacement as specialty 5.56 projectiles don't need re-engineered or retooled to produce. Load up some Noslers with M855a1 or M995 projectiles and will see 300+ fps is another tool to have around.
The M5 needed another decade minimum in development and let M4s be built with improved parts in 6.8 spc II to extend its life. How many NATO countries will follow suit unless we donate them the rifles.
Its like handing them a SIG 9mm duty pistol with an Osprey 9 rectangular can loaded with 147 grain HPs or 1911 with an Osprey 45 running a heavy HP. The cans are so light and ergonomic most say they don't notice it after a few rounds but do find the pistol much more pleasant. While not a big fan of drop leg holsters had one modified that carries a full size pistol with either of the Osprey suppressors and a big SIG 9mm or 1911 with the grip is perfectly placed for bringing into a fight.
The durability issues of the M4 when troops panic as an FOB is overrun by an overwhelming force and the new SIG rifle starts seeing repeated full auto mag dumps by engineers and other troops whose MOS is a trade and not a primary combat role when they subject the M5 to the abuse the M4 saw in battles like what happened at Wannet afraid they are going to find they will fail and fail in catastrophic manner.
M4s with updated modern parts in three or four areas in spc II, M110s in 6.5 Creed with similar improvements just makes sense. Stoner built designed the gas tube to fail before the rifle did but he didn't have 9310 or S7 steel bolts, lobster tail dual spring extractors, improved cam pins, buffers to reduce cycIc rates, Inconel, carbon fiber, etc.
The AR 15s I am building today have 40% more energy on target and are twice as tough as a milspec M4. Adds about $150ish per build if unable to sit out for a sale. In my life never purchased a 0.277" rifle and kept it nor short fat bullets. Have been all about streamlined projectiles and lots of case behind them to get velocity. When I first saw the 6.8 almost thought it was a joke and now building 26th personal AR in it and negotiating on two more 6.8 Minis. If it proves itself better I will run with it.
Built two 6.5 Grendels and was so happy to find fanboys to buy those two barrels and bolts. Have built at two ARs in at least seven cartridges I abandoned. If 22 Nosler (own eight but know 2,000 rounds and get new barrels) didn't smoke throats it would be an easy replacement as specialty 5.56 projectiles don't need re-engineered or retooled to produce. Load up some Noslers with M855a1 or M995 projectiles and will see 300+ fps is another tool to have around.
The M5 needed another decade minimum in development and let M4s be built with improved parts in 6.8 spc II to extend its life. How many NATO countries will follow suit unless we donate them the rifles.
Believe it or not, raising the max pressure to 80,000 psi while keeping the charge weight the same will tend to reduce muzzle blast, not increase it. The reason is that the charge of both loads contain the same amount of energy, but the higher pressure load would use more of that energy in the first few inches of bullet travel. There would be less energy left for muzzle blast. I am not saying that the blast from a 16" 6.8x51 rifle would be pleasant, but it would typically be less with an 80K psi load than with a 60K psi load. The important caveat here is that the same weight of conventional powders are used in both cases. The situation would be different if the 80K load uses an entirely different type of propellant that has a higher energy content.
Joined
·
740 Posts
Interesting. What I am looking forward to is when we find all kinds of specialty military pulled projectiles such as AP or API for the Fury hitting the supply chain. I was able to buy over 10,000 M855a1 pulls and 1,500 M80a1 pulls at very fair prices then found a deal on "belt tails" cheaper than stamdard M855 and M80 milsurp. Those M855a1 pulls in 22 Nosler cases and M80a1 in 300 Win Mag are a bit of fun. Not as fun as API in a 300 Win Mag but much more practical.
Already considering ordering up a 270-08 barrel to put in an AR 10 to begin playing with load development. Broke my foot last week and been having to keep it elevated and iced. Organizing at work (all my ammo and reloading supplies are shipped to work, some even stay so if had chastrophic house fire do not lose all ammo, reloading components, etc) before broke my foot found eleven 30 caliber cans with 500 projectiles each. Ten with M80 pulls and one with 7.62×54 combloc API.
Had moved to house so while recovering decided to resize the combloc API to 0.308". After sized per normal tips migrated from center a tad. Also the bases looked bad like maker didn't care about part of bullet not seen. Set up my pointing die and my Corbin rebated boat tail kit which is designed to be used in conjunction with the pointing die. Now have 512 308 rebated boat tail API way more consistent shape than day made. Swapped rebated BT for standard BT base, made adjustment, pointed and tried bases on the 5,000 M80 pulls while set up.
In the past have cut the tail off specialty bullets a bit then swaged to use in case requiring shorter projectiles. Thus as 277 Fury ramps up production fast QC will be failing rounds and selling to pull companies hopefully soon. The 270-08 should be good to 65,000 psi and 2,800 fps, considered the 270-08 AI but some AI rounds don't feed as reliably and only gain 50 fps. 280 AI seems to do well in autoloaders but we won't be getting 0.284" milsurp pulls.
Have to assume their will be some version of the EPR projectiles for 6.8x51 like the M80a1 as well as the tungsten tip ADVAP almost exact copy that uses a tungsten tip instead of steel. Its stated by the Army the 308 ADVAP will punch holes in a Russian BM-2 armored personnel carrier and carry enough material from bullet and vehicles armor the spall is messy. Also based on weight and design some bullets may be capable to shorten then clean up in swage die for 6.8 spc II use.
The possibilities seem to be wide ranging if past experience reflects to the future. Have so many USGI 308 API its silly. Same with M993 my guess is someone will develop a version of it then as normal will be QC fails on the loading line and different designs Uncle Sugar does not award a contract, can't sell as loaded ammo on civilian market and to the pull companies it will go. Likely be a while before I buy an M5 unless the market finds away to sidestep any patents and trade marks then floods with receivers and parts for us adult Lego guys.
Already considering ordering up a 270-08 barrel to put in an AR 10 to begin playing with load development. Broke my foot last week and been having to keep it elevated and iced. Organizing at work (all my ammo and reloading supplies are shipped to work, some even stay so if had chastrophic house fire do not lose all ammo, reloading components, etc) before broke my foot found eleven 30 caliber cans with 500 projectiles each. Ten with M80 pulls and one with 7.62×54 combloc API.
Had moved to house so while recovering decided to resize the combloc API to 0.308". After sized per normal tips migrated from center a tad. Also the bases looked bad like maker didn't care about part of bullet not seen. Set up my pointing die and my Corbin rebated boat tail kit which is designed to be used in conjunction with the pointing die. Now have 512 308 rebated boat tail API way more consistent shape than day made. Swapped rebated BT for standard BT base, made adjustment, pointed and tried bases on the 5,000 M80 pulls while set up.
In the past have cut the tail off specialty bullets a bit then swaged to use in case requiring shorter projectiles. Thus as 277 Fury ramps up production fast QC will be failing rounds and selling to pull companies hopefully soon. The 270-08 should be good to 65,000 psi and 2,800 fps, considered the 270-08 AI but some AI rounds don't feed as reliably and only gain 50 fps. 280 AI seems to do well in autoloaders but we won't be getting 0.284" milsurp pulls.
Have to assume their will be some version of the EPR projectiles for 6.8x51 like the M80a1 as well as the tungsten tip ADVAP almost exact copy that uses a tungsten tip instead of steel. Its stated by the Army the 308 ADVAP will punch holes in a Russian BM-2 armored personnel carrier and carry enough material from bullet and vehicles armor the spall is messy. Also based on weight and design some bullets may be capable to shorten then clean up in swage die for 6.8 spc II use.
The possibilities seem to be wide ranging if past experience reflects to the future. Have so many USGI 308 API its silly. Same with M993 my guess is someone will develop a version of it then as normal will be QC fails on the loading line and different designs Uncle Sugar does not award a contract, can't sell as loaded ammo on civilian market and to the pull companies it will go. Likely be a while before I buy an M5 unless the market finds away to sidestep any patents and trade marks then floods with receivers and parts for us adult Lego guys.
FWIW, the one existing photo of the 6.8 EPR projectile shows it to be pretty long. If the ADVAP just replaces the steel penetrator with a tungsten one, it would need an even faster twist than the EPR, from what I understand. The 277 Fury specs a 1 in 7" twist rate. Fortunately it may be easier now to get the fast-twist .277 barrels since the introduction of the 6.8 Western, which also needs a fast twist.
Joined
·
1,844 Posts
Yep. Can't wait to see Joe Snuffy toting that beast in triple canopy, wishing for a stripped down M4 w a red dot.
21 - 40 of 60 Posts
Join the discussion
