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If you look at the maximum ordinate across the 3, the 5.56 is the lowest, flattest trajectory, which increase hit potential on partially-exposed targets, like people who don't want to be shot. The 6.5 Grendel with a 123gr is within 3" of it at 300yds for drop, but wind drift is less with 6.5mm/high BC. Retained energy and impact speed on target favor 6.5mm of any of the smaller bore cartridges with similar case capacities. You can exceed the 6.5 Grendel if you go up to a larger case pushing a 6mm at 2900-3100fps, but barrel life is now like a .243 Win.-not acceptable for a military rifle. View Quote A 7mm-08 and a 6.5Creedmore get you even flatter, more powerful rounds but you have to go to an AR-10 action. |
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I really hope you 300 BLK doubters are simply doubting it because you're 5.56 fanbois. At least that would explain why you aren't paying attention to what the cartridge can do. https://www.youtube.com/watch?v=okKLNIDPGI8 View Quote |
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This Buffalo says the gun magazine writer you're quoting is wrong: https://www.youtube.com/watch?v=dfU9bjMUaw8 View Quote |
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For everyone talking about full auto fire, you don't do that as a rifleman, a Team Leader, Grenadier, Squad Leader, or anyone who is carrying an M4 in the line. The only full auto weapons used on full auto are the machine-guns, and in a very controlled burst manner as to not burn your barrels or spend all your lifeline (ammo). There isn't a need to mess with the M4's chambering. There is a need to improve the chambering of our machine-guns, sniper rifles, and a void that needs to be filled with DM rifles-we don't have any or the doctrine to support one. We need a projectile with a BC in the .55 G1/.28 G7 or higher region, that has sufficient retained energy to violently send secondary missiles on impact at distance (retained energy), with better reach than 7.62 NATO and 7.62x54R, that is lighter, with lower working pressure. Make that projectile in the form of M855A1 (already done with 6.5mm), and set up the lightweight LSAT LMG for it, while building an AR15-type DMR/Sniper System for the projectile. Start with desired performance on target (starting with higher hit probability), then work back through the air to the weapon, and how you want that weapon to perform. View Quote I think it would be cool to replace mp5 and mk18 with a short 300blk. Then 5.56 and 7.62 with 6.5Grendel. |
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For everyone saying 300BLK: Are you guys trolling, or seriously retarded? Because 300BLK for an individual service rifle cartridge is pure retardation. You just cut your hit probability from 5.56 NATO way down, while reducing barrier penetration and armor defeat capability substantially. You also cut your effective range down. Why anyone would openly advocate for 300BLK for general issue is beyond me. It's a special application cartridge with a very limited role suppressed, to allow some of the same capabilities of the MP5SD for certain units, not a general issue infantry rifle cartridge. View Quote |
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6.5 Grendel surpasses it in every way aside from closer range (0-300 yards) muzzle energy. View Quote View All Quotes View All Quotes Quoted:
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What happened to 6.8SPC 6.5 Grendel doesn't do nearly as well from short barrels. |
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What happened to 6.8SPC View Quote Nobody really wanted it, nor did they ask for it. The projectile diameter is way too large for how long the case is, so you get poor BCs. It's basically a bigger 5.56, that goes slower, with more trajectory, less magazine capacity, and the same or worse wind drift, making it unsuitable for DMR role especially. Another less-known cartridge that SF started using before M855A1 was the Barnes 70gr TSX Brown Tip, which put dudes' dingle dangle in the dirt even from 10.5" guns, and they had Mk.262 for DM role as well. That eliminated any desire for 6.8, let alone the antics of the proponents who tried to shove it down SF's and JSOC's throat, especially after the kabooms JSOC had in initial fleet testing. Then it was taken to the FBI ballistics lab and a fraud was perpetrated, resulting in the FBI head ballistician saying if he ever saw a Federal LE agency come to him with 6.8, it was going to be denied on the spot, he had never seen such a lame attempt at fraud before, with regard to attempting to pass off a varmint projectile as an OTM for the terminal ballistics testing. They then went to the UK and told the UK MoD small arms folks that this was the US's next service rifle cartridge, and that the MoD had better get the tooling NOW or else they would be left in the dust, headed off to NATO next gents. Brits said, "That's not how any of this works." Basically, the guys advocating it burned every bridge they came in contact with, engaging in unprofessional conduct as a rule, with no real working knowledge of how cartridges should be designed, tested, or implemented. At least one of them was fired from his job as a result. |
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6.8 SPC was made to be extremely efficient from short barreled guns and still have effective performance from 0-300 yards. It performs that role quite well and with improvements to bullets etc it can hang with the Grendel at longer ranges. 6.5 Grendel doesn't do nearly as well from short barrels. View Quote |
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So they're looking to replace the 7.62? Seems like the 6.5Grendel could do it? Why not replace both systems with the 6.5Grendel? Is it a carrying weight factor? I think it would be cool to replace mp5 and mk18 with a short 300blk. Then 5.56 and 7.62 with 6.5Grendel. View Quote We don't yet have a proven design for a rifle that fires LSAT cartridges. Everything should hinge on this, or polymer cases with metallic heads. That's what they are attempting with .260 Rem. A hybrid polymer/metallic case in conventional rifle designs (M110 SASS). .260 is still too big for the rifleman and every other duty position that currently carried an M4, because the mags are much longer (COL), with less capacity. It's extremely difficult to find space for an equivalent basic load for the soldier when your mags are the size of SR25 mags. |
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6.5 Grendel surpasses it in every way aside from closer range (0-300 yards) muzzle energy. Higher BC of the Grendel bullets means higher retained energy at greater distances despite marginally less energy at the muzzle. View Quote View All Quotes View All Quotes Quoted:
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What happened to 6.8SPC More energy at the muzzle, less wind drift, same drop initially, then stays flatter, with more retained energy as the distance increases, with way less wind drift. |
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6.8 SPC was made to be extremely efficient from short barreled guns and still have effective performance from 0-300 yards. It performs that role quite well and with improvements to bullets etc it can hang with the Grendel at longer ranges. 6.5 Grendel doesn't do nearly as well from short barrels. View Quote View All Quotes View All Quotes Quoted:
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What happened to 6.8SPC 6.5 Grendel doesn't do nearly as well from short barrels. It has literally zero advantages over 6.5 Grendel from short barrels. Please show me one verifiable example of how it performs better from a short barrel. |
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Don't see any buffalo being shot with a 300. Bison maybe. The only logical choice is to go with 460 .
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All things will soon be .260/6.5 and .338. There's no use in fighting it, it's coming. .22/5.56 and .30/7.62 are dinosaurs. Embrace the new superior calibers. View Quote In the familiar metallic cartridge- nitrocellulose propellant paradigm, switching from 5.56 for general issue is dumb. Even switching GPMGs and DMR-type rifles from .308 to a 6.5mm cartridge would offer a pretty modest leap in capabilities compared to the investment. A hot .338 round would probably be worth doing in a "light heavy" MG or even electric/rotary gun for static and vehicle-borne use, as well as a sniper rifle. |
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In some form factor like LSAT or caseless or liquid propelled ceaseless or EM-driven, sure. In the familiar metallic cartridge- nitrocellulose propellant paradigm, switching from 5.56 for general issue is dumb. Even switching GPMGs and DMR-type rifles from .308 to a 6.5mm cartridge would offer a pretty modest leap in capabilities compared to the investment. A hot .338 round would probably be worth doing in a "light heavy" MG or even electric/rotary gun for static and vehicle-borne use, as well as a sniper rifle. View Quote |
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For everyone talking about full auto fire, you don't do that as a rifleman, a Team Leader, Grenadier, Squad Leader, or anyone who is carrying an M4 in the line. The only full auto weapons used on full auto are the machine-guns, and in a very controlled burst manner as to not burn your barrels or spend all your lifeline (ammo). There isn't a need to mess with the M4's chambering. There is a need to improve the chambering of our machine-guns, sniper rifles, and a void that needs to be filled with DM rifles-we don't have any or the doctrine to support one. We need a projectile with a BC in the .55 G1/.28 G7 or higher region, that has sufficient retained energy to violently send secondary missiles on impact at distance (retained energy), with better reach than 7.62 NATO and 7.62x54R, that is lighter, with lower working pressure. Make that projectile in the form of M855A1 (already done with 6.5mm), and set up the lightweight LSAT LMG for it, while building an AR15-type DMR/Sniper System for the projectile. Start with desired performance on target (starting with higher hit probability), then work back through the air to the weapon, and how you want that weapon to perform. View Quote |
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.30-378 Weatherby is the best caliber solution for the DMR/GPMG role
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M240 is way bigger than you would need for a 1950s design chambered in 6.5 Grendel. If you did double down on a 1950s design and chamber with a metallic case cartridge, the weapon would be like a Stoner 63, Stoner LMG, SAW, or Ultimax. Chamber pressure of 6.5 Grendel is way less than 7.62 NATO, as is case capacity. You just don't see throat erosion like 7.62 NATO, which isn't particularly fast unless you go cyclic. LSAT 6.5mm is where it's at for an LMG, with smaller case than the 7.62 LSAT, and lower working pressure. View Quote View All Quotes View All Quotes Quoted:
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DMR, maybe. Those 6.5 cartridges burn out barrels fast. (I may not be precise on the velocity but I'm not far off) If you did double down on a 1950s design and chamber with a metallic case cartridge, the weapon would be like a Stoner 63, Stoner LMG, SAW, or Ultimax. Chamber pressure of 6.5 Grendel is way less than 7.62 NATO, as is case capacity. You just don't see throat erosion like 7.62 NATO, which isn't particularly fast unless you go cyclic. LSAT 6.5mm is where it's at for an LMG, with smaller case than the 7.62 LSAT, and lower working pressure. |
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IMHO there is no need to replace the M16/M4 and 5.56 until caseless ammo, or another major small arms evolution, becomes reality. Surely caseless ammo can't be that far off, they were fielding prototypes of it in the 80's for heaven's sake!
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somehow I got confused and though he was talking about 6.5 Creedmoor, which a lot of people have been doing lately. My bad. But isn't my info still good if we're talking 6.5 Creedmoor. View Quote View All Quotes View All Quotes Quoted:
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DMR, maybe. Those 6.5 cartridges burn out barrels fast. (I may not be precise on the velocity but I'm not far off) If you did double down on a 1950s design and chamber with a metallic case cartridge, the weapon would be like a Stoner 63, Stoner LMG, SAW, or Ultimax. Chamber pressure of 6.5 Grendel is way less than 7.62 NATO, as is case capacity. You just don't see throat erosion like 7.62 NATO, which isn't particularly fast unless you go cyclic. LSAT 6.5mm is where it's at for an LMG, with smaller case than the 7.62 LSAT, and lower working pressure. LSAT makes the M240 obsolete. If anyone is still trying to double-down on metallic cartridges for LMGs and GPMGs, it's a wasted effort. Whether looking at vehicle-mounted ( to include aviation) or man-portable belt-fed machine-guns, Cased Telescoping is the way to move forward. It solves so many problems that metallic rifle cartridge technology has. The main hurdle is establishing the economy of scale with production of the medical-grade polymer cases and plugs. |
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Which part do you not understand? The MPBR is dependent on bullet and powder selection. 300 yard hits are easy as pie with a 125gr OTBT bullet. As to the rest, it is common knowledge that the BCG and Magazines ar identical between 5.56mm and .300 blk. As a matter of fact, a simple barrel and gas tube swap is all that is generally required to change calibers between the two. View Quote |
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Wouldn't 6.5 Grendel make more sense? Retain the smaller magwell size and weight with far superior ballistic performance and longer range capability than 5.56. I cant imagine using a 6.5 Creedmoor carbine to do room clearing, how fucking loud would that be jesus christ. View Quote |
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The US doesn't push things through NATO first. We push things onto NATO after, like with what we did with 7.62 "light rifle". View Quote |
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I really hope you 300 BLK doubters are simply doubting it because you're 5.56 fanbois. At least that would explain why you aren't paying attention to what the cartridge can do. https://www.youtube.com/watch?v=okKLNIDPGI8 View Quote View All Quotes View All Quotes Quoted:
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I really hope the 300 blackout people are trolling. https://www.youtube.com/watch?v=okKLNIDPGI8 |
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What method will be used to keep a rifle cool that uses polymer cases?
Brass does a great job of taking heat with it as it's ejected from the rifle. |
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This. View Quote For standard rifles it's a horrible choice. Lets go back 44-40 Long colt or 30-30 while we are at it. The Russian 9x39 actually serves a similar purpose and is much better than 300BO but even they realize it is for very mission specific reasons like sabotage, reconnaissance, or CQB. |
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The headlines are misleading. The PowerPoint slides I saw about the caliber testing pertaining to .260 Remington/6.5 Creedmoor are focused on a new caliber for the 7.62mm M110 rifle- not the 5.56mm M4. https://scontent-lga3-1.xx.fbcdn.net/v/t31.0-8/fr/cp0/e15/q65/18216598_1562047030494237_6607329628611495311_o.jpg?efg=eyJpIjoidCJ9&oh=fd72e6bbfcfb387e474eaa4384430f0f&oe=59BB6EAE View Quote View All Quotes View All Quotes Quoted:
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It also seemed, in my research, that 6.5C really needs a longer barrel to take full advantage of it's potential. So what, are we going back to a 20"+ barrel for the standard issue rifle, now? https://scontent-lga3-1.xx.fbcdn.net/v/t31.0-8/fr/cp0/e15/q65/18216598_1562047030494237_6607329628611495311_o.jpg?efg=eyJpIjoidCJ9&oh=fd72e6bbfcfb387e474eaa4384430f0f&oe=59BB6EAE They are way heavy for an individual carbine. |
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What method will be used to keep a rifle cool that uses polymer cases? Brass does a great job of taking heat with it as it's ejected from the rifle. View Quote Brass is a major conductor of electron flow, so heat from the cartridge transfers into the steel chamber, barrel, and any components that touch the barrel. Polymer, on the other hand, absorbs heat and electron flow, more as an insulator. Polymer cases suck heat into the case and transfer substantially less heat to the barrel. |
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Well, I searched for M16, REPLACE, REPLACEMENT, and a couple others. I figured if that wasn't good enough, we have a whole team of tier 1 specialists to police any dupe. View Quote View All Quotes View All Quotes Quoted:
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No link, no dupe. Even though there are 87 fucking threads on this already and all fucking OP needs to do as a fucking paying team member is use the fucking search function and entering fucking ARMY fucking RIFLE. Fuck! ETA: It would be nice if the .mil finally adopted a flatter, harder hitting round. |
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The next big war will likely be in a large urban area. I can't think of one advantage 6.5C sized guns give in that environment. If it was me going to war, I'd want something with more ammo capacity than 5.56, lighter ammo, and flatter shooting if possible. Caseless 6mm maybe? Once again, we're preparing for the last war, ignoring the future. View Quote |
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