It was ever thus.
Not so:
Posted on 04/08/2008 5:33:15 PM PDT by LSUfan
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I'm happier with my longer but lighter M16A1 version, whose longer gas tube allows more room for buildup of corrosion from foreign surplus ammo, old GI M193 ball, or my crappy reloads. But I have hedged my bets sufficiently to have a second upper available for it with a shorty 1:7 twist barrel, just in case I find some 62 grain M855/ NATO SS109 or 77 Grain MK 262 Mod 0 5.56MM lying around on the ground.
Of course, I could throw another lower together for the shorty barrel, and have another rifle around. Then I'd want to have a spare available for it, then I'd probably come up with another lower for it, then another spare, usw, usw.
Neat info-
The 556 62 grn does not do 3240-more like 2750-2800 from an M4
The 6.8 fails to meet that 2800 fs as well-more like 2450-2500 from a 14 inch M4
Got to compare apples to apples. Remember what I stated in my post-’No free lunches for the Dogs of War”.
It would be nice if the 6.8 actually did perform that well from a 14 inch M4-the truth is not in your quoted table, likely it was derived using a 24 inch barrel or maybe even longer. 10 inches of added length would add approx. 25-40 fs per inch, or 250-400 more velocity than a 14 inch tube. I would not expect any more than my estimated 2450-2500 fs.
Also, given the design of the M4, the point blank figures should be using 14-15 inches above and below the point of aim-the military expects troops to aim center mass and on a standing enemy, that total target height is around 28-30 inces (hips to collar bones)
The M16A2 point plank range is 360 m with M855 ammo (rear sight set at 300+1 click, zeroed at 42 m, then RS backed to 300) Bullet path is approx 15 inches high at 250m, crosses line of sight at 300m and falls below 15” low at approx 360m. M4 5.56 is zeroed in similar fashion, with max PB at around 300m IIRC.
See FM 23-5 M16/A1/A2, M4, M4A1 Rifle Marksmanship for data tables etc. I do not know of any comprehensive M4/6.8 data, just ballistic software figures.
My estimation for the 6.8/M4 is that is would not significantly add PB range, compared to the M855/M4 (again, same platform, different caliber).
Would be interseting to see actual test data.
There are a few mods tha that M16 family could use to improve serviceability.
However, the platform is a fine tool as it is. Adding a piston driven system would not be cost effective, nor necessary. It works.
Soldiers have died because the Garand (the world’s greatest battle implement)failed as well.
Too many older troops (no disrespect intended, believe me) expereinced major life-threatening problems with the M16 in Vietnam. The M16A1 pretty much solved those functional problems-chrome lined bore and chmaber, slight mods to the externals,and more QC in the ammo production process. Each susequent upgrade has resulted in a more lethal, user friendly modular system that plain works.
It's been the standard rifle in one version or another since 1967. We may have squeezed about as much out of the system as can be managed, but a couple of additional improvements do come to mind. With more than 10 million produced and most of those still in service, we can expect that one way or another, the M16 is going to be in service somewhere in the system until at least 2025, probably to the midpoint of the XXI Century.
If the answer is "Yes," the fixes suggested, namely changing from open gas operation to piston actuation, don't seem all that daunting. How do we go for it?
It's going to take more than that, actually, quite a bit more. See my comments about the magazine design in the post above. And the M16 is not particularly lefty-friendly, the *Brunton Bump* on the side of the M16A2 receivers to prevent ejected brass from hitting left-handed firers in the eye not withstanding. There have been a couple of troops blinded in one eye by ejected, spinning brass, not a real desirable feature in a combat weapon.
If the answer is "No," should we replace with the HK416?
Maybe some of them could be replaced with the HK416; I don't think it's ever going to be an all-services rifle, even though the SpecOps community likes it. Neither is the XM8 *just* the answer, nor the German G36s that are the weapon used by the Pentagon security detail.
How do we get that done?
I would strongly suggest a Divine religious miracle.
Some changes are obviously in the wind, but we are also obviously in the "confusion" stage. As far as the caliber change goes, both of the weapons in question are adaptable ... I think.
So is the M16, though it's better handled as an armorer's project during depot rebuilds with them. That offers at least one possible use for the 4.5 million old M16A1s in the national inventory, some of which the Navy has recycled back into M4A1s, and many of which have gone to Israel. The M9 issue is perhaps more complicated. IMO, this would be a fine weapon, if fed with the right ammo, which is forbidden to us by NATO and the Geneva Convention. Can we change that? If not, then what? If not, with what do we replace the M9?
And the M12, used by those for whom the M9 is overly bulky. Oh, and those SIG226s used by the Navy Seal teams.
We need specific people in Congress who can help sort this out. Do we have 5 people we can trust?
The problem is, they have to be both trustworthy AND knowledgable, or at least have at least one staff member in the right position to understand the issue. We've got one such running in Indiana's 9th District. And Chip Pickering from Mississippi's Third District knows what he's talking about, based on a conversation I had with him when he visited the Katriuna relief efforts. But I understand he's not running for reelection.
My estimation for the 6.8/M4 is that is would not significantly add PB range, compared to the M855/M4 (again, same platform, different caliber).
Would be interseting to see actual test data.
Remember that the Soviets, who'd been fielding the AK47 and AKM with a 16-inch barrel since the early 1950s, have also had unhappy users insofar as the smaller bullet of their own downsized 5.45mm AK74- including MikTim Kalishnikov hisself.
What I'd really like to see would be that bullet from the 6.8 SPC utilized in the 5.45mm case, thereby suitable for either the 5.56x45mm-length actions, or the former SovBloc &.62 M43 and 5.45 weapons.... and maybe even the existing magazines. I haven't run the ballistics of the reworked round yet, though I'm sure the Soviets did when they worked out the 5.45 cartridge. But I have offered the idea to someone in that line who's interested.
Correct me if I am wrong.
The AK47 or AKM barrel is usually 16.1 inches long. That of the SKS/CKC Siminov Carbine is 521 MM/ 20.5 inches in lenght. Best of all, the RPK Squad Auto version has a barrel 23.5 inches long, offering both a little better velocity and a longer sight radius than its shorter cousins.
It was ever thus.
Not so:
If we could only travel in time.......:o)
LOL! Is that guy on the lower right having mag problems??! :)
Okay: First off, the 10mm is not the same thing as a 40. The forty is called the shorty forty because it is actually a shortened 10mm case because the full size round was beating the frames of the pistols to death and doing a job on the sensibilities of folks that fired the round. Also, the 10mm isn't what you'd call a widely available round and neither is the 40. As opposed to the 45 and 9mm which can be found everywhere on the planet and in great quanities. Maybe there is a reason for that? Anyway, that's useful in logistics (my secondary military specialty) when you run short and maybe have to make a local purchase. We used to do that all the time for various types of goods.
Perhaps the most spectacular example of local purchase is the first Gulf War when Special Forces discovered that wheeling across the desert in the HUMVEE was hazardous to your health because only Americans drove them so every sniper and jihadi with an RPG was looking for those. But in a Land Rover, Range Rover, or Toyota Land Cruiser you could be mistaken for a wandering mullah or imam and shooting at those could make you wind up in hell. So here went the SOCOM guys buying up the entire inventories of whole dealerships and screaming across the desert in these fully loaded (pun) luxury land yachts with the CD's blaring inside and the A/C on full blast.
Back on topic. The 10mm is inadequate in so many practical ways but not in the man stopping department. Too bad that's not enough. The Hague accords aren't going to change so bullet configuration is going to remain FMJ and the 10mm is far more likely to over-penetrate than either the 45 or the 9mm, bringing innocent lives into harm's way. The result is every politician's nightmare collateral damage.
Better to use a suitable platform like the USP or H&K45 both of which use a mechanical system to reduce the felt recoil. It's a DA first shot which beats the 1911 all the way around for making sure the shot is an intended action and that reduces that ~shudder~ dreaded collateral damage.
I agree with the idea of starting folks out on a 22 and working up. I use that whenever I have a novice in one of my ccw classes(I've been an NRA certified Instructor for about 20 years). The truth remains thusly: In a FMJ configuration bigger bullets are needed for a decisive stop. The round that meets the need best all around including the militarily critical area of logistics is clearly the 45 ACP.
Overpenetration? You’re a nut. Nobody cares about overpenetration from a rifle. So why should they care about overpenetration from a pistol?
Archy;
There are are 6X223, 6.5X223 and 7X223 wildcats which generally are poor performers with bullets of any appreciable increase in mass/BC.
The 6mmX223 can push a 70 grn 6mm bullet at about 2700fs, much less effeicient than the 77/80/90 grn SMK already in use in the 223/556, don’t even try seating a 107 SMK with the expectation velcoity past 2000fs!
Again, no free lunches-trade capacity for bullet diameter.
You kinda lost me-use the 5.45x39 mmm with a .277 diameter bullet? You would be losing more case capacity than if you wnet with a 6.8x223 (45mm case), I think.
There are a few dedicated 6mm cartridges being used in High Power Competition in the AR-the 2007 National Match Rifle Champ (Carl Bernosky) used a 6mm Hagar, not too sure of the case length, but the OAL must be AR mag length for use in the rapid fire stages....
Bottom line is the 233/5.56 mmx 45 is probably the most mature cartridge since the 308/7.62 (full course 200-600 yd match competition drives designs to the edge of performance, occassionally past it!)
Nothing to stop you from creating a 6.8 x39 mm, but it will be a lessor cartridge than the 6.8 or the 5.56 already are;
Rough interpolation would indicate that it could not exceed ~2450-2500Fs (gas law rule of reduction of bore diameter compared to existing rounds always yeilds less velocity from a similar platform profile) with a 115 grn bullet, and AK/SKS platform accuracy is nothing to boast about either.
The 5.56 with advanced bullet design (77 SMK) still is the best combination of performance, capacity, reliability and accuracy compared to the other combat options.
If you want a 30 cal (762x51, 762x63) performance step up to a proper platfrom, remember.... no free lunches for the dogs of war! (Democrat party planks notwithstanding....)
Molom Labe!
NO!
If the answer is "No," should we replace with the HK416? How do we get that done?
First take the ~spits to the side~ politicians out of the process! Listen to the troops not some politician or senior officer either one of which (speaking of generals who are superior politicians in their own world) might be taking kickbacks under the table from the arms manufacturers or folks with serious monetary connections to the contracts. Like companies who manufacture accessories for the M4 that would need to be retooled in a new rifle.
Get a bunch of troops and test the crap out of the weapons under real world conditions and situations from the testers experiences. Once the 416 is confirmed as meeting the needs of the service determine if there must be any variations for special circumstances (like tankers or aircrew) and issue the contract.
But, in the 45s defense, there is evidence to suggest that muzzle energy isn't a perfect indicator of stopping power. for instance, the 45 seems to do much better in the real world than ballistic data would predict.
But you asked about ballistics, not real life gun fights. AS far as balistics are concerned, the 45 is really pathetic. Well, not as pathetic as a 38 special. But not very good. Not very good at all.
First of all, is that all you took from my argument? I posted overpenetration as a potential consequence to MOUT operations (aka urban warfare) where a round that sails clean thru may hit either a civilian or worse another troop. But hey taken from a soldier's point of view I don't think I'd lose much sleep over the former (maybe sleep a little sounder if I was able to drop two bad guys for the price of one) and we all knew the risks when we signed on the dotted line. But the folks who make the decisions in the big five sided puzzle palace absolutely cringe at the thought. So you seized upon the most minor point of mine to argue and then you attack me personally. Sounds like a liberal with the weak side of the argument. Can't argue on substance. Go for the "below-the-belt" shot, confuse the issue with small points and hope nobody notices that you slimed out of the issue in all the confusion.
C'mon, you've been around FR almost as long as I have. You're well traveled (I saw your about page) and well read. Don't stoop to the juvenile tactics of the left. You're way better than that.
Feed reliability partly comes from the fact that bullet diameter is less than case diameter.
But, I was thinking earlier that maybe a good idea would be to neck up a 223 to maybe a 25 caliber, then load a sabboted 22 caliber bullet in it. Also, very fast burning powder, polygonal rifling, increased head space, less twist, much higher chamber pressures, aluminum cases or steel if necessary and a hammerforged stainless barrel. Heck, make it out of monel or nikasil or whatever stands up better than stainless. Invent a new metal if necessary. Whatever it takes to increase pressure and velocity.
But not at the expense of accuracy. Some of the ideas I just threw out may hurt accuracy.
Just right offhand, I can't immediately recall any round that has a bullet diameter greater than the case diameter....
Very funny. I meant to type “greatly less than” or “significantly less than”.
The 6mmX223 can push a 70 grn 6mm bullet at about 2700fs, much less effeicient than the 77/80/90 grn SMK already in use in the 223/556, don’t even try seating a 107 SMK with the expectation velcoity past 2000fs!
Indeed. One of the contenders [submitted by Gene Stoner's ARES, I believe] during the SAW trials used a 5.56mm case with the neck opened enough to take a 6mm bullet. But I think the idea was to get a tracer bullet with a tracer burnout distance beyond 900 meters as much as for other external ballistic improvement. It's of course a lot easier to make a barrel change on a Minimi/M249 SAW than on a M16 rifle.
Again, no free lunches-trade capacity for bullet diameter.
An improvement on one side of the scale will certainly be met with a tradeoff of some sort elsewhere, unless there's a major materials/technology breakthrough. No argument from me about that.
You kinda lost me-use the 5.45x39 mmm with a .277 diameter bullet? You would be losing more case capacity than if you wnet with a 6.8x223 (45mm case), I think.
Correct. But it would be an improvement for the AK family platform, probably using existing AK74 magazines. At the very worst, magazines for the 5,56x45 AK variants might be used, or new ones developed.
There are a few dedicated 6mm cartridges being used in High Power Competition in the AR-the 2007 National Match Rifle Champ (Carl Bernosky) used a 6mm Hagar, not too sure of the case length, but the OAL must be AR mag length for use in the rapid fire stages....
Yep. And 6mm Tubb, the 7,62x39mm/M43-derived6mm PPC,and there's 6mmAR, intended specifically for the M16/M4 platform. And stepping things up a notch, the 6,5 Grendel.
Bottom line is the 233/5.56 mmx 45 is probably the most mature cartridge since the 308/7.62 (full course 200-600 yd match competition drives designs to the edge of performance, occassionally past it!)
Nothing to stop you from creating a 6.8 x39 mm, but it will be a lessor cartridge than the 6.8 or the 5.56 already are;
Yep. But it could well be an improvement over the 5.54x39.5 Soviet
Rough interpolation would indicate that it could not exceed ~2450-2500Fs (gas law rule of reduction of bore diameter compared to existing rounds always yeilds less velocity from a similar platform profile) with a 115 grn bullet, and AK/SKS platform accuracy is nothing to boast about either.
Concur, for the most part. Though accuracy concerns are more an issue with rifle accuracy than required beaten zone effects for a SAW, as per the US *Project Salvo* efforts of the 1960s-'70s.
The 5.56 with advanced bullet design (77 SMK) still is the best combination of performance, capacity, reliability and accuracy compared to the other combat options.
If you want a 30 cal (762x51, 762x63) performance step up to a proper platfrom, remember.... no free lunches for the dogs of war! (Democrat party planks notwithstanding....)
Molom Labe!
I'm not so certain it's all that cut-and dried. From the British thoughts circa 1910 regarding a possible pre-WWI .303 SMLE replacement that became the Pattern 13 Rifle of , to Pedersen's .276 cartridge used in the first Garand rifles, to the Post-WWII British circa-1945 Armament Design Establishment's Ideal Cartridge Panel development of the .280 cartridge [280 Mk1Z/(7 x 43 mm)]for the EM1 and EM-2 designs that would have become the British *Rifle No. 9* NATO rifle, there's been a lot of interest in something in there somewhere between a .22 and .30 caliber hole. Oh yeah, and the old Navy/Marine straight-pull Lee rifles and Colt Potato Digger LMGs of the Boxer War period. 
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