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SIG-Sauer, NOT an American company no matter how many facilities they have in the USA, has convinced the Army that they have the special sauce to make their new rifle.
That includes ammunition.
6.8x51mm. A 135gr, .277 caliber bullet lobbing at [not specified] velocity from a 13.5" barrel from an 80k psi chamber. If you fire it from a non-NFA 16" barrel you get about 3,000 fps.
That's about the same as everyday common .270 Winchester in a 24" barrel at the MUCH lower chamber pressure of 65k psi.
Willard immediately noticed that 6.8x51mm is, in basic strokes, a necked down 7.62x51mm round.
7.62 NATO runs an even lower pressure than .270, a mere 60.2k psi.
Which made us wonder... Did we need to develop a whole new round to do this?
I'm not sure, yet.
First elephant in the room is the pressure is likely due to the need to get acceptable performance from the round from the 13.5" barrel. That length is almost definitely determined by keeping the overall length of the gun manageable with the standard issue sound suppressor.
The numbers for that acceptable performance are not jumping out at me searching the intertubes, but...
I'm finding nothing about what the XM5 does at the muzzle.
There's nothing earth shattering about the 16" performance other than it doing it 8" earlier than every other round doing it. That's because of the pressure.
I am very skeptical of the 12k barrel lifespan with those chamber pressures.
I am not skeptical of SIG being able to deliver the hybrid cases cheaply. I can think of a couple of ways to make them from the cut-away models they've shown that would be economical.
No doubt the muzzle blast will be spectacular. Way beyond an M44 Mosin.
ReplyDeleteThe suppressor ought to help that a little... but It probably isn't going to be nearly the sound or flash level of something like .300 Blk
DeleteThe suppressor keeps the muzzle blast lower than what an M4 puts out. I haven't seen any YouTubers firing one without it yet.
DeleteShell Shock Technologies (aka Shell Tech) does a two part 9mm case - aluminium case head and nickel steel "barrel". I have been watching for them to offer a .38 Super before I try them.
ReplyDeleteI suspect the tech in the M5 ammunition to be similar. After all, why re-invent the wheel?
Here's a thought about this new rifle. Obviously politically Sig-Sauer is going to be under tremendous pressure not to release a civilian market version of this, even one semi-auto and with a non-NFA 16" barrel. If the US military switches over entirely to this new rifle and abandons the M4 and M16 (which is unlikely to happen at least soon due to budget concerns if nothing else). At that point, does the M4 and M16 suddenly become not a "military style" rifle? Seems to make some of the anti-gunner positions on not allowing "weapons of war" for civilian sales even more shaky. Of course I know they will continue to hate ARs just on principle. But it does seem like there is a lot less media vitriol directed towards the AK platform given that it isn't what the US military issues.
ReplyDeleteThe 13" plus suppressor, $7,999 per copy MCX Spear (suitable for loitering around a mass shooting in style) is already available to "Select Dealers". I am pretty sure that includes a happy-switch so it's a Kings Man Only gun.
DeleteThe version for us great unwashed is prolly nine months out. $3k or so, I imagine.
And if I want an AR-10 style rifle, I thing I'll just get an AR-10 in .308 and save some money.
I'll just mumble "EM-2" and ".280 British".
ReplyDelete