Posted on 01/29/2024 8:51:48 AM PST by Red Badger
The comparison is laughable. They’re about as similar as a Bowie knife and a harpoon, both of which are stabbing weapons but that’s where the similarities cease.
The 6.8 SPC was created by snake eaters to cure the limited terminal effects problem of the 5.56 round in short (<11”) barrels, and it had to be compatible with STANAG 5.56 magazines.
The 277 Fury was created to meet a future need to defeat body armor on the conventional battlefield. And they threw out all the rules and conceded it would take an entirely new platform, to include the magazines. They went to the absurd length of using an 80,000 psi round, which requires a 2-piece cartridge case with a steel case head (because brass couldn’t have withstood that much pressure). And even with melonited barrels, they probably won’t last 1000 rounds.
The criteria behind their creation were completely unrelated.
It also bears mention this author’s CV doesn’t mention anything about law enforcement or military experience, so one must question what it it that qualifies him to pontificate as to which would make the better HD/SD round.
This article is about as useful as the two cartridges. Money wasted to re-invent the 7mm Mauser or the .280 Rem/7mm-06. What a crock.
F=MV2. Recoil goes up with the square of the velocity change, assuming both projectiles have the same weight.
I have no first hand experience, but from what I've read the .277 Fury brass and .277 Fury Hybrid case have a very noticeable difference in felt recoil.
Oh, wait, I see what you’re saying. It’s a typo...............
= = =
Better yet!
A Typo .227
Now I really want one. Before anyone else at the range.
I have decades of shooting these platforms. Yes, like I stated, I can tell the difference. But its not enough to matter in terms of changing how you shoot. Your F=Ma (not F=MV^2) is not accounting for the buffer assembly absorbing a large portion of the recoil in the AR platform.
Isn’t bullet velocity the culprit in barrel degradation? I see a listed muzzle velocity of 2830 fps. That’s not excessive.
Using enemy soldiers’ ‘body armor’ as an excuse, Yes............
F = ma = d/dt(mv)
KE = (1/2)mV2
I think what you're trying to say is:
m1v1 + m2v2 = m1V1 + m2V2
Given that m1 and m2 (bullet and rifle) are both at rest before firing (ie: v1=0 and v2=0) then
m1V1 = -m2V2
Which is to say that after firing, the momentum of the gun and of the bullet are equal in magnitude but opposite in direction.
Therefore, in general recoil varies linearly (not geometrically) with bullet mass and bullet velocity. It is left as an exercise to the reader that for a given cartridge and load, heavier guns will have a smaller V2 and consequently less felt recoil.
The RFI/RFP/contract award for this new platform, and its requirements, were driven by the fact that our adversaries in the field can now get body armor easily and that makes the current platform (M4 or other M-16/AR-15 family of variants) less effective.
Soldiers in the field push these requirements based on battlefield experience.
In physics, you don’t get something for nothing. Ever. Even from buffer assemblies.
Buffer assemblies trades the magnitude of the recoil impulse for the length (in time) of the recoil impulse. For most shooters (well, for me and anyone I’ve ever discussed it with), a “shove” recoil is more tolerable than a “slam” recoil.
No thanks, I’ll take a 270 Winchester in A Mauser bolt. Thanks for asking.
Put the gas driven moving mass (BCG) and recoil spring into that system. Its not as simple as Newtons action/reaction experiment, from the perspective of the felt recoil of the operator.
True
Buffer assemblies trades the magnitude of the recoil impulse for the length (in time) of the recoil impulse.
Partially true. The stored energy in the spring is also used to drive the BCG forward and load the next round.
👍
See also #50.
#48 is a “first approximation”, and at least gets the basic mathematical relationships correct. “Felt recoil” is a squishy term, which requires discussion of Impulse, Torque, and various structural of the firearm to address.
The recoil energy of the 277 is about the same as a 30.06. In a light rifle this is ridiculous. They want every troop flinching? If it’s for special uses only then there’s little reason to come up with a new cartridge at all.
Follow the money.
See 53
The world is full of 'squishy' :)
See 49
The stored energy in the spring is also used to drive the BCG forward and load the next round.
True, but not relevant to the backward recoil impulse. The bolt/BCG being driven forward introduces a new impulsive force which further drags the whole business out in time.
BTW, you've just given me an idea for suggestion to "Ballistic High Speed" or "The Slow-Mo Guys" ... their kind of high-speed video of an AR-15 (or some such) firing when shouldered, and when hanging freely. I'd like to actually SEE (at ridiculous frame rate) the recoil motion of a rifle. A gas-operated semiauto should be very different from a bolt-action.
Which is one of the reasons why the perceived recoil of my Remington 600 in .308 is significantly more than an AR-10 firing the same ammo. There is also the lighter weight of my 600.
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