Infantry Combat Equipment (non-firearm): Vests, Body Armor, NVGs, etc.

TerraN_EmpirE

TerraN_EmpirE

Tyrant King
Bltizo said:
That said, the camo scheme does look very similar to what the supposed new Type 17 camo scheme kind of resembles, so who knows... I just wish we had some more legitimate and detailed information about Type 17.

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It's basically commercial Multicam no if ends or buts. US Military Multicam designated as OCP has a slightly darker color way because of changes in the dyes to make it more effective in the NIR.
 
I

Iron Man

Major
Registered Member
TerraN_EmpirE said:
Accuracy is not a product of barrel length, Velocity is a product of barrel length. Velocity can impart range.
Accuracy in a rifle is the ability to repeatedly hit a target. when we talk about MOA we are not talking about single shots but generally a grouping of shots. The proverbial "Ragged Hole" is the dreamed of sub MOA group where in all the successive shots have more or less hit the same spot and just made a bigger hole in the target.
Velocity is the product of the propellant burn of a bullet. that burn turns the propellant into gas which expands in the chamber bore and barrel pushing the projectile down the length. However as this happens the barrel and chamber of the weapon are absorbing some of that energy. they do so in 2 ways first using it to cycle the weapon. and second because the projectile and gasses are in the barrel, bore and chamber as well as inside the rifling of the barrel vibration.
Vibration is the Enemy of Accuracy.
Now consider a very long thin tube of material. If one end is braced the other tends to be a bit limp. The Shorter the tube though the less it bends. until it's fairly short when the tube is very stiff. This is because of the density of materials vs the weight spread across the length. now if energy is imparted into the tube the limp potion will move and flex.
This works for a barrel as well. The longer barrel has more weight one side is fixed by the Trunnion, the rest floats unless interfered with by other structures. As a bullet is fired the projectile goes down the length the barrel will wobble or vibrate. a Shorter barrel has less flex because of less material and as such is stiffer.
A longer barrel has more material to flex. unless that barrel is thickened or reinforced which makes the barrel denser and therefore stiffer.
If you look at what the US tried when it started moving to M16 based DMR's in the 2000's they replaced the stock barrel with a very stiff very thick barrel.
however remember that that is a Heavy barrel and the weapon gets heavier by it.

So a shorter barrel is "More" Accurate yet tends to lack range as the Round fired looses velocity. to make up for this you thicken the barrel to keep the same range yet make a stiffer barrel less prone to vibration, you also free float the barrel to reduce interference by other parts of the weapon. The Problem is of course Weight. The thicker barrel is heavier.
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This is not entirely accurate. A longer barrel will definitely provide increased accuracy at longer range by virtue of imparting greater velocity, which means the distance at which the bullet starts slowing down to transonic speeds is greater than with a shorter barrel. Transonic speeds is where a bullet will start to encounter turbulence resulting in severe yaw- and pitch-inducing forces which will then cause them to start tumbling, resulting in accuracy going to pot. A .338LM or .50BMG round may be able to gain a couple hundred extra meters of stability at long range with a longer barrel.
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
Iron Man said:
This is not entirely accurate. A longer barrel will definitely provide increased accuracy at longer range by virtue of imparting greater velocity, which means the distance at which the bullet starts slowing down to transonic speeds is greater than with a shorter barrel. Transonic speeds is where a bullet will start to encounter turbulence resulting in severe yaw- and pitch-inducing forces which will then cause them to start tumbling, resulting in accuracy going to pot. A .338LM or .50BMG round may be able to gain a couple hundred extra meters of stability at long range with a longer barrel.
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The problem is that the longer barrel's greater movement means that upon leaving the barrel the projectile has a higher potential of being off intended target. the higher velocity then really doesn't matter because where it is pointing is in accurate and as the round looses energy it's going to impact what it's pointing at and not what it was aimed at. Reread this.
A longer barrel has more material to flex. unless that barrel is thickened or reinforced which makes the barrel denser and therefore stiffer.
If you look at what the US tried when it started moving to M16 based DMR's in the 2000's they replaced the stock barrel with a very stiff very thick barrel.
however remember that that is a Heavy barrel and the weapon gets heavier by it.

So a shorter barrel is "More" Accurate yet tends to lack range as the Round fired looses velocity. to make up for this you thicken the barrel to keep the same range yet make a stiffer barrel less prone to vibration, you also free float the barrel to reduce interference by other parts of the weapon. The Problem is of course Weight. The thicker barrel is heavier.
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For weapons like the .338LM or .50bmg you are already dealing with a substantially heavier barrel then that of a infantry service rifle. .338LM rifles are Sniper rifles, .50BMG is used for either Heavy Machine guns or Anti material rifles because of the pressures of the rounds and there intended functions both are far thicker barrels.
 
MwRYum

MwRYum

Major
TerraN_EmpirE said:
It's basically commercial Multicam no if ends or buts. US Military Multicam designated as OCP has a slightly darker color way because of changes in the dyes to make it more effective in the NIR.
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Yesterday I went to queue up for this year's PLA HK Garrison open house ticket, and saw the soldiers still wore the Type 07 camo...
 
I

Iron Man

Major
Registered Member
TerraN_EmpirE said:
The problem is that the longer barrel's greater movement means that upon leaving the barrel the projectile has a higher potential of being off intended target. the higher velocity then really doesn't matter because where it is pointing is in accurate and as the round looses energy it's going to impact what it's pointing at and not what it was aimed at. Reread this.

For weapons like the .338LM or .50bmg you are already dealing with a substantially heavier barrel then that of a infantry service rifle. .338LM rifles are Sniper rifles, .50BMG is used for either Heavy Machine guns or Anti material rifles because of the pressures of the rounds and there intended functions both are far thicker barrels.
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I'm not sure you can demonstrate that greater barrel flex with long barrels effectively negates long range accuracy. This is dramatically opposite my own personal experience and the fact that gun and barrel manufacturers routinely offer different barrel lengths for the same caliber/gun combination. If longer barrel lengths give you worse accuracy there would be absolutely no market for longer barrel options.
 
plawolf

plawolf

Lieutenant General
As with all things related to design, it’s all down to a balance between multiple factors and requirements, with the laws of diminishing returns coming into play.

There was a famous experiment where someone made a bent barrel, that was nevertheless able to shoot accurately, proving you only need the last few inches of the barrel to be true to shoot straight with it.

Usually people want longer barrels for more powder burn, so they get more FPS. That translates to less time to target, resulting in less bullet drop and external influences, like wind, you need to take into account.

Barrel oscillation is a known problem, which is why gunmarkers typically compensate by making a barrel heavier the longer it gets (they could alternatively use better materials to keep weight down, but that carries a monetary cost).

You also need to consider that what is acceptable oscillation for a bolt action sniper rifle with a free floating barrel may well not be for an automatic military weapon without the free float barrel.

In terms of delays to subsonic, for a 50bmg, the bullet will only drop below the sound barrier after 2.6k yards per this calculation. So is it really worth the costs to add a longer (and heavier barrel) for the sake of maybe pushing that back by a few hundred yards more?

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Also, I would not take the line of reasoning that ‘because people buy it it must work’ as all that reliable, as people buy some pretty stupid stuff to bling out their guns a lot of the time.

What some shooters want for fringe needs (like competition shooting, or tacticool) is not necessarily a good reason for general military issue.
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
It's a matter of what you are trying to do with the weapon. If you are just going into a normal range day or most competitive shooting or even combat then a slightly larger group is a non issue. If you are trying to milk the rifle of every possible degree of accuracy then it becomes an issue. Which is why rifles built as DMRs and long range sniping favor heavy profile long barrels. To get the best they can of velocity well countering harmonics.
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
plawolf said:
There was a famous experiment where someone made a bent barrel, that was nevertheless able to shoot accurately, proving you only need the last few inches of the barrel to be true to shoot straight with it.
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World war 2 German army the STG44 Kummlauf device was the extreme. However the curve and device destabilized the bullet and limited the range but since it was intended as a firing port gun that actually worked well. They also found that the sudden change in barrel twist didn't change the bullet that much.
 
Equation

Equation

Lieutenant General
TerraN_EmpirE said:
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Now apply that same physics of the curved barrel onto say an aircraft getting off from a carrier sky jump. One can't just apply or add more speed and speed such as a strap rocket (or the like) onto any jet plane going towards a curvature off the sky jump of a carrier. It would do damaged to the aircraft landing gear itself.
 
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