The Small Arms Thread, Part 8: 2018; ICSR to be replaced by US Army with interim 15mm Revolver Cannon.

[Legiondude]

48 minutes ago, Walter_Sobchak said:

 

Those tactics look a bit Napoleonic to me.  Grouped a bit tightly for modern warfare perhaps?

Maybe they rely on the Warhammer 40k Accuracy Principle? Can't miss a target if the air is completely saturated in bullets

[Walter_Sobchak]

4 minutes ago, Legiondude said:

Maybe they rely on the Warhammer 40k Accuracy Principle? Can't miss a target if the air is completely saturated in bullets

I'm sure it will work great for them as long as nobody shoots back.  

[Toxn]

2 hours ago, Legiondude said:

Maybe they rely on the Warhammer 40k Accuracy Principle? Can't miss a target if the air is completely saturated in bullets

40K has been described as a universe where optometrists and firearms instructors don't exist - you can literally run unarmoured infantry into range of a gunline and have most of them make it to target.

 

Being able to consistently point the barrel of the gun away from yourself qualifies you as a marksman in IG.

[Collimatrix]

5 hours ago, Walter_Sobchak said:

Is this the place to post old articles about heavy machine guns?  I hope so, cause here you go. When this article was published in 1973, the M2 Ma Deuce had already been in service for 40 years.  It's pretty amazing that its still around 43 years after that.    

 

I giggled a bit when I got to the part about how the M85 is a considerable improvement over the M2.

[Ramlaen]

Has there been a study on how well brass, steel or polymer cases pull heat out of a gun?

[Sturgeon]

1 minute ago, Ramlaen said:

Has there been a study on how well brass, steel or polymer cases pull heat out of a gun?

 

I think so. I'll have to look it up in my files.

[Collimatrix]

2 hours ago, Ramlaen said:

Has there been a study on how well brass, steel or polymer cases pull heat out of a gun?

 

I know at one point that the polymer-cased people were saying that less heat left the gun in a polymer case, and that this was a good thing.  Because the polymer they were using was much less conductive than brass or steel, it insulated the firing chamber.  This meant that less of the heat was ending up in the firing chamber in the first place, which slightly improved sustained fire capability.  Also, because less heat was being lost simply heating up the firing chamber, slightly more of the energy produced was available to propel the bullet, which gave a small but measurable improvement in muzzle velocity.

It should be noted that this company's plastic-cased ammunition did not work worth a damn.  But what they were saying was theoretically sound.

[Ramlaen]

22 minutes ago, Collimatrix said:

 

I know at one point that the polymer-cased people were saying that less heat left the gun in a polymer case, and that this was a good thing.  Because the polymer they were using was much less conductive than brass or steel, it insulated the firing chamber.  This meant that less of the heat was ending up in the firing chamber in the first place, which slightly improved sustained fire capability.  Also, because less heat was being lost simply heating up the firing chamber, slightly more of the energy produced was available to propel the bullet, which gave a small but measurable improvement in muzzle velocity.

It should be noted that this company's plastic-cased ammunition did not work worth a damn.  But what they were saying was theoretically sound.

 

That's what I was curious about with the push for polymer cased ammunition.

[EnsignExpendable]

I am just a Mauser C96, don't mind me

 

Surprise! Is actually 6.5x50-mm

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[Bronezhilet]

[LoooSeR]

VSS in Syria

 

[LoooSeR]

G28, Mali

[Ramlaen]

With M855A1/M80A1 style ammunition, does the slug really need to be copper? I would think the production costs would be a lot lower by making it out of steel.

[Sturgeon]

29 minutes ago, Ramlaen said:

With M855A1/M80A1 style ammunition, does the slug really need to be copper? I would think the production costs would be a lot lower by making it out of steel.

 

The slug is copper for added mass (copper is denser than steel). You could make it from steel, and in fact they did create prototypes with monolithic steel cores (two bullets on the right):

 

 

 

These projectiles had to be substantially longer than their copper-cored counterparts, resulting in reduced propellant capacity. Also, their full length hardened cores further reduced barrel life vs. M855 and the copper cored design. The "two wound track" characteristic of the separate cores was also considered desirable.

I will say, as I have some experience with projectile design at this point, that creating a bullet with good characteristics - especially long range characteristics - that is low density is pretty tough. A difference of 7.85 g/cm^3 vs. 8.94 g/cm^3 might not sound like much, but it is actually significant. And, at the end of the day, M855A1 still uses less copper than, say, 6.8 SPC would.

[Ramlaen]

I had assumed it would require a longer bullet but had not considered the reduced propellant capacity.

 

I had also assumed the two cores were meant to ensure the jacket fragmented early/reliably.

[Sturgeon]

5 minutes ago, Ramlaen said:

I had assumed it would require a longer bullet but had not considered the reduced propellant capacity.

 

I had also assumed the two cores were meant to ensure the jacket fragmented early/reliably.

 

They may have something to do with it, but I believe the real mechanism is the thin jacket with several compromised areas, and the gap between the front of the jacket and the exposed penetrator where hydraulic forces can act.

Notably, M855A1 does not actually need to yaw to fragment, unlike earlier projectiles. This, in addition to it needing less energy to fragment in the first place.

[Meplat]

On 9/1/2017 at 6:32 AM, Collimatrix said:

 

I giggled a bit when I got to the part about how the M85 is a considerable improvement over the M2.

Having seen the innards of the M85...

 

yeah, I'd rather deal with the ANM3 and all it's issues.

 

 

[Collimatrix]

Better steels for small-arms barrels!

 

This looks like another example of small arms technology slowly catching up to tank technology.  Or, alternatively, small arms technology slowly catching up to itself in the 1950s.

Steel with hyper-clean microstructure has been used in tank guns for decades now, as well as in tank suspension elements and possibly tank armor (what tank armor is actually made out of being super seekrit).  Also, the Carpenter 158 used in mil-spec AR-15 bolts is a VIM/VAR steel with similarly extremely clean microstructure.

 

Generally speaking, the structural properties of steel are a tradeoff.  Changing the steel's grain structure in such a way that increases hardness, for example, will also reduce the steel's toughness.  Processes like VIM/VAR and ESR remove minute quantities of contaminants like phosphorus and sulfur.  This allows properties like hardness, toughness and fatigue life all to be improved simultaneously.  At least, if you have a expert metallurgist on staff and all the right equipment to do the heat treating precisely enough.

Obviously, like anything this good, all of these steel refining processes are costly.

[LoooSeR]

Prototype of dual-feed MG is developed in Molot.

Quote

.... differs from most modern analogues by the principle of automatic operation -recoil of the barrel. As far as the chosen scheme is operable, time will tell if it work well, and for now the machine gun without the protective-decorative coating and with temporary elements of confinement is going through a series of factory tests.

 

[LoooSeR]

Worst Korea

 

 

[Belesarius]

 

Polish .50 cal 4 barrelled Gatling.

 

[LoooSeR]

AS Val and AS Val

[LoooSeR]

On 07.09.2017 at 4:38 PM, LoooSeR said:

Worst Korea

 

 

 

[LoooSeR]

Max Popenker with RPK-16 (short barrel installed)

 

[Collimatrix]

German troops around a Goliath.  Soldier in the foreground is armed with a rare G41(M).