ARES Advanced Individual Combat Weapon for the Advanced Combat Rifle competition

[Pyrrhic victory]

-Rising Chamber
-Cased telescoped ammunition
-Withdrawn after Phase I of the ACR competition
-Related to Future Assault Rifle Concept (FARC)?

 

[prolific1]

Re: ARES Advanced Individual Combat Weapon fro the Advanced Combat Rifle competition

Pretty cool.

 

[lantinian]

Re: ARES Advanced Individual Combat Weapon for the Advanced Combat Rifle competi

When way this project developed?

 

[Abraham Gubler]

Great pictures Phyrrihc. ARES under the technical leadership of Eugene Stoner (designer of the M16) and funded by DARPA developed Case Telescoped Ammunition (CTA) technology in the 1970s. They realised the first CTA weapons in 5mm (this rifle), 12.7mm (TARG), 35mm (TALON) and 75mm (XM274). They also designed CTA solutions for everything from 5.56mm to 90mm.

 

[Lauge]

Never heard of this one before (and I'm supposed to be a small-arms guy - I hate that )

Polymer case-telescoped ammunition could be making a come-back with the US Lightweight Small Arms Technologies programme:

http://www.dtic.mil/ndia/2005smallarms/wednesday/spiegel.pdf

Regards & all,

Thomas L. Nielsen
Luxembourg

 

[Rickshaw]

Interesting design. How were the rounds moved from the drum magazine to the chamber?

That magazine would cause problems nowadays. The location versus the widespread use of armour would make it impossible to aim effectively with it.

 

[Abraham Gubler]

Interesting design. How were the rounds moved from the drum magazine to the chamber?

It’s pretty clearly shown in the action diagrams above. The round at the top feed position of the magazine is moved forward by a protrusion of the bolt into the chamber pushing out the empty casing forward. When the trigger is pulled the chamber moves upwards freeing the under spring pressure bolt which moves forward so the firing pin can engage the round.

That magazine would cause problems nowadays. The location versus the widespread use of armour would make it impossible to aim effectively with it.

No it wouldn’t. The greater width of the drum magazine is still about three inches forward of the butt. This would still allow for a traditional angled away from the line of fire stance without coming into contact with the chest or vest. Soldiers are now trained to have a stance at a right angle to the line of fire so as to expose the hard face of the body armour to enemy fire. The benefit of this is that even through your profile may be bigger the armour can stop the bullet rather than it entering under your left arm and into the chest cavity.

 

[vajt]

Very interesting design. Looks better than AAI's current LSAT design. Go to the bottom of page 2 on the pdf to see the latest cased-telescoped LSAT prototype.

http://www.aaicorp.com/pdfs/lsatps09-09-08.pdf

I hope AAI will take advantage of the fact that a cased-telescoped (and even more a caseless) round is lighter and smaller to increase the rounds carried in a clip or drum.

-----JT-----

 

[Abraham Gubler]

The LSAT is designed to be a replacement for the M249 light machinegun (aka Minimi) and is therefore a very different weapon to the ARES AIWS. The LSAT trial methodology is that the new weapon and ammunition needs to be able to meet every M249 performance specification except to be as light as possible. So this means belt feed, changeable barrel, etc. They are claiming a 45% weight reduction with polymer CTA ammunition to date. The magazine feed rifle variant is just a minimal change of the primary LMG. At this level of development (TRL 5) they can't be expected to customise this weapon for the infantry combat weapon role.

 

[Nik]

Thanks for the links ! The rotary loader gave me an idea for something a little larger...

 

[Colonial-Marine]

Great pictures Phyrrihc. ARES under the technical leadership of Eugene Stoner (designer of the M16) and funded by DARPA developed Case Telescoped Ammunition (CTA) technology in the 1970s. They realised the first CTA weapons in 5mm (this rifle), 12.7mm (TARG), 35mm (TALON) and 75mm (XM274). They also designed CTA solutions for everything from 5.56mm to 90mm.

Was the 75mm XM274 the same gun planned for use on the AAI RDF light tank?

 

[Abraham Gubler]

Was the 75mm XM274 the same gun planned for use on the AAI RDF light tank?

It was the same gun but it was actually used in a range of US Army 1970s and 80s tank demonstrators and prototypes.

 

[amsci99]

My apologises for replying to such a dated discussion but I thought this to be the appropriate forum to seek the wisdom of Abraham on whether flechettes were considered for CTA rounds? I also read somewhere that flechettes for some advanced rifle program was supposed to manufactured by growing them from seed crystals using a process not unlike that employed for turbine blades.

 

[Abraham Gubler]

I don’t know about wisdom, just memory. The Steyr entry in the US Army’s 1980s ACR competition fired a flechette round through CTA ammunition. This round had a lot of problems with robustness of the case and stability of the flechette (sabot release, etc) so very much underperformed. On paper it was pretty lethal with a muzzle velocity of 1,450 ms that was retained through much of the flight. From memory it was still travelling at around 1,000 ms at 1km range. The use of CTA ammunition also enabled it to have an annular primer and a fixed, right angle firing pin. The action of the weapon was extremely simple and likely to be very robust in use.

The flechette used in the Steyr ACR was not a micro flechette it had a diameter of about 1-1.5mm so it would be quite easy to make in conventional castings or machining. Even made from such methods it would be highly effective at body armour penetration thanks to its velocity and sectional density. I guess single crystal super alloys could be a material for producing very strong small arms flechettes. But then you would have an infantry small arm able to penetrate tank armour!

 

[Lauge]

The AAI entry for phase II of the ACR competition also fired a flechette type round, this one using a standard 5.56x45mm cartridge case.

According to http://www.globalsecurity.org/military/systems/ground/acr.htm, the data for the flechette itself was size 1.5x42 mm, mass 0.66 grams and muzzle velocity 1400 m/s.

Regards & all,

Thomas L. Nielsen
Luxembourg

 

[amsci99]

Abraham,

Thank you again. Btw, could flechettes be made through the die-stamping process?

 

[Abraham Gubler]

The AAI entry for phase II of the ACR competition also fired a flechette type round, this one using a standard 5.56x45mm cartridge case.

According to http://www.globalsecurity.org/military/systems/ground/acr.htm, the data for the flechette itself was size 1.5x42 mm, mass 0.66 grams and muzzle velocity 1400 m/s.

Its interesting looking at the combat accuracy results of the ACR competition. The two flechette firing weapons achieved about 80% at 50m and then dropped down past 20% for the 150-300m range targets. The AAI weapon had about a 5-10% advantage at 50m over the Steyr weapon but dropped down behind it at range. The flechettes were effective at short range (50m) and then lost their stability after this providing very poor at range effects when their very short time of flights and very low loss of heights were on paper supposed to provide them with an advantage.

The difference between the Steyr and AAI weapons at close range can be attributed to the complete rigging of the ACR competition by the US Army. All of the US weapons (M16 baseline, AAI flechette and Colt duplex) had the advantage of ACOG or ELCAN ~x4 magnified combat optics compared to the ~x1 optics of the European weapons (H&K G11 and Steyr). This provides them with a significant improvement in accuracy caused by the sight not the weapon.

The clear winner of the ACR was the G11 which outshoot the M16 and the Colt duplex despite having a far inferior combat optic. That a rifle can outshoot another out to 300m with a x4 deficit in magnification of the sight is a clear indication that it is far superior. Of course since the test had been rigged and such a *minor* detail was overlooked in the result summary it appeared that no new weapon provided a clear advantage over the M16 so no new weapon was acquired.

 

[Abraham Gubler]

Btw, could flechettes be made through the die-stamping process?

Probably not as the flechette (French: little dart) needs to have fins for yaw for in flight stability. Flechettes for artillery munitions are actually produced from steel wire in a similar manner to nails.

 

[Pyrrhic victory]

Hughes Lockless weapons + ammunition

 

[Pyrrhic victory]

Patents for telescoped casing and rising chamber weapon

http://www.google.com/patents/about?id=F4ouAAAAEBAJ
http://www.google.com/patents/about?id=Tu80AAAAEBAJ
http://www.google.com/patents/about?id=8-E4AAAAEBAJ
http://www.google.com/patents/about?id=uOM0AAAAEBAJ

 

[Abraham Gubler]

Hughes Lockless weapons + ammunition

Another great post, thanks a lot!

 

[John21]

I would just like to post some videos of the various competitors for the ACR rifle:
http://www.militaryphotos.net/forums/showthread.php?179077-Advanced-Combat-Rifle-videos
Just go there and you will have them.

 

[Abraham Gubler]

Its interesting looking at the combat accuracy results of the ACR competition. The two flechette firing weapons achieved about 80% at 50m and then dropped down past 20% for the 150-300m range targets. The AAI weapon had about a 5-10% advantage at 50m over the Steyr weapon but dropped down behind it at range. The flechettes were effective at short range (50m) and then lost their stability after this providing very poor at range effects when their very short time of flights and very low loss of heights were on paper supposed to provide them with an advantage.

The difference between the Steyr and AAI weapons at close range can be attributed to the complete rigging of the ACR competition by the US Army. All of the US weapons (M16 baseline, AAI flechette and Colt duplex) had the advantage of ACOG or ELCAN ~x4 magnified combat optics compared to the ~x1 optics of the European weapons (H&K G11 and Steyr). This provides them with a significant improvement in accuracy caused by the sight not the weapon.

The clear winner of the ACR was the G11 which outshoot the M16 and the Colt duplex despite having a far inferior combat optic. That a rifle can outshoot another out to 300m with a x4 deficit in magnification of the sight is a clear indication that it is far superior. Of course since the test had been rigged and such a *minor* detail was overlooked in the result summary it appeared that no new weapon provided a clear advantage over the M16 so no new weapon was acquired.

A forum member has asked about my source for the ACR hit probability and I promised to upload it when I could. It is from two Ph tables as quoted in Wolfgang Seel’s “Die G11 Story: Die Entwicklungsgeschichte Einer High-tech Waffe” and supported by commentary in the text.

As you can see from the attached tables despite having a far inferior combat optic the G11’s three round burst function enabled it to match and/or exceed the Ph of the M16A2 and Colt ACR using x3-4 magnifying optics. What it could achieved if the sighting issue was a level playing field remains to be seen. If the ACR trials had been conducted in such a fair manner maybe the G11 would be in service today with the US Army…

Hit probability as a function of range of the ACR candidates in Phase I (Picture 12) and Phase II(Picture 13) trials. Source: US Army Material Systems Analysis Activity: Independent Evaluation Report No. 5-91 of the Advanced Combat Rifle, August 1991

 

[Abraham Gubler]

Attached is the original H&K G11 brochure from back when it was a going thing. Also an image explaining the very important controlled dispersion of its unique salvo burst fire.

 

[sferrin]

This might be of interest to you guys:

http://www.quarry.nildram.co.uk/Assault.htm

ASSAULT RIFLES AND THEIR AMMUNITION:

HISTORY AND PROSPECTS

 

[RanulfC]

-Rising Chamber
-Cased telescoped ammunition
-Withdrawn after Phase I of the ACR competition
-Related to Future Assault Rifle Concept (FARC)?

I'm probably the only one who did, but I still have to ask....

Did anyone else look at "drum-jpg" and think "NERF gun!"????

Randy

 

[F119]

Here is an excerpt from the ACR test summary: