autogun

Military Guns and Ammunition

Hosted by autogun

This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons.

  • 3216
    MEMBERS
  • 182825
    MESSAGES
  • 8
    POSTS TODAY

Discussions

heavy machine guns   General Military Discussion

Started 20-Mar by smg762; 4415 views.
smg762

From: smg762

20-Mar

i recall FN developed a prototype heavy MG in the 80's, which had a 15mm round, and plastic driving bands to lower barrel wear. the idea was to bring performance closer to a 25mm, and be useful against APCs....more so than the .50.  it was called the BRG 15.

i wondered about a scratch build design where sabots are used to completely eliminate barrel heating. in theory you could last thousands of rounds without a barrel change.  it would be used in tandem with polymer cases, and the sabot/bullet would be entierly hidden in the case. Like the steyr ACR ammo.

also the sabot gives a free energy boost, allowing a lighter round and smaller gun.

for instance you could have a .338 lapua bullet, fired at double the normal energies.  (8000ft lbs instead of 4500) yet the overall system weight would be barely higher than an 7.62 GPMG.

  Bullet is 8.6mm but sabot is 15mm.

any thoughts? especially in regards to the possiblities of heat elimination..

and on a very different note, what about anti APC usage. would a burst of 762 tungsten at 8000ft lbs be best, or on the opposite end, a single 13mm HE round? are .50 HE rounds at all useful against material?

  • Edited 20 March 2021 8:28  by  smg762
In reply toRe: msg 1
EmericD

From: EmericD

20-Mar

smg762 said:

i wondered about a scratch build design where sabots are used to completely eliminate barrel heating.

What make you think that the use of sabots will eliminate barrel heating?

Are you planning to use cold gas to push the sabot?

In reply toRe: msg 2
ZailC

From: ZailC

20-Mar

15mm is on the small side for engaging APCs, especially those armed with 25 or 30mm guns. In general, for medium caliber cannon, a discarding-sabot round with a tungsten penetrator (spin-stabilized or fin-stabilized) delivers more kinetic energy on target than explosives that can be packaged in a full caliber round up through 40mm. For armor penetration the advantage of kinetic energy penetrators over explosives seems to extend up through 120-130 mm direct-fire cannon. 

In reply toRe: msg 1
stancrist

From: stancrist

20-Mar

smg762 said:

are .50 HE rounds at all useful against material?

.50 raufoss - YouTube

In reply toRe: msg 1
tidusyuki

From: tidusyuki

21-Mar

I'm always had a thirst of learning how dual fed machineguns worked. But there's so little info about them. Another example would be the Dover Devil and it's derivative, the CIS/STK 50

proditto

From: proditto

22-Mar

The CIS 50 is not in any way a "derivative" of the `Dover Devil.  CIS had no information on how the DD worked at the time of the start of the .50 project.

The dual feed is very simple using a rotor. One feed is under the rotor and the other above. The main feed was below and the over the top for SLAP etc. The change over is remove the belt and insert the other under or over the rotor.

roguetechie

From: roguetechie

22-Mar

So on the dover devil there is a simple lever switch which clutches one rotary drive and activates the other. 

I'll see if I can find a picture that shows it.

roguetechie

From: roguetechie

22-Mar

Ok so here's the relevant picture and description from the patent. Unfortunately I don't have high resolution enough pictures to show you the lever on the actual gun but here's what I have.

I'll try to find better pictures where the damn lever is visible.

roguetechie

From: roguetechie

22-Mar

You are unfortunately correct about the CIS 50.

In reality I highly suspect that it takes inspiration instead from the dover devil's progenitors the xm235 & xm248 which it is pretty substantially based off of.

It's still neat but it's no dover devil that's for sure.

As an example the dover devil was qualified for use off the standard m60 tripod which implies substantially less recoil than the current m2 while being a non trivial amount lighter and cheaper.

We definitely missed a pretty serious trick by not adopting the DD.

It's aradcom competitor otoh... Whew we definitely dodged that bullet.

The more I delve into the dover devil design the more I find to appreciate about it.

As an example, the way it's controls feed units and housings are set up would make it trivially easy and quite amenable to set up as an RWS gun or coax or etc. It's already designed from the outset to accept actuators and a capability to do some fun and interesting ammunition routing for armored housing use.

proditto

From: proditto

23-Mar

The CIS design team had no knowledge of any data on the configuration of the DD or its origins.The use of twin guide rods seems to the reason that the designs are confused. The CIS gun used them for very specific reasons. The CIS gun had many fewer parts than the M2. Interestingly the CIS gun was regularly fired from the M60 tripod as this was a secondary requirement. A neat adapter allowed it to be fired from a variety of different mount. It was also used in a turret with the CIS grenade launcher. 

TOP