EwingGreg said:

the old 50 caliber multiple projectile round from Vietnam for Riverine units would probably be better than any "Cannister round" in a .50.

The Army seems to agree; they are playing around with bringing Duplex / Multiplex rounds back for .50 BMG. 

https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/armament/ParisiSmallArms.pdf

https://www.thefirearmblog.com/blog/2018/06/15/what-is-old-is-new-again-ardec-developing-duplex-ammunition/

ARDEC have developed a .50 calibre full-bore duplex round, the XM1175 ‘Interceptor’, this round was designed to be used in all existing M2 heavy machine guns. This means the new ammunition could be used in vehicle mounted M2s or in perimeter defence, in theory any M2, deployed on land, sea or air, could utilise the round.

One of the advantages of the new round is that it can be employed in situations where collateral damage is an issue. The lower mass and the nature of the XM1175’s aeroballistics means that the round will decelerate more rapidly and cause less damage to objects it hits, creating what ARDEC describe as a Smaller Surface Danger Zone (SDZ), giving troops more engagement opportunities in closer quarters.

Parisi explained that “while the technology we have developed is caliber-agnostic, most of our work has been in caliber .50 due to widespread use of the M2 machine gun and the suitability of the two systems for the given mission set.” ARDEC hope the XM1175 will see service in the near future, but in the meantime they are continuing development of small caliber multiplex technology.

I wonder if it will function in a gau-19?   If there is ever a situation where truly Massive amounts of projectiles are needed...    mini Phalanx?

Does the 50 really create a large danger space for troops.....this would make a strong case for a 357 cheytac or 338

Salvo sounds simple enough till you do the  propulsion around the corner and fire trough 3 barrels 

smg762 said:

Does the 50 really create a large danger space for troops.....this would make a strong case for a 357 cheytac or 338

Only if you're going to load the 357 or 338 with ultra-lightweight, low-BC bullets that lose velocity very quickly.

smg762 said:

Does the 50 really create a large danger space for troops.....

It's more a matter of that it creates a large danger space for anything in the general vicinity.  In the heat of the moment, it can be easy to forget that that .50 round that I just shot doesn't magically disappear once it hits (or misses) the target, or immediately slows to a safe velocity after it skips off a street or a body of water.  That's a big, heavy, angry bullet that's still going someplace, and whatever is at that place when it eventually arrives isn't going to be happy about it.

Of course, this is not a new problem.  20 years ago, when we were concerned about the collateral damage caused by errant .50 fire, we simply used something smaller rather than trying to spin up a whole new line of gimped ammunition, but whatevs.  Modern problems require modern solutions and all that, and figuring out ways to make legacy products work for new (and not so new, in this case) problems makes the MIC a sad panda.

And when one panda sues another panda...

Does anyone know how 14.5mm B32 API stacks up to the .50bmg Raufos round in terms of penetration? 

The 14.5 has 2x the energy, but is a steel core API, whereas the .50 Raufos is Tungsten + HEI. 

And are there any modern 14.5mm Raufos equivalent loads?

I ask because these 14.5mm rifles are ~2x the size  of a .50bmg rifle. So I'm wondering whether the 'juice is worth the squeeze' in terms of effectiveness, or if these 14.5mm rifles are strictly of interest as a way to make use of current stockpiles of 14.5mm ammo. 

14.5 in foreground, .50 bmg behind, to give sense of scale for rifles by Truvelo:

If the 50 has 12000lbs energy in full length barrels, im guessig it only has 8000 in those 30inchers?

gatnerd said:

Does anyone know how 14.5mm B32 API stacks up to the .50bmg Raufos round in terms of penetration?

The 12.7x108 mm API B-32 (~52 mm long steel core) is nearly delivering identical AP capability as the 12.7x99 mm APEI NM140.

The 12.7x99 mm PPI (~54 mm long steel core) is mid-way between the NM140 and the NM173 / NM185.

The velocity to defeat 50% of the time a 21 mm RHA plate is around:

• 670 m/s for the 12.7 mm B-32,
• 660 m/s for the 12.7 mm NM140,
• 595 m/s for the 12.7 mm PPI,
• 545 m/s for the 12.7 mm NM173 / NM185. 

The 14.5x114 mm API B-32 is using a 63.3 mm long, high hardness, steel core, the capability is much better than the NM173 (if the gun barrel is long enough).