40mm Beehive round

[Rockwolf66]

The Beehive round is an interesting round as it is marginally more effective than a 40mm buckshot round.

http://www.ballisticsbytheinch.com/22.html

As for lethality there is a report out of the Balkans conflicts of a Croat point-man who used a suppressed American 180 SMG. The guy would encounter Serbs and let off a burst of 20 or so rounds usually killing the enemy point element before they could raise an alarm.

With a beehive round the bullets would be deflected by just about anything. leading to 18 random trajectories. it might not hit anything but it might make someone duck.

[swaghauler]

A couple of useful links.

https://www.globalsecurity.org/military/systems/munitions/m576.htm

http://inetres.com/gp/military/infantry/grenade/40mm_ammo.html

Also worth noting the wealth of adaptors/sleeves available allowing use of full sized 12 gauge ammo (and others) which mitigate the high pressure problem.

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Thanks for the links Leg but they use the older outdated information. I really haven't found a source that can confirm the existence of the 00 Loading (if one exists). The M576 contains plate #4 Buckshot because you CANNOT fit 20 00 pellets into a 12 gauge hull (15 to 18 will fit into a 12 Gauge 3.5" Magnum hull) and only 18 will fit into a 10 Gauge hull. I think I would use one of those cool "inserts" designed to fire 12 Gauge Shells in my 40mm (given the choice). They are also available for Flare Guns/Launchers and are well-proven technology.

[StainlessSteelCynic]

Thanks for the links Leg but they use the older outdated information. I really haven't found a source that can confirm the existence of the 00 Loading (if one exists). The M576 contains plate #4 Buckshot because you CANNOT fit 20 00 pellets into a 12 gauge hull (15 to 18 will fit into a 12 Gauge 3.5" Magnum hull) and only 18 will fit into a 10 Gauge hull. I think I would use one of those cool "inserts" designed to fire 12 Gauge Shells in my 40mm (given the choice). They are also available for Flare Guns/Launchers and are well-proven technology.

I'm a little confused here. Are you saying the M576 does not hold 20 pellets of 00 buck because you can't fit 20 into a shotgun hull

[swaghauler]

I'm a little confused here. Are you saying the M576 does not hold 20 pellets of 00 buck because you can't fit 20 into a shotgun hull

Yes, I am (see below). The original M576 round was made in two configurations. An "E1" version with 20 pellets of #4 Buckshot in a specially vented Sabot designed to release the pellets slowly when fired and an "E2" version which had 27 pellets (also #4 Buckshot) spread across the face of a different Sabot contained in the cartridge. The reason there is even a Sabot to contain the buckshot is due to the pressure needed to launch that payload at 880ft/sec. It comes dangerously close to the roughly 35,000 PSI limit that the original M79 and later M203 were designed to because the M79 and M203 originally had Aluminum barrels and later M203s composite metal barrels (whatever they were...extruded steel maybe). This meant that the M576 grenade has a "liner" inside it (for pressure management) and it then "expels" a Sabot containing the buckshot (to control the rate of pellet expansion). Since the Sabot in the "E1" variant (the "E2" was discontinued during the Vietnam War) clearly protrudes through the nose of the grenade, just by looking at the round it is obvious that the sabot is roughly 12 gauge in diameter. It is also SHORT in length. The M576 is one of the shortest 40mm rounds available. It, therefore, cannot hold 20 pellets of 00 by volume. It also cannot hold them by weight as the round weighs 0.25kg including casing, powder, sabot, and payload. Add to that the fact that the M576 has been in production since the late 60's, and hasn't changed its appearance leads me to believe it is STILL stuffed with #4 Buckshot.

I still hear about this 00 Buck loading and I want to believe that it was made because the M320 can take far more pressure but it would have to have a DIFFERENT designation from the M576 (which contains #4 Buck).

[StainlessSteelCynic]

While not necessarily knowing the specific technical details, I had read some info about its construction and have seen some line drawings of the M576 round.
So I was aware of the "container" (for want of a more appropriate word) for the pellets and the sabot but there's never been any specific detail about the size of that "container".

I had assumed this is what you were talking about but I wanted to be certain. Like you I have checked the details of the M576 in the past but always found conflicting information, some sources state it holds 20 pellets of 00 buck while others say 21 or even 27.
I've also seen images in Jane's Infantry Weapons 1986-87 (page 445) that show two different configurations for the early round, the XM576E1 and the XM576E2. If anything, they serve to confuse the issue because the E1 had the typical "shotgun hull" style container and the air scoops on the sabot while the E2 has a solid sabot with a wide though shallow central cavity apparently filled with 27 pellets.

However I have never seen one of these "in the wild" so all my understanding has come from whatever references I could get (I've managed to get my hands on most 40mm Low Velocity rounds the Aussie Army has used but we never issued the M576 as far as I'm aware).
Now I don't know if you're aware of the following site but it's the one I have usually referenced because the info and images apparently come straight from US Army training manuals.

The only straight-forward info I have on the pellets is from this site and it states that the round holds 20 metal pellets of 24 "g" each
If that's 24 grains then it's half the weight of an average 00 buck as far as I know (roughly 54 grains for 00 shot). If it's grams then it just starts getting silly (24 gram = 370 grain)
So yeah, overall, the whole damned thing leaves me confused!

http://inetres.com/gp/military/infantry/grenade/40mm_ammo.html#M576

P.S. The Jane's Infantry Weapons yearbook is the twelfth edition and ISBN is 0 7106 0829 2 if you want to chase it up

[Legbreaker]

M576 40mm grenade

Straight from the US TM 43-0001-25 Army ammunition Data Sheets found here https://archive.org/details/milmanua...on-data-sheets
At only 115 grams that's a really light round!

[swaghauler]

Straight from the US TM 43-0001-25 Army ammunition Data Sheets found here https://archive.org/details/milmanua...on-data-sheets
At only 115 grams that's a really light round!

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Thanks, Leg. This is EXACTLY what I was looking for to confirm what I discovered initially about the M576. I think that the reason that we don't see a more modern Multiple Projectile Round is that the Army felt it wasn't needed. The M203 was developed so an Infantryman could also have a small arm to protect themselves and that removed the need for the "Buckshot" grenade. Add to that the development of inserts that allow you to fire ANY 12 gauge round and the development of a new 40mm grenade becomes unnecessary. I'm just surprised at how "anemic" the M576 actually is for a 40mm round.

[StainlessSteelCynic]

+1 to what Swaghauler said. That pdf makes things clearer, specifically that it indicates that the payload of the M576, in total, weighs 24 grams (and not each individual pellet as implied by the website I linked to).

[Legbreaker]

A look at the "key to abbreviations and symbols" for the document confirms "g" is grams and not grains.
Looking at the cut away diagram it looks like it could be reloadable too with the right equipment and supplies. Not something you're going to be doing in the field, but pop out and replace the old primer, throw in some new propellant and cap it off with something to replace the copper disk and you're good to slot in replacement projectile assembly.
Not much more complex than reloading small arms ammo.

[swaghauler]

A look at the "key to abbreviations and symbols" for the document confirms "g" is grams and not grains.
Looking at the cut away diagram it looks like it could be reloadable too with the right equipment and supplies. Not something you're going to be doing in the field, but pop out and replace the old primer, throw in some new propellant and cap it off with something to replace the copper disk and you're good to slot in replacement projectile assembly.
Not much more complex than reloading small arms ammo.

I wish the Army would quit mixing units of measure. They use Meters for range and Pounds for weight. They use inches in mechanics and Millimeters in calibers. Just pick one and stick with it!

[Legbreaker]

Us Australians don't have that problem. Like many nations we switched to the much more logical metric system many decades ago leaving just the US wallowing stubbornly in the past.