Red7272 said:

A long time ago some reservists from my old job got to fire 40 rounds at a M113 hulk. It drills a neat 6 mm hole though the armour but behind armour effect seemed pretty minor.

Yes, even with larger shaped charges like the RPG, the behind armor effect is reportedly minor, unless fuel, explosives, or personnel are in the direct path of the jet.

stancrist said:

Yes, even with larger shaped charges like the RPG, the behind armor effect is reportedly minor, unless fuel, explosives, or personnel are in the direct path of the jet.

To be expected. I'm not sure if any other NATO country uses HEAT 40 mm. Certainly the Germans went for a much more effective HE with a superior fuse when they adopted the grenade launcher. 

Blowhard personality aside, here's at least decent footage of HEDP impacts (see around 4:42 and 7:18)

https://youtu.be/oqyLoU_0Av4?t=282

It sucks. At least 40x53 has a beefy enough steel body that it gives you decent fragmentation along with the pencil diameter hole it punches if you really MUST go HEDP, and putting that projectile into a lower pressure / velocity casing has been proposed in the past.

We're not fighting BMPs and even if we were we're equipped for near peer conflicts with enemy armored divisions. We have no shortage of things that can kill armor.   What we really need is a dedicated MV HE round, with a bounding function, plus incorporation of advances in fuze miniaturization since the stone age, then improved fillers, projectile design, and PFF / fragmentation optimization so you can eek every last bit of performance out of the little guy.

It's all been thoroughly studied and would be a pretty straightforward procurement, but it's kind of like hem and hawing over what pistol to buy -- those making these decisions don't think it matters much in the grand scheme of things, the war isn't going to be won or lost over it (though someone's life might, that's outside their scope of consideration).

We're reaching a point now where you can probably come up with a drone that fits in a 40mm grenade pouch that can reach out beyond 1,000m... and even if the tradeoff is a payload more like a 20mm or 25mm projectile, it ain't gonna matter when you deliver it into their lap.  Probably not going to get away with it in a near peer conflict with heavy EW, but for anything less you might as well get into the game because the enemy certainly will.

Refleks said:

We're reaching a point now where you can probably come up with a drone that fits in a 40mm grenade pouch that can reach out beyond 1,000m... and even if the tradeoff is a payload more like a 20mm or 25mm projectile,

https://soldiersystems.net/2019/05/24/sofic-19-defendtex-drone-40/

The round is fired from the launcher in order to get it aloft. To attain flight mode, it deploys four helicopter-style rotors to stabilize, move, and provide lift for loiter.

It offers 12 minutes of flight time and/or 20 minutes of loiter time. Cruising speed is 20 m/s and range at optimum speed is in excess of 10km.

Payloads include camera, anti-armor, fuel-air, HE/frag, diversionary, smoke, counter-UAS,

Red7272 said:

To be expected. I'm not sure if any other NATO country uses HEAT 40 mm. Certainly the Germans went for a much more effective HE with a superior fuse when they adopted the grenade launcher.

France bought 40 mm HEDP grenades to go with the HK269 F launcher... but we are also using rifle grenades (but don't repeat it, it's a secret!)

EmericD said:

France bought 40 mm HEDP grenades to go with the HK269 F launcher... but we are also using rifle grenades (but don't repeat it, it's a secret!)

How is this expected to work out in practice, Emeric? Will some units have the UBGLs and others the RGs? Or will the 40mm eventually take over?

Some nice pics of experimental US grenade rounds in this thread: https://forum.cartridgecollectors.org/t/grenade-launcher-cartridges/41601

All units will have HK269 F (probably one per fireteam) and riflemen without the 40 mm GL could use rifle grenades instead.

So what are y'all doing with rifle grenades? How much performance improvement has been made in the last 2 or 3 decades for rifle grenades?

Farmplinker said:

So what are y'all doing with rifle grenades? How much performance improvement has been made in the last 2 or 3 decades for rifle grenades?

Well, the AP/AV 40 PAB Mle F2 is using a bullet trap, so you launch it with a "live" SS-109 round.

With the FAMAS or the HK416 F there is no need to change the setting of the gas block (no block on the FAMAS, and only one setting on the HK416 F) so after firing the grenade, you just need to press the trigger again to fire "KE rounds".

The MV of the AP/AV 40 is just a handfull of m/s smaller than your typical 40x46 mm LV grenade, so the trajectory is very similar, same for accuracy between 0 and 350 m.

The difference is that the recoil is higher because the grenade weight is 435 g, with two times the casualty radius of the typical 40x46 mm LV, and better AP capability.

Thanks! It's been a while since I read about rifle grenades, so it's nice to be updated.