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.

I've thought for some time that rifle grenades deserve a closer look. A few years ago, I finished a presentation on grenade launchers (in which I suggested that the advent of advanced sights, air-burst systems and MV rounds seemed likely to result in a specialist grenadier in the section) with this:

Ole 30mm Yugoslav M60 had 70g of Hexolite or similar explosive and all up weight of 480g 

Real use for rifle grenades was if remember correct 150m , beyond that accurate aiming was not great, but of course, if you had side-mounted optics sights or even ballistic computers as some have for Grenade launchers I don't think there would be much difference in range or accuracy.

But on the other hand GM-94 43mm has more HE charge than 30-40mm rifle grenade(although no fragmentation belt)

GM-94 43mm launcher was always fascinating ,' grenade 250g weight is close to 40mm but it has 130+g of explosive(vs cca 30g in 40x46) and with 85m/s muzzle velocity its also  faster , downside is recoil.

YouTube

Russian KBP GM-94 43mm Multi-Role grenade launcher

GM-94 grenade launcher in service Russian counter-terrorism task forces Several VGM93 cartridges are available, as follows: VGM93.100 - Thermobaric (FAE) rou...

And given the multiplying effect of thermobaric it's effective radius is probably still as large as a fragmenting projectile. It's a big and heavy launcher as required by the round, but looks much more practical than revolver launchers which are even larger and heavier. 

autogun said:

This suggests that there might be a case for considering the use of rifle grenades instead. These are less accurate, but typically carry twice the HE load and avoid the need to carry a separate launcher.

I think this idea has a lot of merit in light of emerging optics technology.

The Army is looking to go from IR lasers to IR Laser with integral range finder:

https://www.army-technology.com/news/l3harris-secures-order-for-delivery-of-storm-2-to-us-army/

Meanwhile, Matbock has come up with a simplified grenade launcher sight. The range to target is entered, and then the weapon is simply raised upward. When the right angle for the range is achieved, a light turns green, signifiing for a shooter to fire.

https://taskandpurpose.com/military-tech/grenade-launcher-sight-socom

If the 'grenade launcher angle' feature of the matbock was added to the IR Laser range finder (seems like a pretty simple addition) then every soldier would essentially be equipped with a Grenade FCU for firing rifle grenades, with a minimal increase in bulk vs the current Ir laser sight + range finder.

The only problem I see - possibly insurmountable - is the switch to 100% suppressed use. At a minimum, this would require greatly expanding the diameter of rifle grenades to be able to slip over a suppressor. 

I also imagine firing a RG with a 6.8 would result in pretty insane levels of recoil. Plus whether a bullet catch system could contain 6.8 AP.

gatnerd said:

The only problem I see - possibly insurmountable - is the switch to 100% suppressed use. At a minimum, this would require greatly expanding the diameter of rifle grenades to be able to slip over a suppressor.  I also imagine firing a RG with a 6.8 would result in pretty insane levels of recoil. Plus whether a bullet catch system could contain 6.8 AP.

All good points.

Recoil, in the end, is down to the mass of the RG and if you want less you just need to make them lighter, Old RG were quite heavy as they were initially meant for anti armor the non-overcaliber antipersonnel versions have tiny charge for given weight Only cca 70g of explosive for 500g grenade. The lighter grenade easier the bullet traps job ,There are walkarounds for absorbing the bullet by telescoping the trap and even by telescoping function compressing a secondary propellant that is discharged through the nozzles on the body but i don't think the RG is making comeback ,even tough it would make much more sense wen it comes to rifle launched drones or guided ammo.

The Grenade launcher is simply to entrenched ,and with 203 on the scrapheap the side opening ones can house longer payloads.

Altough when you look at PIKE its basicaly the size of a rifle grenade only constrained to fit the 40m Grenade launcher

This one looks like it uses missile seeker as aiming optic 

Just need more trap material. Or a mag of blanks for grenade launching.

Farmplinker said:

Just need more trap material. Or a mag of blanks for grenade launching.

Or just a "pass-thru" grenade, like the old FN "Bullet Thru(R)" rifle grenade.

Interesting enough, this concept didn't catch up because it was nearly impossible to make a good HEDP.