Grenade Luncher ranges?

[weswood]

Once again, it's easy for an average shooter to hit even at longer ranges with a grenade launcher.

Indirect fire is according to all the rule sets is not easy to hit a target.

Indirect fire rules should only apply when the sights cannot be used as intended - ie plunging fire with the weapon held at greater than 45 degrees or if the target is not directly observed. ALL fire using the sights is direct.

I think I see where I've been confused. The weapon can fire direct fire but also indirect fire mode for plunging fire. Somehow I had the idea that it had to be indirect fire to get the round to travel that far as with a bow & arrow.

Dohhhh!

[Legbreaker]

It is actually a "semi indirect" sort of situation at longer ranges, with the weapon having to be held at a fairly steep angle. For practical and game purposes though, if the shooter can see the target, they can use direct fire - unless they decide to fire indirect for some reason (such as wanting a delay between firing and detonation as described previously).

By the same token a weapon crew firing a 105mm artillery piece has the option of using direct fire if the gunner can see the target (point or area). With an artillery piece however, at longer ranges it may actually be more accurate to fire indirect due to limitations in the sights themselves (and the fact that it's hard to see a target 5 miles away with the naked eye).

Some weapons of course can only fire indirect - mortars being the prime example.

[cavtroop]

I found this on Wikipedia (http://en.wikipedia.org/wiki/M79_grenade_launcher).

"Some US Navy SEALs and Army Special Forces in Iraq have been seen using the M79 in recent years, most likely due to its greater accuracy and range compared to the M203 (350m effective versus 150 m effective on the M203)."

Another reason why Wikipedia should never be used as source material.

I've personally hit targets at 400m with an M203. 400m is the advertised max effective range for that weapon system.

[perardua]

I was told by some American military personnel that the M79 is preferred for certain tasks as it's break-open loading mechanism meant it was possible to load it with longer specialty rounds which the M203 loading mechanism doesn't allow. This was in a conversation about the merits of my UGL, which is based on a German design and swings out to the side to load, again allowing for easier loading of longer rounds (if the MoD would ever come through on their promises to buy any). British UGL's also have the ladder sight attached directly to the side of the weapon, whereas I believe M203s have to be zeroed to a removeable sight attached to the M4

I also heard that the M203 replacement will be a derivation of the same UGL system as the Germans and British use, possibly for these very reasons.

[Legbreaker]

I was told by some American military personnel that the M79 is preferred for certain tasks as it's break-open loading mechanism meant it was possible to load it with longer specialty rounds which the M203 loading mechanism doesn't allow.

Correct.
The M79 does have a safety though which isn't exactly in the best position - new users can rip the webbing between thumb and forefinger when firing if they're not careful. Not exactly a big thing, but worth considering from an roleplaying point.

[atiff]

The 40mm low pressure grenades are also low muzzle velocity (about 76m/s for most rounds if I remember my training right) .....

Assuming 76 m/s is correct, physics dictates that (no friction, no wind, flat terrain) the maximum range (45 degree shot) is approx. 590m, with an 11-second flight time.

Brought to you by your friendly physics major

[Fusilier]

Some weapons of course can only fire indirect - mortars being the prime example.

No. Mortars can fire direct as well. All they need to do is be able to see the target. There are specific firing drills for this.

[pmulcahy11b]

No. Mortars can fire direct as well. All they need to do is be able to see the target. There are specific firing drills for this.

It's called a direct lay, but it's not really direct fire. You're still lobbing the round up and over to the target. You're just putting the target directly in the sights and squaring up the bubbles, or guestimating for a hand-fired 60mm.

[perardua]

Yep, it's pretty much the only way the 51mm and it's 60mm replacement is supposed to be fired.

[Fusilier]

It's called a direct lay, but it's not really direct fire. You're still lobbing the round up and over to the target. You're just putting the target directly in the sights and squaring up the bubbles, or guestimating for a hand-fired 60mm.

Yes, but as long as that up and over round is going to a target that you can see it is still direct fire.

[StainlessSteelCynic]

I was told by some American military personnel that the M79 is preferred for certain tasks as it's break-open loading mechanism meant it was possible to load it with longer specialty rounds which the M203 loading mechanism doesn't allow. This was in a conversation about the merits of my UGL, which is based on a German design and swings out to the side to load, again allowing for easier loading of longer rounds (if the MoD would ever come through on their promises to buy any). British UGL's also have the ladder sight attached directly to the side of the weapon, whereas I believe M203s have to be zeroed to a removeable sight attached to the M4

The M203PI was developed to address the issue of only being able to load certain rounds (specifically, the Illum round was too long for the earlier variant so the PI version is able to move the tube further forward to allow the Illum rounds to be loaded). However, I don't know if they are issued widely enough for all units with M203 launchers to benefit.

[StainlessSteelCynic]

I think I see where I've been confused. The weapon can fire direct fire but also indirect fire mode for plunging fire. Somehow I had the idea that it had to be indirect fire to get the round to travel that far as with a bow & arrow.

Dohhhh!

I think I see where that particular confusion has come from - the idea that you would need to elevate the weapon higher for indirect fire than you would if you were engaging a target at closer ranges I think this line of thinking has come about because some of the weapons that are listed in the rules as having indirect fire, typically use a lobbing or plunging trajectory to facilitate indirect fire but it pays to remember that any weapon is capable of indirect fire. Direct and indirect fire are not specifically a function of the range of the weapon nor it's most commonly used trajectory.

As stated before, direct fire is any type of fire where you can personally observe the target - if you can see it, it's direct fire (because you can personally observe the fall of shot and make corrections as needed to hit the target etc. etc.).
It's indirect fire only when the person aiming the weapon cannot personally see the target, that is, they are relying on a grid co-ordinate or on someone else giving target corrections and so on.
For example if you fire your shotgun at a rabbit 50m away, it's direct fire but if the rabbit was in some brush 10m away and you couldn't directly see it, you will fire where you think the rabbit is and even though the trajectory is reasonably flat, this is indirect fire.
If you throw a rock at someone, it's a straight flight path to the target but it's only because you can see the target that this is direct fire. If you tossed that rock over a high wall in the hopes of hitting someone you thought was on the other side, that would be indirect fire because you don't know specifically where the target is.

[Panther Al]

I think I see where that particular confusion has come from - the idea that you would need to elevate the weapon higher for indirect fire than you would if you were engaging a target at closer ranges I think this line of thinking has come about because some of the weapons that are listed in the rules as having indirect fire, typically use a lobbing or plunging trajectory to facilitate indirect fire but it pays to remember that any weapon is capable of indirect fire. Direct and indirect fire are not specifically a function of the range of the weapon nor it's most commonly used trajectory.

Indeed: During the Franco-Prussian war, the french, who was far better armed riflewise than the Prussian Army was at a strong disadvantage because they was trained not to fire directly at the Prussians: Instead, they would form up in mass, and whole companies would fire at once at a designated beaten zone, with the thinking that plunging fire from masses rifles was far more effective than shooting right at the Prussians. Since the Prussian Army was soon taking its holiday in Paris, its safe to assume that wasn't such a hot idea. The British on the other hand, took this idea, and used a different tool: The Vickers. Take a platoon of four HMG's, and aim them all in semi-indirect fire at a selected beaten zone, you get a good effect on the the target, as long as all you are trying to do is prevent someone from moving through that zone. It was used to good effect in the first and second world wars, though less so in the second due to keeping the HMG's supplied with the immense amount of ammo such tactics consumed.

[Legbreaker]

Almost any machinegun that can be tripod mounted can be fired in an indirect role. The M60 for example can fire in the indirect, sustained fire role out to about 3,000 and uses the exact same sighting unit as the 81mm mortar (at least here in Australia anyway). The Support Section of an infantry company 20 years or so ago trained to use machineguns in exactly this manner, in addition to being the AT section armed with M2 Carl Gustavs (carried one or the other depending on the OC's orders).

I would have to say as a rule of thumb, if the weapon barrel is elevated over 45 degrees (aka plunging fire) or the target cannot be directly seen and sights laid on it, Indirect Fire rules should apply.

If the target can be seen and sights laid on it, provided the barrel isn't elevated at 45+ degrees, then direct fire rules should apply.

As has been touched on, there are a number of factors influencing accuracy - wind being one of them. The longer a round is in the air, the more these factors will come into play. Therefore, from a rules perspective, the greater inherent inaccuracy of indirect fire makes perfect sense.

[perardua]

Almost any machinegun that can be tripod mounted can be fired in an indirect role. The M60 for example can fire in the indirect, sustained fire role out to about 3,000 and uses the exact same sighting unit as the 81mm mortar (at least here in Australia anyway).

Likewise for the GPMG in British service when in the sustained fire role, also using the same C2 sight as the 81mm mortar.