Indirect fire minimum range

[Zparkz]

FF&S v1 do not mention minimum fire range for indirect fire weapons as mortars. Does anyone have any good ideas how to calculate those?

And at what angle would such fire have to made at?

 

[far-trader]

I think I just took the calculated range to be the minimum. If I recall correctly. Not sure where I got the idea, might have just made it up on the fly.

Fire at 45 degrees will give you the longest range, 90degrees would drop it right back on you (discounting windage) and 0 degrees is direct fire (more or less).

I'm not sure what limits to the angle of fire there would be. It would depend in part what kind of round you were firing, and the intended target. Offhand I'd say anything between 15 degrees and 75 degrees "feels" right.

 

[Timerover51]

Another thread resurrection. The following is taken from Lt. Col. John George's book, Shots Fired in Anger, which can be found on archive.org. Lt. Col. George served on Guadalcanal and then with Merrill's Marauders in Burma. He was also one of the finest shots in the Army and knows about the weapons he is speaking off.

“Actually, the emergency range of any Infantry mortar has no inward limitation. By devising various means of shifting the barrel upward, such as raising the bipod legs, or changing the resting angle of the baseplate, and by providing a means of bracing the barrel in an exaggerated, nearly-vertical position, the bursts can be moved inward until their explosions begin to endanger the crew. Ordnance experts would no doubt condemn this practice as unsafe, but on many occasions the poor doughboy longs yearningly for the comparatively slight dangers occasioned by close-hitting shells —especially when at the moment he may be in a much greater danger because of a half-dozen grenade pelting Japs.”

In addition to this, a mortar may fire at an angle of as much as 85 degree, meaning nearly vertical. As it uses a primer and ignition cartridge, as well as a varying number of propellant charges, the range could be varied almost indefinitely. If fired with just the primer and ignition cartridge, with all of the propellant bags stripped off, ranges could be very short without resorting to propping the bipod legs up higher to get a greater angle of elevation. This would be valid for your typical infantry mortars of between 50 millimeter to 81 millimeter.

The Japanese grenade discharger, often called the "knee mortar", could also be used for direct fire as well as indirect fire, making it quite a multipurpose weapon. The later version fired a rifled shell with an impact fuze as well as time-fuzed grenade. Why someone has not picked up on this idea, I have no understanding.

 

[Condottiere]

Bazookas, rocket propelled, and grenade launchers?

 

[BackworldTraveller]

I've also heard of mortar rounds being used as grenades.

I understand that it is neither safe nor recommended.

 

[whartung]

I've also heard of mortar rounds being used as grenades.

I understand that it is neither safe nor recommended.

They showed that in Saving Private Ryan.

 

[Timerover51]

I've also heard of mortar rounds being used as grenades.

I understand that it is neither safe nor recommended.

I shows up in several personal accounts from World War 2. One use was by a guy named Charles Kelly who won the Medal of Honor in Italy on September13th and 14th of 1943. The following is his Medal of Honor citation. Emphasis added by me.

For conspicuous gallantry and intrepidity at risk of life above and beyond the call of duty. On 13 September 1943, near Altavilla, Italy, Cpl. Kelly voluntarily joined a patrol which located and neutralized enemy machine gun positions. After this hazardous duty he volunteered to establish contact with a battalion of U.S. infantry which was believed to be located on Hill 315, a mile distant. He traveled over a route commanded by enemy observation and under sniper, mortar, and artillery fire; and later he returned with the correct information that the enemy occupied Hill 315 in organized positions. Immediately thereafter Cpl. Kelly, again a volunteer patrol member, assisted materially in the destruction of 2 enemy machinegun nests under conditions requiring great skill and courage. Having effectively fired his weapon until all the ammunition was exhausted, he secured permission to obtain more at an ammunition dump. Arriving at the dump, which was located near a storehouse on the extreme flank of his regiment's position, Cpl. Kelly found that the Germans were attacking ferociously at this point. He obtained his ammunition and was given the mission of protecting the rear of the storehouse. He held his position throughout the night. The following morning the enemy attack was resumed. Cpl. Kelly took a position at an open window of the storehouse. One machine gunner had been killed at this position and several other soldiers wounded. Cpl. Kelly delivered continuous aimed and effective fire upon the enemy with his automatic rifle until the weapon locked from overheating. Finding another automatic rifle, he again directed effective fire upon the enemy until this weapon also locked. At this critical point, with the enemy threatening to overrun the position, Cpl. Kelly picked up 60mm. mortar shells, pulled the safety pins, and used the shells as grenades, killing at least 5 of the enemy. When it became imperative that the house be evacuated, Cpl. Kelly, despite his sergeant's injunctions, volunteered to hold the position until the remainder of the detachment could withdraw. As the detachment moved out, Cpl. Kelly was observed deliberately loading and firing a rocket launcher from the window. He was successful in covering the withdrawal of the unit, and later in joining his own organization. Cpl. Kelly's fighting determination and intrepidity in battle exemplify the highest traditions of the U.S. Armed Forces.

Firing a bazooka inside of a building was also not recommended.

 

[Condottiere]

 

[whartung]

Thats a PIAT. It's spring loaded. They didn't have a good reputation as I understand it.

(I looked it up, it actually has a charge that launches the warhead, but the firing pin spring is supposed to be a real bear to cock.)

 

[Timerover51]

Thats a PIAT. It's spring loaded. They didn't have a good reputation as I understand it.

(I looked it up, it actually has a charge that launches the warhead, but the firing pin spring is supposed to be a real bear to cock.)

You lay on your back and use both of your legs to push the cocking mechanism. It cocks itself then after every shot. The projectile is fairly heavy and it apparently kicks like a mule. It was quite capable of knocking out a tank, if you could load it first.

 

[TheDark]

The PIAT launcher is heavy (15 kilograms), but the projectile is fairly light (1.1 kilograms). It has about the same range and penetration as an M9 bazooka (~150 yards direct fire and 4 inches of RHA at a right angle), which weighs 6.9 kilograms for the launcher (7.2 for the M9A1 with a different sight) and 1.6 kilograms for the projectile. The Panzerschreck, for comparison, was 11 kilograms with the blast shield (9.25 without) and fired a 3.3 kilogram projectile with about the same effective range, but closer to 9 inches of penetration against armor.

All of them can fire farther, but they'd be indirect fire without adequate sights or range tables.

 

[Enoki]

Thats a PIAT. It's spring loaded. They didn't have a good reputation as I understand it.

(I looked it up, it actually has a charge that launches the warhead, but the firing pin spring is supposed to be a real bear to cock.)

The PIAT training manual--yes, I have one-- actually has a part on how to perform indirect fire with it...