Recoiless Rifle

[Hornet33]

Recoilless Rifle Models in the U.S. Military
The recoilless rifle combined a rocket propelled munition with a rifled barrel (unlike the smooth bore bazooka) firing a spin-stabilized round with anti-tank capability. The RR ammunition looks like an artillery round but with "swiss cheese" vent holes in the case allowing escape of the gasses that propel the round. The light recoil made it possible to fire them from the shoulder, a tripod, or smaller vehicles such as a jeep.

There were five major models in the family of Recoilless Rifles fielded by the U.S. Army and Marine Corps:

57mm M18 (WW II & Korea)
75mm M20 (WW II & Korea)
90mm M67 (Vietnam)
105mm M27 (Korea)
106mm M40 (Vietnam)

The M18 and M18A1 recoilless rifle were developed late in World War II for use like a bazooka as an anti-tank or anti-personnel weapon. It was light enough to be fired from the shoulder, although heavier than a bazooka. The M18 takes a 57 mm round effective against 1 inch armor up to a range of 4500 yards (meters) much more range and penetration than the bazooka. The M18 was used by Marines in Okinawa as well as in Korea until replaced by the more effective 3.5 inch M20 bazooka with its HEAT round.

The 75 mm M20 recoilless rifle weighed over 114 pounds and was almost 7 feet long. It was fired from the same tripod used with the M1917A1 .30 machine gun. Its HEAT projectiles were effective against four inches of armor at up to 7000 yards (meters) range, a considerable improvement over the M18 57 mm RR. The M20 was fielded in both the ETO and Pacific Theater during World War II in 1945.

Stands to reason that given that both the M18 and M20 were used in WWII and both were designed to be fired from a machine gun mount, that more than likely they were used on jeeps during the war. Just because no has found a picture you can't rule out that it didn't happen. they were DESIGNED to be fire from jeeps with the appropriate mount and they did see service in both the ETO and PTO.

If a jeep is capable of mounting a .50BMG, that same mount will take a recoiless rifle.

I've also put in a request with the historians at the US Marines Historical Dept for more info regarding these weapons. Who knows what they'll be able to provide.

[BaDkaRmA158Th]

I dont suppose it would have been to much effort for a ARMY engineer to put a bolt thru each bipod leg, and bolt it to the jeeps bed.

Then again, that would be a field modification. And perhaps in that order it was good enough for the army to recognise its need in the war's afterwards.

I still say we just go for a jeep with a bazooka option, it would not be ubber, or fast firing by any means.
But still more likely to have happend in war time than not. "think of a few jeeps transporting some troops to patrol somewhere"

Well, lets just say a few of those troops had a bazooka, and devised a plan to try to flank the tanks, so the driver gunner "bazooka" and reloader "dude in back" desided to launch a small raid on the tanks pining the squad down. "mehheh"

Yeah what'ev'.

:EDIT: wtg hornet, lets hope they can come up with some info, your logic about the mounts, gives me hope.

[ECHO44]

this seems kinda off topic but at the ski resort i go to they use a variety of WWII cannons and explosives for blasting snowy cliffs and one of the weapons is a WWII era recoiless rifle mounted on a tripod
but what does that have to do with AH, sorry

[Warspawn]

I would say there were more Jeep mounted recoiless rifles then there were Osty's and Wirbelwinds, eh?  Probably combined!

[Hornet33]

As a result of rapid advances in armor technology during WWII, infantry units and other lightly armed units were extremely vulnerable to armor attack. This spawned a demand for a weapon light enough to be carried by infantry units but powerful enough to be effective against armor at medium ranges. In 1943 the Ordnance Department Small Arms Division began development of the recoilless rifle. In 1944, the first pilot models of the 75MM recoilless rifle were being tested. In March of 1945, full production began and guns were delivered to the European as well as the Pacific theatre. The advantage of recoilless guns lies in their light weight and relatively high performance. Their light weight characteristic descends from the absence of a recoil when the weapon is fired. By design, the breach expels propellant gasses rearward thereby balancing the forces caused by the projectile accelerating out of the gun tube. This eliminates the need for heavy gun mounts which are a significant part of the weight of a typical artillery piece. A jeep or weapons carrier can easily carry the M20 recoilless rife using the standard M1917A1 .30 caliber machine gun tripod mount. See U.S. Infantry Weapons of WWII by Bruce Canfield for more detailed information on recoilless guns.




                       ADDITIONAL TECHNICAL DATA  75 MM RECOILLESS RIFLE, M20

                       Length..................6 ft. 10 in.
                       Weight..................114.5 lbs. 
                       Rifling.................Unifo rm, right hand, 1 turn in 25
                       Breech..................Inter rupted screw
                       Range...................7000 yards (HEAT round)
                       Muzzle Velocity.........1000 ft./sec. (HEAT round)
                       Projectile Weight.......3.19 lbs. (HEAT, shaped charge)
                       Armor penetration.......4 inches

[snowey]

They had them in late WWII, most were shoulder mounted due to lack of recoil and some were on tripods, in my opinion they go on the jeep only though.

the 75mm one was used by hand but the larger ones were ether used on jeeps or tripods

[Hornet33]

Oh and if not a recoiless rifle how about putting the 37mm anti tank gun from the PT boats on the Jeep?


Soldiers of the U.S. 3rd Infantry (the "Old Guard") are shown on maneuvers in the summer of 1942 as part of the defense of St Johns, Newfoundland. The Jeep is mounted with a small-caliber cannon and a Browning M1917A1 machine gun.

[Masherbrum]

Oh and if not a recoiless rifle how about putting the 37mm anti tank gun from the PT boats on the Jeep?

(Image removed from quote.)
Soldiers of the U.S. 3rd Infantry (the "Old Guard") are shown on maneuvers in the summer of 1942 as part of the defense of St Johns, Newfoundland. The Jeep is mounted with a small-caliber cannon and a Browning M1917A1 machine gun.

Now THAT would be better.   

Recoiless Rifle mounted Jeeps were NOT Common in WWII.   

[trigger2]

Now THAT would be better.   

Recoiless Rifle mounted Jeeps were NOT Common in WWII.   

Eh Iunno, I'd say that as field modifications, they would be. Think of it this way, you have a 75mm recoiless rifle on a tripod, but you can't get in range of the tanks without getting blasted, and you're pinned down, what do you do?
Shouldn't take long to go, get me an engineer, have him bolt this SOB to the jeep, get a couple of volunteers to get it in range. Would they be standard issue? Probably not. Field modification, most deffinitly.

[BaDkaRmA158Th]

Problem is, while the weapons may be capable of being mounted, if it was not made and shiped that way "and used by units" we will never see it in aces high.
You would be better off asking for some form of desert rat jeep, or some other form, i do not think we will see a recoiless anti tank jeep any time soon, but only HTC and time will tell.

[Hornet33]

Eh Iunno, I'd say that as field modifications, they would be. Think of it this way, you have a 75mm recoiless rifle on a tripod, but you can't get in range of the tanks without getting blasted, and you're pinned down, what do you do?
Shouldn't take long to go, get me an engineer, have him bolt this SOB to the jeep, get a couple of volunteers to get it in range. Would they be standard issue? Probably not. Field modification, most deffinitly.

Actually it wasn't a field mod. The M20 75mm recoiless rifle was designed from the start to use the same mount as the .30 cal machine gun, and the .30 cal was the most common machine gun mounted on jeeps. Now if you think about it if you were a soilder and had a 114lb weapon at you disposal and you had the option of A. carry the thing or B, toss it on a mount in a jeep, what would you do?  Also the jeep NEVER came standard from the factory with a weapons mount of any sort. The mounts were ordered and installed by the receiving units for whatever purposes the units needed of them. The mounts were standard issue, the rifle was standard issue, the jeeps were standard issue. NO modifications needed to mount the thing on a jeep only the guy humping the thing to pull a couple of pins and toss it up there. If someones going to tell me that an American soilder was to stupid to figure that one out and not do it, well you've never been a soilder.

[Hornet33]

Problem is, while the weapons may be capable of being mounted, if it was not made and shiped that way "and used by units" we will never see it in aces high.
You would be better off asking for some form of desert rat jeep, or some other form, i do not think we will see a recoiless anti tank jeep any time soon, but only HTC and time will tell.

Actually the weapon was made and shipped that way. It was designed to use the .30 machine gun mount. Granted there was never a unit that was solely equiped with recoiless rifles mounted on their jeeps, but there were never units that were solely equiped with .50BMG's on their jeeps either. The jeep was designed as a multi purpose vehichle and was capable of mounting many different types of weapons. Your suggesting a desert rat type of jeep is no more out of the ball park than asking for a recoiless rifle. Well actually it is more crazy seeing as how those jeeps used by the Desert Rats were highly modified in the field to take twin .30's front and back. Those mounts had to be custom made for those jeeps and only a small handfull were ever set up that way.

The recoiless rifle was a standard weapons system, using a standard mount, on a standard jeep. Every single part needed to mount the thing was standard issue and designed to work together from the factory, same as the .50BMG mount was a standard OPTION for a jeep and we have that. No modifications needed. All you need is a supply Sgt to order from stock, one jeep, one M1917A1 machine gun mount with jeep mounting kit, one M20 recoiless rifle with ammo and about ten minutes to bolt the mount into the jeep and away you go, and the mount will also take the .30 cal machine gun and only take a couple of seconds to swap out the weapons because it only uses 2 pins to hold both of them in place.

This idea has merrit, and that's why I'm backing it up. No one can say it was a field mod. It was designed from the start to do this using mounts that were already in use. EVERY single thing I've read about the M20 talks about it being mounted on a jeep or other light vehicle using a standard .30 mount. Just because there are no pictures of it doesn't mean it wasn't done.

[TEXAS20]

http://en.wikipedia.org/wiki/AMCA_Troupes_Aer%C3%B3l_Port%C3%A9es_Mle._56


I want this      We can ride around smoking cigarettes and drinking wine!  In french accent "Ahhhh HaaHaa....I kill your tiger wit my scooter rifle"

[BaDkaRmA158Th]

Awesome hornet. 


I hope we get this some day.

[E25280]

This idea has merrit, and that's why I'm backing it up. No one can say it was a field mod. It was designed from the start to do this using mounts that were already in use. EVERY single thing I've read about the M20 talks about it being mounted on a jeep or other light vehicle using a standard .30 mount. Just because there are no pictures of it doesn't mean it wasn't done.

"A jeep or weapons carrier can easily carry the M20 recoilless rife using the standard M1917A1 .30 caliber machine gun tripod mount." (emphasis mine).

I see it saying it was meant to be used on a standard .30cal MG tripod mount, not vehicle mount.  Small difference, but an important one.  It was easily carried by a jeep or weapons carrier, not mounted on one.  Again, small but very important difference.  Everything points to it being a weapon designed to be portaged into the field and set up on the ground as any other standard infantry support weapon.

The 75mm versions were shipped to both ETO and PTO according to what was posted earlier (I had always read only PTO service), but the more significant action was on Okinawa in the Pacific after the European War was already over.  Since there were not significant Japanese armor formations, the proposed scenario of mounting one hastily on a jeep to meet the oncoming enemy armor column is far fetched to put it mildly.

So, we are back to burden of proof.  All the photo evidence presented and the snippets I read in my previous look into this topic all suggest mounting the M18 on a jeep occurred after the war was over.  We can suppose it happened all we want . . . without proof, it is still just supposition.

Still looking for the smoking gun - er - RCL.