60 мм shoulder-fired mortar T-20 need help

[karlik]

Hi!
I found a picture of USMC 60-mm mortar T-20

looking at his photos and specifications of this weapon
help me please!
thanks in advance!

[Mil-tech Bard]

Is this thing supposed to be recoilless?

[karlik]

I think that is not fully recoilless,read somewhere that after a few rounds from this mortar marines were sent to hospital for treatment.

[Ironmachine]

Hope this helps:

The T20 used a spring recoil mechanism and the barrel can be seen recoiling in the rear housing in the first bit of video. There seems to be some differences in the bipod and mount in all of the various photos but the basic weapon still looks the same. In the disassembly photos below, it's interesting that the launcher seems to have a single monopod spring mount with two feet on a crossbar at the bottom, much like the monopod used with the current 85mm Carl Gustav RR employed by U.S. Special Forces.

According to the R&D Record, one shoulder fired 60mm was observed at a demonstration at Quantico in late 1943. Based on that weapon, Springfield Armory made two of the T20 mortars and submitted them to Aberdeen for further tests. The project was then turned over to the Marine Corps Equipment Board for additional refinements and 100 of the mortars were manufactured for overseas tests. No indication regarding where the additonal 100 were made unfortunately. But I'm pretty sure we're looking at one of those 100 mortars. I don't know of a surviving example but if it's anywhere, it's probably in the vault at Quantico.

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Source: http://www.usmilitariaforum.com/forums/ ... =0&start=0

[karlik]

Ironmachine greatest thanks!!!

[ROLAND1369]

In the text it says the standard round is fired "with the cartridge only". This means that the additional powder increments [u]are not used[/u]. A 60 mm mortar has a base charge which looks like a large shotgunshell. 6 Additional propellant charges called increments, are attached to the fins to achieve the max 1800 yard range, For firing at closer range targets these increments are removed. So if the weapon fires only the base charge and has a recoil system, the recoil should be less than the average WWII AT rifle and thus easily bearable if not comfortable for the firer

[Mil-tech Bard]

Ironmachine greatest thanks!!!

This weapon was used by the USMC's 1st Division at Peleliu because they had so many failures with Bazooka rockets in the mud of Cape Gloucester:


http://www.ibiblio.org/hyperwar/USMC/US ... .html#fn63

The second new weapon was the 60mm shoulder mortar, a standard mortar adapted to a light machine gun mount for direct, flat-trajectory fire against caves and pillbox openings. Some of its parts proved not rugged enough for sustained use and had to be replaced nearly as often as the poor devils who were obliged to fire the contraption from their shoulders. Essentially its functions duplicated those of the bazooka, and its adoption resulted from the frequent failure of bazooka rockets to detonate in the soft mud of Cape Gloucester. However, there proved to be very little soft ground amid the coral of Peleliu and, although the shoulder mortar was used effectively, it came to be considered less practical all around than the weapon it had been designed to replace.63

63. "As presently constructed, they (shoulder mortars) are too heavy and certain parts are too weak. . . . After firing two to four rounds, it is necessary to replace the gunner. Units feel that the shoulder mortar as now constructed is not of sufficient value to include it in the authorized weapons." 1st MarDiv SAR, II, Annex A, 5.

They ditched this kludge by the time of Okinawa.