US Navy 70mm Grenades

[EODGUY]

I post these in this section only because the Navy called them "grenades". During early 1970, the Navy began an in-house program to replace the 40mm grenade on their small patrol boats. They worked on a scaled up version of the 40mm round. The Military Arms Division of Colt also submitted multiple cartridge designs and four weapons candidates to the Navy. All of the ammunition was 70mm in diameter. There was a caseless hi-lo pressure system, a caseless mono-pressure system and a cased hi-lo pressure system. One of the cased versions is the upper grenade in photo 1. It is 10.5" long with a 2.5" long tapered case. The mono-pressure caseless system was truely a unique design. The propellant chamber was attached to the base of the projectile and crimped shut. When fired the crimped chamber opened. The length of this version was 7.25" and it weighed 4.3 pounds. It carried 4 pounds of explosives. An example is the lower grenade in photo 1. Photo 2 shows the crimped base of the grenade. The program died a quiet death and no prodcution was undertaken on any of the designs.

[summitair]

I post these in this section only because the Navy called them "grenades". During early 1970, the Navy began an in-house program to replace the 40mm grenade on their small patrol boats. They worked on a scaled up version of the 40mm round. The Military Arms Division of Colt also submitted multiple cartridge designs and four weapons candidates to the Navy. All of the ammunition was 70mm in diameter. There was a caseless hi-lo pressure system, a caseless mono-pressure system and a cased hi-lo pressure system. One of the cased versions is the upper grenade in photo 1. It is 10.5" long with a 2.5" long tapered case. The mono-pressure caseless system was truely a unique design. The propellant chamber was attached to the base of the projectile and crimped shut. When fired the crimped chamber opened. The length of this version was 7.25" and it weighed 4.3 pounds. It carried 4 pounds of explosives. An example is the lower grenade in photo 1. Photo 2 shows the crimped base of the grenade. The program died a quiet death and no prodcution was undertaken on any of the designs.

Can you supply more information on these grenades, especially the weapon? Did it look like a scaled Mk 19?

[weberoed]

Would this item be part of the 70mm program you were talking about? Though the description says bio/chem others I have talked with said t was designed for smoke and CS. I have not other info onthese rounds, the source they came from has since past away.

MIKE10.JPGMIKE11.JPGMIKE12.JPG

[SLAP_]

Can you supply more information on these grenades, especially the weapon? Did it look like a scaled Mk 19?

There is some information in "The Machine Gun Vol. 5". You can find the book right here. Look at page 515 ff.

[weberoed]

nice find, book book to add to the library. I spend a lot of time on that site, never fails to amaze me what you can find with the right search words

[summitair]

Does anyone out there know if any XM-129's still exist?