US M781 40MM Practice Grenade

[inertordnance]

Attached is a photo of a US M781 manufactured Circa 1983, note the nylon driving band on the projectile. Can anyone advise were this type of driving band fell into the scheme of things in comparison to the current zinc / aluminum manufacture?

Thanks and stay safe,

Frank

 

[EODGUY]

Interesting question that I never thought of before. I have lined up some M781's from my collection starting with one on the left that I cannot ready the date on, but it is marked XM781 so it is early. The next ones are 1980, 1981, 1983, and 2000 respectively. As you can see, my 1983 one has a plastic rotating band, but it is surrounded by metal ones. This makes me wonder two things. First, since the lot number, etc. is on the M212 cartridge case, is that the date of the case and not the complete round. Or, is there a "mod" to the projectile specs that allows the use of either type of rotating band so the contractor can choose either depending on cost and/or production capabilities. According to my documentation I think the round was fielded in 1976 and of course, it had a metal rotating band. The only other projectiles I know of with plastic rotating bands are the M1001 Canister and the XM1006 less than lethal, but there may well be others I can't think of at the moment. Hopefully someone has some firm information.

 

[grog18b]

Hey Frank, not sure if I spoke to you, or Ken about these. I had a few a while back, and heard that they were discontinued for use because of the plastic fouling in the barrels being hard to remove. I think they might have been a trial projectile that was ultimately rejected, not only because of the fouling, but the plastic being hard to recycle from range scrap. I still have one complete one, and they fired just fine, as far as I'm concerned. I didn't have any trouble with fouling, but I didn't fire a case of them.

GROG

 

[inertordnance]

EODGUY & GROG,

Thanks for checking in! Interesting that I have observed examples of these Style M781's from different sources over the years and they all had M212 Casings marked circa 1983 with varying lot numbers. Sounds like an attempt at a design improvement that was manufactured for a short time and terminated.

Thanks again and stay safe,

Frank