US MK II Practice vs M21 Practice

[Eodtek]

Reading through numerous threads and posts in the forum it has always been an issue as to the difference between the MK II Practice and the M21 Practice grenades.

My belief (somewhat mistaken) was that it was nothing more than a difference of the bodies to include their composition and frag pattern. Prompted by a post and a request from a member I started digging through the OCM reports a little bit more and found a very interesting fact.

The Grenade Hand Practice (what we know as the MK II Practice) requested to be eliminated on February 27, 1941. The minutes of the meeting are below:

ELIMINATION OF GRENADE,HAND,PRACTICE AND GRENADE,HAND,DUMMY
AND SUBSTITUTION OF GRENADE,HAND,TRAINING.

1. REFERENCES
None

2. DISCUSSION:
a. There are existing requirements shown on Group S, Page 6 of
the Ordnance Book of Standards for a Grenade, Hand Practice and a Grenade, Hand Dummy, the former requiring a grenade body with firing mechanism and a small charge of black powder and the latter being improvised at the present time by use of grenade bodies without the firing mechanism and the practice charge. During the World War period, however, a regular dummy grenade, Hand Grenade, Mark 1, Drawing 82-1-7, of the same size and weight as the service grenade, was utilized. This type is now classified as limited standard. Training requirements are set up by Army Regulation 775-10 for the practice types.

b. The Training Grenade which requires standard type firing mechanisms and black powder charges, costs approximately the same as the regular service type (approximately $1.30) whereas the Dummy Grenade would not cost in excess of fifteen or twenty cents and can be recovered and re-used. It has been ascertained by telephone with the Office of the Chief of Infantry that the practice type is not necessary and that training requirements will be met by a dummy type having the same size, weight and contour as the service high explosive type.

3. RECOMMENDATIONS
The subcommittee recommends that steps be taken to cancel the requirement for a Practice Grenade with explosive charge that Grenade, Hand, Practice Mark II be transferred to limited standard that Grenade. Hand, Dummy, Mark I, Drawing 821-7, be transferred from limited standard to standard.

This action was approved at the following meeting on March 20, 1941 by A.P. Sullivan, Adjuant General.

Understand that this was prior to the war and we were in a cost cutting phase so it probably made sense. Since we have seen photos of shipping containers marked Grenade, hand, Practice M21 dated 1944 we can safely assume that the M21 became the new statndard designation sometime between 1941 and 1944. I'm digging through what I have to try and find that date now.

 

[Grenademan2005]

But, what I understand here is that they wanted to change the dummy grenades for a fully functional grenades, I mean, from grenades in pic one to grenades in pic two. Im right?

 

[sgtlynn]

Hi

Nope, other way round, from the functional practice grenades to the simpler and cheaper throwing dummy.

 

[Eodtek]

Correct. They made the grenades in pic 2 obsolete and used the grenades in pic 1 as the new standard for training.

 

[Kilroy was Here]

Reading through numerous threads and posts in the forum it has always been an issue as to the difference between the MK II Practice and the M21 Practice grenades.

My belief (somewhat mistaken) was that it was nothing more than a difference of the bodies to include their composition and frag pattern. Prompted by a post and a request from a member I started digging through the OCM reports a little bit more and found a very interesting fact.

The Grenade Hand Practice (what we know as the MK II Practice) requested to be eliminated on February 27, 1941. The minutes of the meeting are below:



This action was approved at the following meeting on March 20, 1941 by A.P. Sullivan, Adjuant General.

Understand that this was prior to the war and we were in a cost cutting phase so it probably made sense. Since we have seen photos of shipping containers marked Grenade, hand, Practice M21 dated 1944 we can safely assume that the M21 became the new statndard designation sometime between 1941 and 1944. I'm digging through what I have to try and find that date now.

Hi Eodtek, OK, so will this be the official MkII vs M21 thread now? :nerd:
It will be good to have all this M21 info in one thread. I also have seen and read all the many threads on WW2 practice grenades.

Thanks for posting this minutes report, very interesting. Your right, this was before we were at war in Dec. 1941, and this minutes report is more concerned the cost issue. I would agree you could assume that sometime after this Feb. 1941 report and 5-24-1944, which is earliest date on the 3 shipping cans seen for far, they would have started using the nomenclature "1 Practice Hand Grenade M21".

OK, So then, until you can hopefully find documents with dates of actual adoption of the M21, then by using my two '44 date M21's and cans, and the third 1944 dated M21 can serving as the "basis", then "theoretically" "any" WW2 blue trainer you see, whether it's a threaded filler hole body, or a grenade body that had the threads reamed out, with just a hole, "could or would" actually be called an M21 by at least 5-24-44, and I think even earlier, 1943, and maybe even 1942.

So my thinking says the only way to know what blue trainer grenade anyone has, is to have the orig. shipping container that came with the grenade to see what the nomenclature on the can is, MkII or M21.

This puts a whole "new twist" on all the WW2 era blue trainers out there that most people have been calling MkII practice grenades.
No body really knows what blue WW2 trainer they have now as far as I see it.

Would you maybe agree with this?

Are there anymore photos anyone has with other WWII dated M21 cans? maybe there will be some earlier dates than 5-24-44 on them! :nerd:

 

[Grenademan2005]

Correct. They made the grenades in pic 2 obsolete and used the grenades in pic 1 as the new standard for training.

Does this means that US Soldiers at War used the dummy bodies for training instead of the functional ones?

 

[Kilroy was Here]

Does this means that US Soldiers at War used the dummy bodies for training instead of the functional ones?

I don't think so Miguel, when Dec 7th 41 and Pearl Harbor happened, and we were "soldiers at war" I think things changed again, and we went back to using fuzed "real" trainers again. But were they supposed to be called MkII practice or M21 practice grenades?

I think maybe these are the documents, and minutes reports that Eodtek is searching for?

Please correct me if I'm mistaken Eodtek (Mike?)

I think I read or heard somewhere it was sometime in 1943 they "adopted" the M21.

It would have been interesting to see the M21 what grenade body was in the third shipping can that Frank showed.

As it stands now, what I have thought to be untrue, is untrue.
And that's that the M21's were a specifically designed grenade body, with different shape, and different frag pattern, different materials etc, etc.

This may be true for post war M21 grenades, but it appears it's not the case for WW2 era M21's. I wish more WW2 examples could be seen to be sure about this.

 

[Kilroy was Here]

Reading through numerous threads and posts in the forum it has always been an issue as to the difference between the MK II Practice and the M21 Practice grenades.

My belief (somewhat mistaken) was that it was nothing more than a difference of the bodies to include their composition and frag pattern. Prompted by a post and a request from a member I started digging through the OCM reports a little bit more and found a very interesting fact.

The Grenade Hand Practice (what we know as the MK II Practice) requested to be eliminated on February 27, 1941. The minutes of the meeting are below:
This action was approved at the following meeting on March 20, 1941 by A.P. Sullivan, Adjuant General.

Understand that this was prior to the war and we were in a cost cutting phase so it probably made sense. Since we have seen photos of shipping containers marked Grenade, hand, Practice M21 dated 1944 we can safely assume that the M21 became the new statndard designation sometime between 1941 and 1944. I'm digging through what I have to try and find that date now.

Hi Eodtek (Frank?) Have you been able to find and dig through what you have, and maybe find more out about this issue? I know it has been a busy time of year, so when or if you have the time, any more info or minutes reports on the time of designation of M21's will be appreciated. So far we have my two M21 grenades and their M41 cans dated 8-44 and the third just a can dated 5-44. These are the only WW2 dated ones I know of so far. So we can safely say at least that the M21's were designated as such sometime between 41-44 like you have said above.

Have a good new years soon
Regards, Steve