according to this table...

[gijunkman]

Goo, which M7 launcher do you have? Usually the weight of the grenade pushes the poppet valve open. (so you can fire the rifle with ammo that has a bullet and not have to remove launcher) If the BM59's launcher is 22mm (7/8") and I'll bet it is, yes U.S. rifle grenades will work. Hope this helps.

[Mark in Rochester]

as near as i can tell the 'plunger on the launcher doesn't push the poppet valve on the GCL screw down unless you push it down.
might need a special screw
any inputs?
thx,
goo

It should push it in on assembly with a M7

M7a1, M7a2 and M7a3 launchers have a spring loaded feature that disengages the valve when the projectile leaves

the weight of a mounted projectile should force the launcher assy down thus opening the valve and closing valve after launch

If you have a a1,a3 of a3 be sure the spring on the bracket end is not stuck

also check valve is free to move

HTH

[goo]

the weight of the grenade(dummy, no warhead) does not push the poppet valve open. so it needs to be made heavy enough to open the valve and is not safe to shoot as is, right?
it seems to me they must have launched the training rounds as is. so i'm not sure what they did to close the valve.
what was the spec weight of the real ones?
...thx,
goo
..
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[Dan Shapiro]

I wanna go play at gijunkman's house. Neat 'toys'!

[The Wizard]

Any standard NATO 22 mm Rifle Grenade will fit on a BM 59. There is NO M1 rifle Grenade! There are rifle grenades that are launched from the M1 both rifle and carbine. The most commonly run into rifle grenades are the M29 and M31 practise grenades and sometime the M118 or M118A1

[Bill Ricca]

I want to clarify: The weight of the grenade does not actually push back the launcher. I always called them "recoiling launchers" to distinguish them from the M7, but that is not an accurate description. The launcher acts as a piston and is pushed to the rear by the gas pressure of the Grenade Cartridge.

The loadings from WWII had black powder because Ordnance was afraid they would not get complete ignition without a projectile in the bore. All postwar loadings eliminated the black powder. From a history in progress:

There were constant disagreements inside Frankford Arsenal about the addition of black powder, which was used as a reliable source of ignition. Since the days shortly after WWI ordnance loaded black powder in all similar cartridges with the concern that since there was no projectile like that with conventional ammunition, powder ignition would be incomplete. Today many published references note the addition as a booster. Not so, says Mr. C. Robert Olsen (Bob Olsen), a young engineer at Frankford Arsenal during the war. Bob Olsen, during this wartime work at Frankford Arsenal attempted to get the black powder removed from M3 GC loadings. It wasn't until after the war that ordnance would adopt the results of many of the tests he performed. All the post war loadings of the M3 relied strictly on smokeless powder. The M6, which Mr. Olsen helped develop, never used black powder during its production. The results of testing and his perseverance convinced FA that the black powder requirement could be eliminated; the smokeless powders would get sufficient ignition without it. Sometime after the war FA changed the specifications to reflect the elimination of black powder from the M3 loading.

[goo]

thank you very much,bill. while it might be fun to launch a grenade with my garand. its always good to learn about all the functions. thanks to you, all us novices here are a little more knowledgeable (but still novices!)
...
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[Bill Ricca]

I remember Wizard purchasing a load of M29's from me in either 1989 or 1991, when I first retrieved the load. He is always very knowledgeable and an honest guy.

[The Wizard]

Bill,

You are a gentleman and scholar. Thank you for your kind words.

[goo]

"the weight of a mounted projectile should force the launcher assy down thus opening the valve and closing valve after launch"
...
if i understand bill ricca, the above is not quite correct.
...seems as tough mark in rochester may be in error.
(i think).

seems to me mark should have said,
"...the RECOIL (or gas) of the grenade launch ( not the basic weight of the grenade) forces the launcher assembly down..."
the valve will be closed prior to launch and will only momentarily open DURING firing.
...
Marine one, quantico, 2008,
reunion of my 1967 USMC OCS class...
...
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