Hand Grenades

[defiant]

A while back I acquired some (inert) WWII pineapple practice hand grenades. The grenades look like this:

http://img134.imageshack.us/img134/6752/grenade1bg4.jpg

http://img338.imageshack.us/img338/1517/grenade2zo8.jpg

The fuse is a M228 practice grenade fuse. US military grenade fuses operate in the same manner. However there are differences in delay times (from 2-5 seconds), and whether the fuse is an ignitor or a detonator.

When the safety pin is pulled from the grenade, and pressure is released from the “spoon” (i.e. lever or handle) – as would be the case when its thrown. Releasing the spoon allows the striker/firing pin to rotate forward under spring pressure - resulting in the spoon pivoting upwards and two hooks on the spoon releasing themselves from two round protrusions on the fuse.

http://img338.imageshack.us/img338/281/grenade3jk4.jpg

http://img177.imageshack.us/img177/9909/grenade4nx2.jpg

With the spoon removed (and the pin out) the striker releases and the back side of the striker and the spring is visible:

http://img177.imageshack.us/img177/6545/grenade5nt9.jpg

A straight portion of the spring rests on the back of the firing pin. The spring has a second straight portion, not pictured, that is secured behind a ridge on the fuse body.

The next photo in this series is of the striker in the cocked position, whereby the firing pin and the cap are visible. The striker is under spring pressure in this position, and is held back by the pin.

http://img340.imageshack.us/img340/8634/grenade6fk7.jpg

Note that there are two holes going through the fuse body. One is for the safety pin, which secures the spoon handle. The other is a safety for cocking the striker (with a live fuse).

http://img264.imageshack.us/img264/8476/grenade7oy2.jpg

The pin above the cap prevents the striker from coming onto accidental contact with the cap. There’s quite of bit of pressure exerted by the spring on the striker, so pulling the striker back on a live fuse while fumbling with spoons and pins is ill advised. The striker is small, and inadvertently can slip out of fingers prying it back to cock it. Blocking the cap isn’t a frivolous safety measure.

With proper safety precautions cocking the striker is simple. First, stick a cotter pin or stronger pin of appropriate size through one of the holes over the firing cap, and angling the pin downwards through the hole pry up on the striker while sliding the pin into the hole on the opposite side of the fuse. The striker will only be lifted 1/16” or so, and the spring doesn’t exert much pressure with the striker lifted so slightly. So it’s not difficult to do, and if the striker does accidentally slip there isn't enough spring pressure to set off the cap. Once the striker is pried up high enough slide the pin in the opposite hole.

Now the striker can be pulled back with your finger and a second pin inserted through the rear holes in the fuse (as pictured immediately above).

Next secure the hooks of the spoon under the round protrusions on the fuse and, maintaining pressure between the spoon and the grenade, remove the pin that blocks the spoon holes from aligning with the holes on the fuse, line up the holes, re-insert the pin through the spoon/fuse holes to secure, and bend the cotter pins to lock in place. The pin blocking the cap can now be removed.

http://img340.imageshack.us/img340/1918/grenade8dv5.jpg

http://img148.imageshack.us/img148/7389/grenade9xo3.jpg

http://img241.imageshack.us/img241/9783/grenade10ci9.jpg

http://img241.imageshack.us/img241/5563/grenade11kl8.jpg

http://img99.imageshack.us/img99/3193/grenade12gd8.jpg

Inert fuses are legal and available online.

Its probably not legal to load a live cap in them, load the delay portion of the fuse with the appropriate powders, and crimp on a live igniter or detonator. :rolleyes:

http://img99.imageshack.us/img99/4929/usgrenadeinternaldiagrawu4.jpg

[Gothy]

Cool. Thats some nice coverage of the good ol' handgrenade. I would like myself one of those alright. As a display object in the livingroom or similar.

Nice pics aswell

[defiant]

Yeah...

http://img406.imageshack.us/img406/9764/grenadelamphp5.jpg

[Zait]

First post jitters here but I feel comfortable enough responding on this subject.

A while back I acquired some (inert) WWII pineapple practice hand grenades.

I hate to be the bearer of bad news but that isn't a WWII grenade (commonly referred to as the MK II) so I hope you didn't pay more than $5 ea for them. Your pictures show a recast version of the M21 practice grenade. The M21 is cast using a different metal and can be identified by the rounded frag pattern instead of the normal squared edges on a MK II. The one you bought is a recast based on the fact that it doesn't have it's orignal paint and the frag pattern is off. I'd be willing to bet that the grenade also has the letters "RFX" cast into the side. That is from Richmond Foundry who is no longer in business but had sold their molds to someone else. There are also overcasts from China and Korea that are slightly larger and have RFX stamped in them from when they took an M21 and created a new mold using an existing grenade.


The fuse is a M228 practice grenade fuse. US military grenade fuses operate in the same manner. However there are differences in delay times (from 2-5 seconds), and whether the fuse is an ignitor or a detonator.

The fuse you are showing in the grenade is a M213 that is used with the M67 grenade. It is the "live grenade" variant as opposed to the M228 which is the practice grenade variant. The M228 has a blue handle with a brown tip on the spoon. The M213 is solid OD green. Both have the same delay time which by MIL-SPEC is approx. 5 seconds.

The M213 is an explosive detonator while the M228 is an ignitor that contains a black powder charge designed to make smoke and noise for the practice grenade.


Inert fuses are legal and available online.

Its probably not legal to load a live cap in them, load the delay portion of the fuse with the appropriate powders, and crimp on a live igniter or detonator. :rolleyes:

Reloading them is tricky to say the least. I've seen it attempted but never seen it done correctly. The main problem is compressing the delay column to the correct density to keep the fuse from functioning instantaniously.

[defiant]

Good first post Zait.

You're correct about the RFX stamp down the side (its even pictured in one of the photos above). Didn't know that it was a recast from Richmond Foundry though. Thanks.

In any case I paid $4 for it, and it wasn't purchased because I'm a collector that want's the best specimen of a particular model or something along those lines. I'm interested more in how things work and can be manufactured. If someone were to actually manufacture a grenade body for military purposes it would need to be a brittle alloy in order for it to frag effectively.

I didn't know that the RFX grenade bodies are made out of a different alloy. It seems pretty hard/brittle though, but if its less brittle than an original it wouldn't frag as well as an original. It's still fine for concussion fishing though. :p

You're wrong about the fuse though - I substituted a green handle for a blue one (aesthetic reasons) :D, Its a M228, or at least it was represented to me as an M228. Its also likely that less of the fuze would remain if it was a M213...

As you say, the mechanism is the same, but the M228 is loaded with an igniter (and has a blue spoon) whereas the M213 has a detonator (and a green spoon).

Reloading them is tricky to say the least. I've seen it attempted but never seen it done correctly. The main problem is compressing the delay column to the correct density to keep the fuse from functioning instantaniously.

A custom crimping die and a bit of experimentation ought to be able to resolve that sort of problem. Also, sealing the top of the crimp with varnish or epoxy might have added benefit. The sample appears to be done that way - might be to seal out moisture though.

Also, do you know anything about fuzes for rifle launched grenades?

Or the M577 fuze???

http://img142.imageshack.us/img142/3535/m577001gu0.jpg http://img142.imageshack.us/img142/7732/m577002sg5.jpg

[Zait]

Also, do you know anything about fuzes for rifle launched grenades?


Which rifle grenades, the 40mm series? If so then yes as I have a few sitting in my collection.

And yes, I'm also familiar with the M577 MTSQ fuze but I don't recall off hand if I have one sitting around here.

What are you looking for?

[tiac03]

I hate both of you. lol.

All I have in my "collection" If I can call it that is One of the recast grenades (Without striker assembly), An emptied WW2 one (Must have been dug up and then explosives removed and the bottom part of the fuze broken off where the cap would have been. Spring was rotted out and the striker was siezed.) A few empty artillery casings, and a sight from what I think is an artillery piece with NATO markings and made by Filotecnica Salmoiraghi.

If anyone here knows what It is for I'd appreciate knowing also.

Other markings on it are
Sight dial #2 (Mils)
and it has 3 adjustment knobs Two are made the same but one says "MAIN" and the other "Shooting"

Sorry For hijacking the thread, please talk about the Fuzes, I love knowing how different ones work, which is why I think I have such an Unhealthy facination with Mines. (If only I knew where those people that go around to schools lecturing about the evils of mines get theirs, I would love to get a M-16 with M-605 fuze, or an S-mine)


So sorry for my interruption and please continue explaining.

[defiant]

tiac03:

This thread probably deserves to be hijacked - but I'm not familiar with the items your seeking information on. Posting a picture might help. For grenades check out ebay, or in quanity http://www.oldsargesdropzone.com.

Also, fuses are different than fuzes - the latter refers to artilley. Ebay's a source, but there's probably better sources free of bidding madness. For a fuze used just prior to the M557 - the MTSQ-M564 - check out 'http://www.sportsmansguide.com/cb/cb.asp?a=170554'. $20.

Zait:

I don't own 40mm round works but think I know basically how they work - centrifugal force (imparted on the round by barrel grooves) retracts pins that hold the detonator assembly rearward, releasing it forward and allowing the firing pin to reach the cap upon impact - detonating the round. Feel free to correct me if I'm wrong.

In any case, what I'm interested in is the older 22mm rifle grenades. I can't find any information as to whether these devices have safety's built into their detonation system, or how detonation specifically works. Any information you can provide (or anyone can provide) would be appreciated.

Discussion of the M557 fuze is probably out of place here - albeit it is I who digressed. I'll start a new topic for military artillery fuzes when the time is right, starting with a movie that's being sent to me that's supposed to explain artillery fuzes in some detail. As the movie dates back to the 40's, it won't include the M557.

If you want to create the topic, that would be great. My priority right now is breaking in a couple of barrels and dialing in some scopes.

[Zait]

In any case, what I'm interested in is the older 22mm rifle grenades. I can't find any information as to whether these devices have safety's built into their detonation system, or how detonation specifically works. Any information you can provide (or anyone can provide) would be appreciated.



By 22mm I'm guessing you are referring to the older series of grenades that are fired using an adapter and a blank grenade cartridge. If not then a nomenclature would really help.

If so then one of the simplest is the M22:

http://img460.imageshack.us/img460/6578/m22yv0.jpg

It as a free floating firing pin held back by a creep spring. It fires on direct impact and usually does not fire on a glancing blow. Other than the safety clip, there is nothing stopping the grenade from firing if you drop it on the ground. That is why they only use a firing system like this on a pyrotechnic and not an HE filled item.

[defiant]

You understood correctly what I meant by 22mm rifle grenade, and the image you posted was very helpful. What military manual did you get that out of?

Also, so you know, they weren't just for pyrotechnics or signal purposes - there were also HEAT and fragmentation models.

You're right about the 22mm rifle grenades falling out of favor with the advent of underbarrel and devoted 40mm launchers, which had rifled barrels. The rifling causes the artillery round/fuze to spin, imparting centrifugal force on safety pins within the fuze which moved outwards upon firing and unlocked the firing pin (and in still later models the firing pin and explosive train). A US Army film on fuze technology (which explains the basic principles) is available at http://mihd.net/6wtx3o .

Its a bit retro for me to want to know more about the older fuzes, but I don't drop things (often).

[Zait]

You understood correctly what I meant by 22mm rifle grenade, and the image you posted was very helpful. What military manual did you get that out of?

TM 43-0001-29 Grenades


Also, so you know, they weren't just for pyrotechnics or signal purposes - there were also HEAT and fragmentation models.

Yes, I varients of them sitting in boxes in my basement because I haven't build shelves for them yet.


You're right about the 22mm rifle grenades falling out of favor with the advent of underbarrel and devoted 40mm launchers, which had rifled barrels.

That and the fact that a soldier had to remove his live ammunition and replace it with a blank launching cartridge to fire the grenade. Some countries still use barrel adapted rifle grenades but they now use a bullet trap so you can launch them with a ball round.


The rifling causes the artillery round/fuze to spin, imparting centrifugal force on safety pins within the fuze which moved outwards upon firing and unlocked the firing pin (and in still later models the firing pin and explosive train).

For soft launch items like the 40mm that is pretty much dead on. Fuzes for larger projectiles also have an inertia lock on them that is released upon firing and before centrifugal force can work on the fuze.


A US Army film on fuze technology (which explains the basic principles) is available at http://mihd.net/6wtx3o .

That is a pretty good film to get the basics from. Well done on finding it.

If you can find copies of the OCM (Ordnance Committee Meeting) reports you will find some very interesting ideas on ordnance and fuzing.

[defiant]

TM 43-0001-29 Grenades

Just acquired that earlier this month, at which time links were provided: (http://www.ammoinfo.com/downloads/TMs/TM-43-0001-29.pdf at http://www.roguesci.org/theforum/showthread.php?t=5388&page=17). I'm gonna try not to feel too foolish...:rolleyes:

That and the fact that a soldier had to remove his live ammunition and replace it with a blank launching cartridge to fire the grenade. Some countries still use barrel adapted rifle grenades but they now use a bullet trap so you can launch them with a ball round.

As you point out there was more than one rational for swithching over. Fuze safety was one factor, and so were advantages associated with a soldier carrying ball rounds rather than blanks and ball rounds. This rational makes some sense, but carrying a couple of blanks or color coded mags of blanks is far less burdensome than transporting quantities of rifle grenades. Thus this official explanation falls short.

A third rational for swithching over to through fire or ball fire rifle grenades is that a soldier rushed by an enemy would be vulnerable with a grenade loaded on the launcher and a blank chambered. This too makes sense, but a soldier today with an rpg, stinger, or other devoted grenade launcher is equally vulnerable to fragments from their own grenade if rushed by an enemy at close range.

But a grenade was never intended to be a close range weapon, and devoted grenade launchers of various sorts continue to be of value. The Mk19 Automatic Grenade Launcher is one such example...

http://img246.imageshack.us/img246/4640/usmk19mod3automaticgrentj4.png

But despite this firepower the guy with an AR in the background appears to fulfill a protective role at closer ranges. Not that the newer technology isn't awesome.

But despite technological improvements that make predecessor weaponry appear antiquated - a 22mm blank fired rifle grenade is feasible for someone operating on a limitted budget (not empowered to collect taxes), and are comparatively easy to manufacture, concealable, capable of being used with on readily available weapons with little modification, propell grenades further than can be thrown by hand, and can be shaped charged. Although they are obsolete by modern US military standards - its conceivable that there might be circumstances where they'd be useful.

For soft launch items like the 40mm that is pretty much dead on. Fuzes for larger projectiles also have an inertia lock on them that is released upon firing and before centrifugal force can work on the fuze...

Don't know what you mean by "soft launch items" - but even 22mm blank launched rifle grenades need an inertia lock to prevent them firing when launched - which is why early impact detonation rifle grenades used a crushable nose to prevent the pin from firing due to launching inertia.

That is a pretty good film to get the basics from. Well done on finding it.

Purchased, ripped, and uploaded by yours truly for purposes of distant learning and fair use.

Any chance of you uploading OCM (Ordnance Committee Meeting) reports? [No leads on google and it would be appreciated.]

[Zait]

The Mk19 Automatic Grenade Launcher is one such example...

But despite this firepower the guy with an AR in the background appears to fulfill a protective role at closer ranges. Not that the newer technology isn't awesome.

That picture is of soldiers firing on a familiarization or qualification range. If they were in a combat situation the other two wouldn’t be standing there (even though the weapon is classified as “crew served”). The M16 being shown in the background probably isn’t there in a protective role rather it’s there because the troop carrying it is standing there.


Don't know what you mean by "soft launch items" - but even 22mm blank launched rifle grenades need an inertia lock to prevent them firing when launched - which is why early impact detonation rifle grenades used a crushable nose to prevent the pin from firing due to launching inertia.

The launch of a rifle grenade is “soft” compared to the launch of an 81mm mortar. A rifle grenade such as the M22 only has 2 safeties on it. The first is a safety pin and the second is a creep spring. The safety pin keeps the grenade from firing due to an accidental drop while the grenade is off the rifle and the creep spring keeps it from firing while it's in the air.

The setback during launch of the M22 is enough to keep the fuze from firing but not enough to compress a setback spring and setback pin to release a slider as is demonstrated in the M52 projectile fuze. Funny side note is that the M52 needed setback at launch but it was a small enough force that you could remove the safety pin and slam the mortar on the ground tail first and the fuze would arm. There are stories of soldiers who did this and used the 60mm mortars as hand grenades when they were in danger of being over run.


Any chance of you uploading OCM (Ordnance Committee Meeting) reports? [No leads on google and it would be appreciated.]

Sorry but they won’t be uploaded anywhere (the size of the files and the scarcity of the info keeps it from happening) due to a gentlemen’s agreement. Outside of museums there are probably less than 12 copies of the 2 disks that contain the unclassified reports. The only two ways that I know of that people can find and read them (the hardcover reports) is by visiting a military museum that may have them or by visiting the National Archives in DC. They are very accommodating and will do all they can in helping you research something. You can even make copies of most things.

Two books that may help you and can usually be bought on Ebay ,a Antique book store or even Amazon (which is showing both available in used condition) are:

Elements of Ammunition –Maj. Theodore C. Ohart, Published 1946 by John Wiley & Sons, Inc.
Elements of Ordnance – Col. Thomas J. Hayes, Published 1938 by John Wiley & Sons, Inc.

Both were used as textbooks and they have excellent line drawings of early fuzes and detailed descriptions on how they function.

[defiant]

Yeah, its pretty obvious that the photo of the guys with the Mk19 Automatic Grenade Launcher isn't a combat photo. The photo was mostly worked into the post as a joke - but depending on the situation and the manpower available it isn't an altogether bad to have point men with short ranged weapons.

Thanks though for the other info, and particularly the leads to the books and reports - it's very much appreciated.

[sparkchaser]

Speaking from experience here; the MK19 works wonderfully at close range. It uses a spin counting safety that makes the round incapable of arming until it has rotated a set number of times, thus a certain distance from the barrel after firing. At distances closer than about 20 meters, those 40 mm granades travelling at high velocity make nice, neat 40 mm holes in most things they hit, whether it be man, beast, or truck trailer. The m203 (same size grenade, same style fuze, much lower velocity) fired too close for arming will still shatter a man's chest like fine china.

[defiant]

We're way off hand grenades (:o ) - but that's mostly my fault for wandering topic wise and, besides, its all interesting.

So, do you know how many revolutions it takes to arm a MK19/M203 fuze - or more practically - at what distance from the shooter the round arms itself and what the kill/wound radius is of the round?

Reportedly an M79 fuze arms itself after 4.5 revolutions. That's not right on top of the shooter given the twist/rifling of the barrel...

http://img248.imageshack.us/img248/2177/m79grenadelaunchercutawmb1.jpg

... but to the extent that 4.5 revolutions is (somewhat) standard (along with the rifling twist of the M79, given the similarities between rounds and accuracy requirements) - it kind of appears that you all are a bunch of lunatics. Not that there is anything wrong with being a lunatic - but firing a grenade at close range target isn't exactly standard recommended military procedure, is it? (...not that the lunatics determining procedure know more than the guys in the field...).

Still, the impact zone for a hand grenade is 75-100 meters, and its presumed that a modern launched grenade round has an equal or greater radius, so you all appear to be cutting it a bit close.

Sure, when all hell is breaking loose you shoot at whatever is the most immanent threat -but wouldn't you prefer a couple of capable trusted point men?

[Zait]

We're way off hand grenades (:o ) - but that's mostly my fault for wandering topic wise and, besides, its all interesting.

So, do you know how many revolutions it takes to arm a MK19/M203 fuze - or more practically - at what distance from the shooter the round arms itself and what the kill/wound radius is of the round?

IIRC it's 27 feet for the M203 HE/HEDP rounds to arm. I'm not sure on the MK19 so I may have to do some digging.

I have seen idiots that fire them at targets that are too close and have them bounce off (both M203 and MK19 systems).


Still, the impact zone for a hand grenade is 75-100 meters, and its presumed that a modern launched grenade round has an equal or greater radius, so you all appear to be cutting it a bit close.


There are few people that can throw the M67 that far. The average is around 35 meters. The lethal fragmentation distance is 5meters and the injury radius is 15 meters. Anything farther out than that and it's a crap shoot if you get hit or not.

[defiant]

Just so you know, I wasn't referring to a hand grenade having a 75-100 yard kill/wound radius - but rather shortened somewhat the 100 meters safety protocol recomended by a US manual regarding grenade training ranges. Didn't phrase it very well in light.

Also, thanks for the recomendation of "Elements of Ammunition" - I picked up a copy and its a great intro (purchased Elements of Ordinance too but haven't received it yet). Feel free to PM me any other recomendations you may have on artillery/ammunution/ordinance/explosives.

I should be done compiling an ebook of "Elements of Ammunition" by tomorrow.

Next project is figuring out the methods and tooling needed to reload a grenade fuse. Shouldn't be difficult, and the pics will be posted here to get the topic back on track.

[Saugi]

NBK2000 released a nice little pdf-document (few years ago) that described the construction of a selfmade hand grenade out of a plastic-pipe. It had a pulling igniter made of matches and the frags were made of small metal balls which were attached to the grenade body with some adhesive tape.
The filler was suggested to made of acetonperoxide (which i personally would'nt use for this task)
Unfortunaltely i lost that file.

Does anybody know where i can download it again?