Help with M106A1 mortar carrier

Hello all, I’m getting ready to start on the M106 conversion from Hobby Link. The 3D printed parts look top notch. I have scoured the web doing my research but I still have some questions I am hoping the community can help me with. Here we go:

  1. Just like the old Tamiya release, Hobby Link provides a fuze rack, but nothing to fill it with. According to my research, the fuses came in an N335 fuze can. I think they are the same size as a 50 cal ammo box. Can anyone confirm this?
  2. The rounds for the 4.2 in mortar come in black fiber tubes. Does anyone have information on the markings on theses tubes? I am mainly looking for the High-explosive 4.2-inch cartridges, M329A1 and M329A2 and the White phosphorus smoke 4.2-inch cartridge M328A1 rounds.
  3. The old Tamiya kit has things stored under the mortar round racks (part C4 on the left and parts C6, C11, and C12 on the right. What do these represent? I assume at least one is a case for the sighting unit. Unfortunately these are not represented in the Hobby Link conversion.
  4. If the mortar is being fired from inside the carrier, are the aiming stakes still used?
  5. Looking at lots of Vietnam photos, I never see anything outside of the carrier during firing aside from ready rounds, so no fiber tubes, fuze cans, etc. So are the empty fiber tubes put back into the racks.
  6. And lastly, does anyone have any interior pictures. Keep in mind that I have pretty much exhausted Google search. I have read that Verlinden’s War Machine #2 has some good reference pictures, but I am not willing to pay $74 for this.

Any answers are greatly appreciated.

Shipping carton for 4.2" (107mm) mortar shell.

Close up of markings on tube.

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Interior of the M106 Mortar Carrier. Hope this helps.

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Unfortunately I only have interior photos of the upgraded tracked four deuce.
And yes, aiming stakes are used.

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M329A2 4.2" HE Mortar round

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M335A2 Illumination round.

I can assume the WP mortar round is painted light green (Tamiya XF21 Sky) with a red band around the full circumference of the round.

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More…

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From the RP Hunnicut Bradley volume. I dunno if these will help, or not:

M125A2:

M106A2

M106A3

in Vietnam, most mortar carriers shot line of sight. Yet the aiming stakes were a need be thing for indirect fire. The problem was in getting somebody out there to lay the tube. So your back to line of sight. Not all that bad considering the idea that you’re shooting at less than 1500 yards. You can see the impact often and adjust from there, or if you’re lucky there’s somebody correcting your fire on the other end. Still for precision shooting; you’re gonna need aiming stakes. Just doesn’t happen often. The real problem with a CAV outfit is that they were at the spear head and the folks back in the rear didn’t wanta be there. Plus generic arty was top priority with them.

A WP round was painted a very light grey (almost a very light blue). Usually shot with a timed fuse (painted black), but not always. They would use a standard PD fuse (bronze color) a lot of the time. Illumination was also a very light grey color, and always shot with a timed fuse. Funny thing was that the rounds were similar in color, but also shaped differently. One was somewhat heavier (can’t remember which one). The main job we saw with a four duce was illumination, and most HE was shot with either an 81mm or 82mm (we had both). Reason why? The four duce round stayed aloft much longer.
gary

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This one is a Dutch Army M106A1. Don’t know how much it differs from a US one…

H.P.

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H.P.

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Hope the Hobby Link doesn’t share the same problem as the Tamiya kit and have the mortar in the travel position. To put it into action you lift the barrel up and it snaps into the firing position.

I don’t know if anybody takes the time to take the paper off but it’s cardboard tube with wax coating and paper over that. It’s not a sensitive item so the empty tubes probably get tossed over the side so it’s not confusing as to which tubes are full.

This is from the late 80’s. You take one leftover box (which holds 2 rounds) and make the cheese charge box full in increments of 1/8 charge. 4.2" is different in that you fire at a fixed elevation and manipulate the charge for range.

The fuze can is about the same size as a .50 cal can but we prefuzed the rounds before live fire so the fuze rack had other crap in it.



ammo_prep

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We did have rounds inside the track if practicing hip shots (driving down the road to firing position in quick time). Mostly in the ready rack.





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Frenchy, that first pic is a 81mm mortar in a M125 track.

Thank Paul. I’ve edited my post.

H.P.

My unit along with the rest of 2AD (Fwd) went to Desert Storm attached to 1ID a year after I left.

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i think the WP rounds were heavier than HE, i seem to remember reading about someone calling arty and the WP rounds were falling a little short of target. the author said the shory fall was because of the weight of the WP round.

When firing artillery rounds or mortar rounds, all of that data is taken into account. Or should be.
Willie Pete can fly erratically if not stored properly. If you are doing a diorama with Willy Pete the projos or rounds must be stored vertically.

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Yes! Very true. We had the same problem with tank rounds. The WP, when carried, had to be upright. Very touchy stuff.
Ken

for sure one or the other was heavier than the standard HE round. Plus there is the displacement factor. On the first volley the gun (or whatever your shooting) move slightly rearwards. Usually about six inches. After that everything settles in. With a mortar that’s not much of a factor as the angle of the tube is much greater. Six inches isn’t much, but when you factor the change of angle for five or more miles it becomes an issue. A good crew knows this and takes care of it before the first shot. Still a lot of them are still in the learning curve (not a pun). Myself; I never was in love with illumination rounds as the light screws with your eyes, and makes everything look like it’s moving. Trip flares are even worse.
gary

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always standing strait up in the shade. Samething with illumination. We stored all our rounds vertically if for no other reason to make them easier to pick up. On the gun it’s a different story. Some guys wanted them laying down, but other vertically. I preferred vertical.

The temp of your powder will make or ruin your day just as well. Powder needs to be in the shade or at least covered with a tarp. This time of the year it’s not a big deal, but let it hit the hundred degree mark and things change. I’ve taken powder temps in the mid 140’s (in the shade), and when it get’s above 100 degrees outside they do this every three to four hours on each piece till the sun goes down. Air currents can also ruin your day. There may be a wind shear show up in a small area your shooting in. You will never know it on the ground, but it’s there.
gary

Ah Yes, I remember “Cutting the Cheese” in Graf back in 82.

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