Fixed. Lol

What are yall doing for projectiles, just surplus dummy rounds?

It would be nice to be able to make rounds affordably. I wonder how difficult it would be to fabricate a projectile. Fab up a tail fin section from pipe and sheet metal, and maybe cast the body from aluminum or zinc.

I've got some used training rounds, but I'm working on 3D printed projectiles as well as machining some bodies. Possibly even a metal body with a 3D printed nose to work like a 40mm round.

Will a 3D printed projectile be heavy enough to set off the primer? And is 3D printing sturdy enough to contain the chamber pressure?

I'm envisioning a cast aluminum or zinc body. If necessary could probably swage it or sand it to the correct diameter. I'm pretty sure I can fabricate a tail section with either pipe or stainless tubing. Thread one end and drill some holes, then weld on tail fins.

They wouldn't be quick to make but it would cost less and be more available than what's out there now.

You could probably come up with a tail section pretty easily if you have the tools. Just look at how the originals are spot welded together.

Piece of tubing, get some fin sections plasma/laser cut, simple bending jig with a press, and a simple jig to align everything while welding. Oh and drill your holes.

It'd one of those things that would be hard to make the first one, but if you take the time to set it up right, you should be able to crank out some with repeatable results

Nice, I'm assuming you cut out the section with the demil hole?

I'm only using surplus dummy rounds right now.

Vega emailed me back, their Italian mortar tubes are 82mm for some reason. I'll probably call them later today for some clarification.

So, some thoughts after my first outing, IMO I don't think 3d printed rounds alone will be heavy enough, unless you weight them down, and maybe turn them down by a 1mm so they can go down the barrel a bit quicker.

The guys at ordnance lab and D&S creations tested 3D printed rounds, but they were launching them by loading them in the tube then setting off the lift charge manually.

Easy enough to add lead or tungsten slugs to a 3-D printed body.  And no need to turn them town - just print them 2mm smaller in diameter.  You can 3-D print wax bodies for sand casting as well.

I got the first prototype printed body this weekend. It's very sturdy, I think it will handle the pressure no problem.  Back on page 4 I put up a pic of my design. I plan on using sch 80 steel pipe for part of the fin assembly to actually hold the lift charge.  They will definitely need to be filled with ballast (I'm thinking concrete) to set off the primer.

I have also thought about casting aluminum myself. (Or finding people to commit to a 1500 pcs group buy for cast steel )



Yes I cut it off just above the big demill hole, turned it down just a little and installed the sleeve.
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If the price stays around $35 per body, I could take about 30.

Oh nice.

One thing that I'll add is that Aluminum bodies probably aren't going to be heavy enough on their own either. And I'd be worried about durability.

Vega said they make their tubes wide enough to accept 82mm mortar projectiles, but that they're also safe with 81mm projectiles. I suspect the actual ID of the tube is within spec for both designs.



Durability is less of a concern if I can re-cast at home. Recover the broken projo, melt and repour. Weight is a bigger concern. A hollow projo filled with sand or concrete may work.

They weren't fast with mine.

I talked to them on the phone the other day. Said they were still trying to figure out how to ship them....

If they'd ship the baseplate or barrel separately they could probably use UPS ground and save a few hundred over what they are charging. Shipping heavy stuff from OH to TN has been about a dollar a pound for me using pirateship. But they have a 150lb limit. Maybe I should call them and suggest that.

The giant wooden crate makes shipping difficult. I'm assuming they're sending them freight since the whole system fits in the crate.

Yeah. My Yugo came via UPS or FedEx but no crate just wrapped in cardboard and plastic.

The crate isn't a problem unless it's over their max size. I didn't check for size limitations, just weight. A crate is just a rigid box. I've gotten shipments in large metal ammo cans witha. Label slapped on the side.

I'd be tempted to pass on the crate to save a few hundred in shipping. But I also plan on putting this kit away under a pile of other stuff until I get bored with my 60mm and have time to work on it.

Damn, Bowman still has some of the Italian mortars.

I asked Destructive Devices if they would sell just the TRUMP fuses. Unfortunately the answer was no. So I guess I'll just have to make my own.

Better buy one before they run out...

BTW, found the tubing for the modding the bowman shell's fuze like that guy did in the WG forum. I just haven't gotten around to buying the threading dies yet. But will test my original homemade fuze this weekend.

Mcmaster carr
20 gauge shell holder: 89955K879

And the tube the shell holder slides in: 7767T46

If going this route with these tubes, you'll need to add some sort of stop to the bottom of the tube the shell holder slides in so it stays in place.

Tempting, but I already have the yugo up and running. We'll see later in the future.

Did you manage to get the adapter collar off?

From the solid black and white shells, yes. From the training rounds with the holes, no.

Bought a spanner wrench and locked the shells in a vise and used a breaker bar to remove them.

The ones with the holes are like staked into place. You have to make flat spots on the ring in order to get better grip and remove them.

https://www.amazon.com/dp/B091FCSQDT?tag=arfcom00-20

Small update, didn't go shooting this weekend, it was too hot lol. But I tried popping primers with the barrel at 45 degrees and a lot cleaner. Still getting misfires at 45 degrees, but they seem to get reliable pops at about 55 degrees min. so I'll keep that in mind to set it as my minimum angle.

FYI Numrich has M79 telescopes in stock.

I'm halfway hoping that they come with sights due to the increase in cost. But I'm not counting on it.

I also don't know if I care to use original sights that much as I don't know how to use them and I won't be shooting at coordinates sent in from a fire director. I'm thinking a simple angle indicator with a red dot or similar would suite me well. Probably add in some bubble levels to make sure it's all lined up.

My Bowman order just got switched to "awaiting shipment"

I get it in the sight. I was lucky enough to be given one but for LOS firing there isn't much need. I think Ben said there is a mortar aiming app.

Direct Lay Deployment of Mortar Systems:

 Direct lay is used when the mortar is emplaced within sight of the target you wish to hit, without using Forward Observer or the Fire Direction Center  
(Direct Alignment is used when the mortar is emplaced in a defilade with a crewman posted higher to act as the Forward Observer)

Index the sight deflection to 3200 mills, 0800 mills elevation for 45 degree maximum range.

Lift the cannon tube using the bipod T&E crossbar  the shift the entire gun system until the cross hair is centered on your target and  your deflection and elevation bubbles are level using elevation crank and the adjustment sleeve on bipod leg.

Fire the round.  

On impact, use the deflection knob to rotate the sight crosshairs onto the shell point of impact, then use the traversing crank to center the crosshairs back onto the target.

That should get you adjusted in to the Gun>Target deflection, with the just the range needing to be dialed in. To decrease range you crank the tube UP to a higher elevation.    81mm Mortars, generally, use both increment charges and changing the tube elevation to affect the projectiles' range.

Some US mortar systems, like the 4.2in 107mm Mortar could affect projectile range by changine just the quantity of charge increments on the round to be fired.    It was layed in on one of 3 elevations that have a specified adjustment range within each, with some overlap.  This is done for a variety of reasons, tactically, to keep the Max Ordinate (that's the highest altitude the round is going to fly) to a minimum to prevent mortar position detection by counter-battery radar, or for keeping the mortar firing well under the engagement altitudes of CAS aircraft.   Administratively, its done to keep the mortar well within a smaller impact area of a post live fire range.   4.2in M30 was layed in at either 0800, 0900 or 1065 mills elevation, 0800 mills being able to reach the absolute max effective range of the round at max charge count.  

A conflict could arise from laying in at 0800 mills elevation when in the M106A2 track mounted mode, on especially uneven or sloped ground, where when the gun is layed at 0800, the tube would be obstructed by the back edge of the mortar track's aluminum roof.     One of the Gunner's tasks is to perform a "Mask and Overhead Clearance Check" of the Gun System, by cranking the mortar down to 0800 elevation then sighting along the top then bottom of the tube to inspect for any trees, wires, vehicle components that would block the projectile flight patch.  Then he would crank the Gun System all the way up to Maximum Elevation for the particular system to perform the check again, then about 30 degrees to the left then 30 degrees to the right.   If a Gunner detects any obstructions he would notify the Fire Direction Center, who would put a notation of the deflection to the obstruction in the ballistic computer or on the plotting board or firing chart for that specific Gun.

Oh, by the way, the Mortar is one of the few weapon systems that the Gunner doesn't actually "fire" the weapon, he just indexes the fire data on the sight, aligns the mortar sight onto the aiming stakes and bubbles level.  

The Assistant Gunner actually hangs and fires the round.

Or other attached personnel like the Medic or bored S-shop soldiers are allowed to hang and drop the round after a quick safety brief how to safely do it without blowing your hands or fingers off.

They aren't on bowmans site anymore. So I assume they sold out of them. Glad I got one on order.

I saw, was surprised cause they had about 9 if their website inventory tracker is accurate. Won't be surprised if these show up in another website. Usually their inventory stays on the website once its sold out and it's marked as such.

IMA always seem to get top dollar for this kind of stuff. I could see them buying them up

Couldn't you just shave enough off the threaded end of the tube so the holes no longer align when you thread the cup on?  Just half the thread pitch would put the holes at opposite sides.

There is still a caliber sized hole in the side of the tube above the cup.

The Caliber length of these 2 models are excessively long, especially since nobody is shooting full pressure live rounds.

Historic 80-82mm mortar system cannon lengths L=Caliber Length (Barrel Length divided by diameter):
(D)  8cm GrW 34  45in   L15
(D)  8cm kz GrW 42   29in L10
(USA) 81mm M1  47in L15
(USA) 81mm M29/M29A1  36in L12
(USA) 81mm M252 50in (includes the Blast Attenuation Device BAD) L16
(USSR) 82-BM-37 48in  L15
(YUG)  82mm M69 52.1in L16
(YUG)  81mm M69B 52.1 L17
(ITA)   81mm 81/14 M35  45in L14.2

Fire Control Equipment:
There are several Iraqi and Chinese mfg copies of the Russian 82-BM-37 type mortar sights listed for sale on this page that use the round stud on sight, socket on the bipod mount (vs dovetailed slot on US type mounts)  A couple look like they use Degrees (360 increments) vs  the Mils used by USA/NATO (6400 increments)
Enemy Militaria Mortar Sights etc

Chinese 82mm Recoilless Rifle bore brushes, might be able to alter the hardware to fit on a cleaning staff, to keep your tube clear of residue build up (use with Break Free or Butch's Bore Shine)

I understand that, I've already mentioned that my tube is now at 50" after cutting it down.  My comment was in response to the suggestion that you could just face off some of the bottom so that the holes in the cup wouldn't line up.  You still have to do something about the giant hole in the side.

Supplier has a very shady history and hasnt answered the phone, returned emails or returned voicemails in quite some time
Approach with caution

Did Dangerous Bob produce tubes for these?

I am in.

For the Yugo, yes. Not sure if he has any left.

Update 2nd outing.

Cleaned the barrel a day before, and raised the angle to 50 degrees. This is the minimum degrees before I start having misfires.

Reached 190-200yds with 50 grains of bullseye which is my my max distance with line of sight.

Still need to do load data for a higher angle and see if I can get it to 200yds as well. We'll see when I get to this as we're entering summer and the days down here are hot as hell lol.

The barrel gets real dirty after each fire session of 4rounds so gotta scrub and wipe it down with a rag and some clp on it after every fire session otherwise I'll start having misfires at 50 degrees.

Total misfires today was 1, needed to wipe down the barrel. Over all, success for today.

Also tried my ghetto impact fuze but it didn't work. Looks like the shell will need a carrier to provide the adequate weight so it can slam forward into the firing pin. Will revisit this later.

Reloading setup.




69 degree angle, almost lost sight of the shell in midflight lol.

That's awesome.  You could hunt cats with that.

I was thinking of pigs, but then thought, what happens if it doesn't die and it runs away with my $120 shell. lol

You could tie a line to it, then just reel the hog in.

I got tracking info for my Italian 81mm today.

LOL