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81mm Mortar barrel/tube/build info (Page 4 of 15)
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Originally Posted By walkinginadangerzone: Who? Originally Posted By walkinginadangerzone: Originally Posted By MHIDPA: That's cool. interesting that the pipe threads work. Also, these guys are doing some 3D printing that could apply to this project. I got the shipping notification for my sleeve material yesterday. Who? Crap, forgot to add the link. D and S creations |
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Originally Posted By Sinister: This is the 81mm mortar sub-caliber trainer. The sub-cal barrel fits inside the 81mm tube. Each round is fired with a 12-gauge blank, and a .22 blank gives off a "Pop" when it impacts: https://www.ar15.com/media/mediaFiles/18978/81mm_sub-cal_trainer_jpg-3160676.JPG Almost right. They're a .22 blank used as the launching charge. I had one for quite some time but got rid of it as it would kill me if I ever lost one of the rounds. They also come with spacers for the 60mm and 4.2 inch mortar. |
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Originally Posted By MHIDPA: Originally Posted By walkinginadangerzone: Originally Posted By MHIDPA: That's cool. interesting that the pipe threads work. Also, these guys are doing some 3D printing that could apply to this project. I got the shipping notification for my sleeve material yesterday. Who? Crap, forgot to add the link. D and S creations Ah, lol yeah, I linked their YouTube video in the weaponsguild thread. Their video just released today too, it was pretty good with lots of ideas.lol I seriously need a 3d printer. |
| I've got one that I haven't used in a while. I'm thinking that In a traditional mortar like ours, metal is going to be required in the fin assembly. I think that the shotgun blank would blow a plastic one apart. But perhaps I could print fins that could slip over a piece of pipe to make the assembly. I'm going to draw something up in Solidworks this week. |
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For sure, I think it's the 1 inch pipe that the 12G shell fits in. Having the 3d printed fin assembly slip over the pipe and making sure the vent holes overlap could probably help in them not blowing up into pieces. Lol. Also got to cap off one end so it doesn't just blow everything through the other opening in the pipe. But 3d printing bodies is where it could get interesting. I believe Ben was talking about this in this thread well. |
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No doubt on printed projectiles. Those guys were printing fuses and everything. BTW did you see the WG thread where the guy modified the dummy fuse to work with a 20Ga blank? ETA, it looks like SCH 40 3/4 Pipe has an ID of .824 which is probably too big to hold a 12ga shell without a cap. My inert round measures .809 which is a perfect snug slip fit. SCH 80 has an ID of .742, so it could be bored pretty easily. A sold base on the projectile would negate the need for a plug on the fin assembly. |
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Originally Posted By MHIDPA: No doubt on printed projectiles. Those guys were printing fuses and everything. BTW did you see the WG thread where the guy modified the dummy fuse to work with a 20Ga blank? ETA, it looks like SCH 40 3/4 Pipe has an ID of .824 which is probably too big to hold a 12ga shell without a cap. My inert round measures .809 which is a perfect snug slip fit. SCH 80 has an ID of .742, so it could be bored pretty easily. A sold base on the projectile would negate the need for a plug on the fin assembly. Originally Posted By MHIDPA: No doubt on printed projectiles. Those guys were printing fuses and everything. BTW did you see the WG thread where the guy modified the dummy fuse to work with a 20Ga blank? ETA, it looks like SCH 40 3/4 Pipe has an ID of .824 which is probably too big to hold a 12ga shell without a cap. My inert round measures .809 which is a perfect snug slip fit. SCH 80 has an ID of .742, so it could be bored pretty easily. A sold base on the projectile would negate the need for a plug on the fin assembly. Link to the thread? What type of solid base are you thinking of for the projo? Edit: A little insight into their PD fuze. lol @DandSCreations @DandSCreations 21 hours ago Nail, primer, and primary explosive compound. Proper fitment is critical to prevent tube detonation. Also incorporates a safety pin for handling, the whole detonator unscrews with a wrench in case there is need for safe transportation. |
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https://weaponsguild.com/forum/index.php?topic=97065.0 Basically I'm thinking that the body would have a blind hole that the fin assembly threads into. Essentially capping the fin tube. |
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Worked on my firing pin tonight. Reprofiled the tip that had been milled off and set the shoulder back to get protrusion. I ended up with .058 protrusion. Attached File Attached File Attached File Before and after. Attached File Attached File |
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I got a pretty big step finished tonight. I got my sleeve completed. I got a piece of 4" OD X . 25 wall A513 DOM tubing and turned/bored/threaded it. Next step will be to face and turn the beach end of the barrel, press on the sleeve and weld it in place. Also weld the bore obstruction holes and then turn/smooth everything out and I should be ready to fire. Attached File Attached File Attached File Attached File |
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Started some Solid models tonight. Body and fin assembly. I think I'll use a piece of SCH 80 3/4 Pipe to hold the 12ga lift charge and the fins. I can epoxy the fins to it to use as a drill template and the shoulder would also keep them in place. Attached File Attached File |
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Originally Posted By MHIDPA: Started some Solid models tonight. Body and fin assembly. I think I'll use a piece of SCH 80 3/4 Pipe to hold the 12ga lift charge and the fins. I can epoxy the fins to it to use as a drill template and the shoulder would also keep them in place. https://www.ar15.com/media/mediaFiles/60540/1000002554_jpg-3175125.JPGhttps://www.ar15.com/media/mediaFiles/60540/1000002553_jpg-3175126.JPG What is the purpose of the smaller cavity between the fins and nose? And how do you plan to make that? 3D printing? |
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Originally Posted By MHIDPA: Either cut an extraction notch in the base or just unscrew the fin assembly and punch it out from the top. Probably the latter, because the hull gets blown out through the vent holes. Ah, b/c the shell is retained in the projectile, not left behind in the tube. Nice. |
Death to quislings.
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Originally Posted By MHIDPA: Started some Solid models tonight. Body and fin assembly. I think I'll use a piece of SCH 80 3/4 Pipe to hold the 12ga lift charge and the fins. I can epoxy the fins to it to use as a drill template and the shoulder would also keep them in place. https://www.ar15.com/media/mediaFiles/60540/1000002554_jpg-3175125.JPGhttps://www.ar15.com/media/mediaFiles/60540/1000002553_jpg-3175126.JPG Looks good. |
Finally got the barrel about a week or two ago and finished painting it along with the cup and other small parts that I had left over that needed paint from when I refinished the bipod. All I need to do is add the white line like on the factory tube and yellow fill the stamped info on the cup like how it came from factory. Just two or three more weeks till test fire.  Also ended up extending the threads on the pipe so I could thread it through the threaded ring adapter and then just thread on the cap to have a more astheticly pleasing fuze head. Will see how this works once I do the test fire. 
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Originally Posted By Sinister: Just as an aside, you don't need a full-length tube. The WWII US M2 81mm was pretty short. https://www.ima-usa.com/cdn/shop/files/[email protected]?v=1695858356 But the Germans made the 8,0cm kurz Grenat Werfer 42 "Stummelwerfer" (Stubby) or sometimes called Slingshot, an 80mm short tube on a copy of the French Brandt 60mm Bipod and Baseplate. Bowman has a few of the 81mm tube/baseplates left for sale, I thought about doing the kz GrW 42 using one of the repro 60mm M5 baseplates from Sarcoinc.com Since folks are just "werfing" trainer-type low pressure rounds, there's no point carrying around all the extra weight. Used to be able to find the M5 Bipod main crossbars NOS for about $100. Some 1"-10TPI Acme threaded rod for the traversing and elevation mechanism. Attached File Attached File Attached File Something like this using 81mm M800-series ammunition at reduced charge, like were allowed to be used in the older US M29A1 Mortar System, for SOF use in Afghanistan, a little heavier than the M224A1 60mm, but with a much larger casualty radius , and ability to use the newer PGM series rounds. |
1995 M1025A2 5SFG GMV ODA525 "Hammerhead"
1995 M1025A2 3SFG GMV ODA391 "Roughnecks"
1984 Chenowth M1040 Fast Attack Vehicle 061 " Horney Toad"
1995 M1025A2 3SFG GMV ODA391 "Roughnecks"
1984 Chenowth M1040 Fast Attack Vehicle 061 " Horney Toad"
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Originally Posted By MHIDPA: Looks good. I should have a good update this week. Did you do anything to repair the holes in the cup? No, mine was one of the unmolested ones, so it only has one but it doesn't go all the way to the bottom so the cup and the barrel should seal up tight. I might get someone to weld it up and fix the threads in the welded section later. Sharpied the area in the threads where the hole lines up, this is with the cup just screwed down all the way. 
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very nice, never seen one that looked that good, they all had 4, 5 layers of paint layers showing through chips. I did strip an M3A1 aluminum 81mm baseplate down to anodized metal then painted it OD for a dog & pony show for the 4 Powers in Berlin. |
1995 M1025A2 5SFG GMV ODA525 "Hammerhead"
1995 M1025A2 3SFG GMV ODA391 "Roughnecks"
1984 Chenowth M1040 Fast Attack Vehicle 061 " Horney Toad"
1995 M1025A2 3SFG GMV ODA391 "Roughnecks"
1984 Chenowth M1040 Fast Attack Vehicle 061 " Horney Toad"
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Originally Posted By MHIDPA: Looks great! Now go shoot it! Originally Posted By MHIDPA: Looks great! Now go shoot it! Thanks, unfortunately, it has to wait till next weekend.   Originally Posted By stoner63a: very nice, never seen one that looked that good, they all had 4, 5 layers of paint layers showing through chips. I did strip an M3A1 aluminum 81mm baseplate down to anodized metal then painted it OD for a dog & pony show for the 4 Powers in Berlin. Thanks. |
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Do these mortars have a specific place on the tube that the clamp goes? The more I look into them, the more I see how many ways people have tried to improve on them. So many different designs and ideas. My buddy has a Russian 50mm Mortar with fixed elevation but it bleeds off Gass at the bottom to determine range. My 60mm Spanish Modelo 51 sits with a tripod instead of bipod, and the tube slides freely in the "clamp," so recoil doesn't affect the sights and you don't need a shock absorber setup. Some (m224 for example) have fixed spots for the bipod to clamp on to, so you just kinda set it up and adjust to the angles you need. My favorite recent realization is how the Japanese type 89 knee mortar has a rifled barrel, and some vents from the launch charge push out on the copper(?) driving band during firing. So it's undersized when loading, then engages the rifling on firing. So no lining up the rifling. Sorry for my mortar fascination rant. |
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Originally Posted By SGT-Fish: Do these mortars have a specific place on the tube that the clamp goes? The more I look into them, the more I see how many ways people have tried to improve on them. So many different designs and ideas. My buddy has a Russian 50mm Mortar with fixed elevation but it bleeds off Gass at the bottom to determine range. My 60mm Spanish Modelo 51 sits with a tripod instead of bipod, and the tube slides freely in the "clamp," so recoil doesn't affect the sights and you don't need a shock absorber setup. Some (m224 for example) have fixed spots for the bipod to clamp on to, so you just kinda set it up and adjust to the angles you need. My favorite recent realization is how the Japanese type 89 knee mortar has a rifled barrel, and some vents from the launch charge push out on the copper(?) driving band during firing. So it's undersized when loading, then engages the rifling on firing. So no lining up the rifling. Sorry for my mortar fascination rant. No worries, all this is interesting to me, anyways lol. That said, the og yugo barrels don't have a clamp index point on the barrel other than a vertical painted white stripe that I believe is used for bore sighting. A while back I was trying to find the area in the tube to best place the clamp on. I was going by what the brochure of the system says, "Vertical field of action 45° to 85°". I used an angle gauge, set the bipod clamp's height to it's lowest point and set the clamp close to the taper on the tube, then ran the clamp up the barrel until it hit 45 degrees, marked the barrel with a white line across. If I remember correctly, if you keep the bipod clamp set in the 45 degree spot, you won't hit further than 60 70 degrees give or take when you elevate the barrel, so you have to move the clamp back down the tube some more till you get the desired high angle. The ukrainians and russians put two index points on their barrels, one for low angle fire and the other for high angle fire. In the pic below, you can see where the barrel clamp is on the tube, then if you look up the barrel, you'll see a spot where the clamp fits into as well. 
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Originally Posted By walkinginadangerzone: Their next shipment of 81mm mortars are the Italian copies of the Brandt Mle 27/31. I really need them to import more shells tho. Oh I know. And if you fuckers don't leave me one, I'll be pissed. I need one to reverse engineer. |
Lightning from the Sky, Thunder from the Sea!
Twitter/Instagram: benunsuppressed
https://americanpioneercorps.org
Twitter/Instagram: benunsuppressed
https://americanpioneercorps.org
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Originally Posted By juan223: Would cheese work/combust with how you guys are setting these up? And is it even available and legal to possess? Idk about cheese specifically but if you roll it back to WW2 increment charges, those would work fine. Operational range for these is ~9k PSI, 15k PSI is a pissin hot modern full cheese nato guided round. So Idk if I would want to throw surplus cheese in even if you somehow had it. Ill be experimenting with inc charges once I finish shell casting |
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Even full WW2 style increment charges are at about 720 gr of powder including the lift charge. I think theoretically you can set off factory cheese charges with a home rolled lift charge, not sure if amount of powder on the lift charge will affect it (modern ammo tech manuals say not to fire a full increment charge with older mortars, but you can probably do charge two). But like 7insert said, don't know where you'd find live cheese charges, you can find inert ones from time to time tho. |
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Originally Posted By walkinginadangerzone: Their next shipment of 81mm mortars are the Italian copies of the Brandt Mle 27/31. I really need them to import more shells tho. Almost $1500 per, not quite as good as the yugo deal, but these are pretty much an exact version of the US WW2 M1 81mm mortar IIRC. I am planning on buying one if I get the chance. Should have my 60mm Spanish model 51 done soon. Just got word that the cup is finished. |
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Originally Posted By juan223: Would cheese work/combust with how you guys are setting these up? And is it even available and legal to possess? I've met some guys that made/make increment charges out of empty tea bags. You can nitrate them if you want the best burn, but they typically exit the tube anyway. Just use bullseye powder for the charge. I was thinking of trying to 3d print donut charges out of something like foam PLA or TPU, but in reality I'll likely never shoot far enough to need them |
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Originally Posted By SGT-Fish: Almost $1500 per, not quite as good as the yugo deal, but these are pretty much an exact version of the US WW2 M1 81mm mortar IIRC. I am planning on buying one if I get the chance. Should have my 60mm Spanish model 51 done soon. Just got word that the cup is finished. Originally Posted By SGT-Fish: Originally Posted By walkinginadangerzone: Their next shipment of 81mm mortars are the Italian copies of the Brandt Mle 27/31. I really need them to import more shells tho. Almost $1500 per, not quite as good as the yugo deal, but these are pretty much an exact version of the US WW2 M1 81mm mortar IIRC. I am planning on buying one if I get the chance. Should have my 60mm Spanish model 51 done soon. Just got word that the cup is finished. Nice, did you get someone to make you a cup from scratch? |
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Originally Posted By SGT-Fish: I've met some guys that made/make increment charges out of empty tea bags. You can nitrate them if you want the best burn, but they typically exit the tube anyway. Just use bullseye powder for the charge. I was thinking of trying to 3d print donut charges out of something like foam PLA or TPU, but in reality I'll likely never shoot far enough to need them Originally Posted By SGT-Fish: Originally Posted By juan223: Would cheese work/combust with how you guys are setting these up? And is it even available and legal to possess? I've met some guys that made/make increment charges out of empty tea bags. You can nitrate them if you want the best burn, but they typically exit the tube anyway. Just use bullseye powder for the charge. I was thinking of trying to 3d print donut charges out of something like foam PLA or TPU, but in reality I'll likely never shoot far enough to need them I was wondering how well the old Russian style increment charges could be replicated. They seem like a cotton rag sowed into a tube filled with powder that you just tied around the fins shaft. |
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I had Vega/destructivedevices.com make me a cup after working out a deal with them. I'll keep the details private but it ended up being a mutually beneficial arrangement. I may still make my own permanent/welded cup and tube as I have a hankering for a commando style mortar. There were some 81mm increment charges the US used between the cheese sheets and the "C" donuts. They were long tubes of cotton(?) That had extra string on them and they were tied around the tail section. These were used in the rounds that had tapered tail assemblies. I have seen a guy that had some very nice repros made by his wife with here sewing machine. You just need to use a material that is thin and flammable enough that it won't clog up the tube/firing pin. Though even the military mortars show bits of charges flying out the tube behind the projectile. Tea bags are just convenient as they are already mostly assembled and you can buy them in packs on amazon. |
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Originally Posted By SGT-Fish: I had Vega/destructivedevices.com make me a cup after working out a deal with them. I'll keep the details private but it ended up being a mutually beneficial arrangement. I may still make my own permanent/welded cup and tube as I have a hankering for a commando style mortar. There were some 81mm increment charges the US used between the cheese sheets and the "C" donuts. They were long tubes of cotton(?) That had extra string on them and they were tied around the tail section. These were used in the rounds that had tapered tail assemblies. I have seen a guy that had some very nice repros made by his wife with here sewing machine. You just need to use a material that is thin and flammable enough that it won't clog up the tube/firing pin. Though even the military mortars show bits of charges flying out the tube behind the projectile. Tea bags are just convenient as they are already mostly assembled and you can buy them in packs on amazon. Nitrided tea bags is definitely the way to go. |
Lightning from the Sky, Thunder from the Sea!
Twitter/Instagram: benunsuppressed
https://americanpioneercorps.org
Twitter/Instagram: benunsuppressed
https://americanpioneercorps.org
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Originally Posted By SGT-Fish: I had Vega/destructivedevices.com make me a cup after working out a deal with them. I'll keep the details private but it ended up being a mutually beneficial arrangement. I may still make my own permanent/welded cup and tube as I have a hankering for a commando style mortar. There were some 81mm increment charges the US used between the cheese sheets and the "C" donuts. They were long tubes of cotton(?) That had extra string on them and they were tied around the tail section. These were used in the rounds that had tapered tail assemblies. I have seen a guy that had some very nice repros made by his wife with here sewing machine. You just need to use a material that is thin and flammable enough that it won't clog up the tube/firing pin. Though even the military mortars show bits of charges flying out the tube behind the projectile. Tea bags are just convenient as they are already mostly assembled and you can buy them in packs on amazon. That's right, forgot about those. The Vietnam era-ish charges. Also saw that thread. |
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Originally Posted By MHIDPA: Looks like Destructive Devices is making TRUMP rounds again in 60 and 81. That's good. Bonetti makes their own version that is pretty cool and a bit smaller. Both are too pricey for me to buy more than a couple, so I'll work on making my own. I bet they'd be great packed with chalk and plugged with plastic caps |
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Originally Posted By SGT-Fish: That's good. Bonetti makes their own version that is pretty cool and a bit smaller. Both are too pricey for me to buy more than a couple, so I'll work on making my own. I bet they'd be great packed with chalk and plugged with plastic caps Originally Posted By SGT-Fish: Originally Posted By MHIDPA: Looks like Destructive Devices is making TRUMP rounds again in 60 and 81. That's good. Bonetti makes their own version that is pretty cool and a bit smaller. Both are too pricey for me to buy more than a couple, so I'll work on making my own. I bet they'd be great packed with chalk and plugged with plastic caps Bonetti will only sell if you F1 each round as a DD tho. (unless you have the licenses to make DDs forgot which one it was in which case, you can just buy them.) |
81mm Mortar barrel/tube/build info (Page 4 of 15)
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