I am thinking of of making a 37mm AT-gun M3A1 for a project, the main idea it to be something allong the lines of what Gunman have in their D-Day Carentan video.
http://www.youtube.com/watch?v=IsqVpVIbyUw
So what are the legalities and how to do's I need to keep in mind?
http://image14.webshots.com/14/2/42/53/ ... wXW_fs.jpg
Many of you may remember the video of these jumping in the air with jeeps.
I am thinking Landrover wheels may do the trick, they don't appear to have any suspension but I may fit indispension units.
Free speech is expensive these days!
Gunman's ones use a black powder charge for the bang and flash bit. The down range ballistics are taken care of by a marshal with a big pyro. They fire no projectile so don't need any form of license as far as i'm aware. You could use a propane set up
Well that would need a Black Powder licence to buy the stuff unless they are pre-made pyro.
Free speech is expensive these days!
Well that would need a Black Powder licence to buy the stuff unless they are pre-made pyro.
They are pre-made electronic ignition 'bag' charges.
These charges fit inside a "shell" casing which is a very thick tube, about 10"-12" long with one end capped off (albeit, for a small hole drilled for the ignition wires to exit through) which the bag charge is then housed in. These "shell" casings not only act as a safe way to contain the blast (not relying on the faux-barrel of the prop field gun) and direct the blast away from the gunners, but also as a safer and more realistic way to load the bag charges into the barrel of the field gun. The field gun must have a good secure breech on it's faux-barrel, and also another small hole drilled for the wires to exit through.
The blast from the charges is usually enough to cause a bit of back force which the field gun absorbs. I've always thought that if the faux-barrel could be mounted on a cradle or slider with a degree of longitudinal movement, then the blast from the charge could create a pretty cool looking "recoil" motion of the faux-barrel.
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
The blast recoil must not be underestimated. I don't know how much black powder was being used in the charges at Anzio, but after a few shots, both gun barrels became unsecured due to the recoil. Therefore, the barrel must be firmly connected to the main gun structure.
You've got nothing to ein, zwei, drei, vier
I think the over-riding consideration when making something that goes bang Nigel is where would you stand if there was an equipment failure and someone got injured? How would you stand if you were sued? How are you insured in case you got sued and how have you complied with insurer's stipulations that help ensure you aren't sued in the first place (risk assessments and the like). Gunman's firing system was developed by TLSFX and so expertly made (even so the equipments surrounding them suffered physical damage).
I'd say no matter how cool a breach firing AT gun would be the practicalities mitigate against doing it. An easier and safer solution might be to blank the barrel off 4" down from the front end and just drop a thermobaric into the blind end. It will go bang, big puff of smoke, job done. OK, AT guns aren't muzzle loaders but meh.
Thanks
I will probably keep it simple and as cheap to use as I can, I can't see anyone else helping to fund the ammo for it so it will be up to me.
Just the fact of having one here in the North will be a bonus, it should be easy to make one just to use thermobarracks of varying sizes.
I can work out a safe breach system and vent the explosion under the barrel just in front of the blast shield.
No large thermos will be used as I am a cheap skate 
I will use some stainless steel around the moving breach component surfaces to reduce failure from corrosion. I have an idea forming on how to do it.
I may work out a way to duct some of the smoke back to the front of the barrel but not enough gas for any projectile propulsion if someone stuck a spud in there etc. Purely the fact that smoke tends to rise so provide a zig zag route back to the muzzle.
As said I want suspension and not a bouncing load when I tow this so there will be cheating going on here but I will try and get a reasonable look to the gun if I can.
An other option is to use shot gun blanks and maybe fit them in a dummy shell. Box of 50 for £25.
http://www.hfmgroup.com/professionalsup ... ition.html
Free speech is expensive these days!
I suspect if you start making a barrelled "gun" which fires using shotgun blanks, that Mr Plod may take a lot of interest.
BTW, I've a cast 4-spoke handled wheel that would look perfect for the evelation wheel as shown in the photos.
It's a bit heavy, so I don't know if posting it to you'd be a viable option!
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
BTW, I've a cast 4-spoke handled wheel that would look perfect for the evelation wheel as shown in the photos.
It's a bit heavy, so I don't know if posting it to you'd be a viable option!
That sounds great mate!
Will have to sort something out maybe but I will check out a local scrap guy first.
I suspect if you start making a barrelled "gun" which fires using shotgun blanks, that Mr Plod may take a lot of interest.
The barrel will not be gas venting as I said but I can work out a way for smoke to rise and duct it back to the barrel.
12g blank is probably the easy and cheap way to go with this, it won't be as laud but is simple and quite safe to do compared to other options.
The main problem to start with will be finding wheels and making the elevation system work and look good.
A Mondeo space saver wheel may be an option but with a large profile tyre fitted.
I may be able to sort out a hub easy for a ford 5 stud.
Free speech is expensive these days!
I finally managed to find the video I'd seen a while back;...
Everyone please watch this!
http://www.youtube.com/watch?v=fD2zU7iXAsE
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
Yes nice vid McVickers there are a few types shown on youtube that fire stuff but I think I will keep with just noise as it is less hassle and can be used for re-enactment as well as airsoft. Once you fire stuff you are in a mine field of problems with power limits etc.
Free speech is expensive these days!
The dummy shell could be your "pressure-bearing" part. Solid brass, bored to take the shotgun blank, and vented radially to allow the gasses to escape, but not bored long/large enough for a live shotgun shell. That way, the "barrel" could be made of materials and construction totally unsuitable to a gun to avoid legal problems.
The wheels in the colour photo look like standard jeep wheels/tyres, but in the "flying" photo, they look a bit larger. It might just be the lighting, or the one in that photo has different wheels.
WRT recoiling barrel: It's a shame it's not one of those guns that has a recoil damper cylinder. You could then use it in reverse to create recoil - kind of a huge GBB. 
Yeah, I agree...
...but it's so damn cool I couldn't help but share it 
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
The dummy shell could be your "pressure-bearing" part. Solid brass, bored to take the shotgun blank, and vented radially to allow the gasses to escape, but not bored long/large enough for a live shotgun shell. That way, the "barrel" could be made of materials and construction totally unsuitable to a gun to avoid legal problems.
That's how the Gunman ones work. The bag charges are in a over-engineered 'shell' tube, which allows the faux-barrel to be non-weapon grade 
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
I think Mondeo 16"wheels should look OK they are the same size as my jeep wheels I would just have to find some suitable tyres for them to look right. If I search a few scrap yards I should find the space saver wheels and some rear hubs and or suspension parts.
As I say cheap skate me
Scaffold pipe and what ever I can find that looks good with a few mods for a barrel, angle grind a slot under it and weld pins across inside also no straight path from charge to muzzle easy.
I have several 30mm - 40mm steel shell casings I have for dummies to dress the tank at shows so all I have to do is weld a steel pipe inside them with side venting hole's and have the shotgun blank in the end.
Old singer sewing machine wheel for elevation if push comes to shove 
Free speech is expensive these days!
How about down-scaling and building a 10.5cm Leichtegeschutz:
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
LOL - Looks like a sawn-off FlAK 88 on a shrunk mount!
I did consider trying to make something half way between German and US so it would swing both ways as they say but you always have a captured weapon as an excuse.
So to tow with my jeep a US 37mm is best I think.
I have been digging about and can get a pair of 500kg suspension units for £75 and purpose made hubs for £37.50 each. So I still have the wheels to decide on old Mondeo would be cheapest from a scrap dealer but I don't know about tyres for them yet.
Other option is get proper jeep wheels with bar grips but the best place to buy them cheap is Beltring.
I can get 16" trailer wheels with tyres for about £110 each.
http://www.tyreline.com/trailer_caravan ... spx?TID=53
This is all the expensive stuff the rest will be scrap metal if I am lucky.
I am told to be legal you need suspension so I don't think making it like the original gun would be legal anyway these days.
Free speech is expensive these days!
I finally managed to find the video I'd seen a while back;...
Everyone please watch this!
http://www.youtube.com/watch?v=fD2zU7iXAsE
Canister shot! When you absolutely positively have to stop that banzai charge, accept no substitutes!
To the tune of "Mademoiselle from Armentières"
Napoleons army ran away, As you do
The guard stood firm for Frances Pride, As you do
They said the guard will stand and die
But we heard what their Colonel cried
It wasn't pretty I tell you.
Resistance is fertile
