"Boulder blaster" commercial or self made.

[Assembler]

"Boulder Buster", uses standard 12 gauge cartridges.
Anyone use one or know of someone who uses one?

I did come across someone over seas who made one. Just checking here if anyone uses one.
Thank you.

 

[RTR]

No.But this stuff is cool

 

[Assembler]

No.But this stuff is cool

I have seen this before. However it is a cool product.

The commercial shotgun product I believe is made Australia. See the attached file.

 

[Assembler]

I have seen this before. However it is a cool product.

The commercial shotgun product I believe is made Australia. See the attached file.

Warning this load is too dangerous to put in a regular thin barrel shotgun.

 

[BlasterJ]

The US made one I am familiar with doesn't use regular shotgun ammo. The old one used a special either 10 or 12ga blank round. I believe the new one uses a proprietary size. Info is here:

Search | com.com

boulderbuster.com

 

[Assembler]

The US made one I am familiar with doesn't use regular shotgun ammo. The old one used a special either 10 or 12ga blank round. I believe the new one uses a proprietary size. Info is here:

Search | com.com

boulderbuster.com

Thanks I have seen this. The price is around $5,000 for the barrel gun and around $950.00 - $1,100.00 for a box of shells / rounds.

 

[Assembler]

One can order solid brass shell cases online for around $32.00 for 10 brass 12 gauge cases and load them yourself.

 

[N-Lionberger]

Good luck finding reloading components, between Covid and the current political climate reloading components especially primers are few and far between, what can be had has dealt with a pretty extreme price mark up.

 

[Assembler]

Good luck finding reloading components, between Covid and the current political climate reloading components especially primers are few and far between, what can be had has dealt with a pretty extreme price mark up.

Yea I hear what you are saying. However I have repaired with about 800 primers to devote to this project if necessary.

By the way it will be about 2 years plus before more primers will be made for non military or public.

 

[Assembler]

By the way one does not need to use only "ball type powder" to make the shells or loads. Be warned that the pressures will be higher then normal shotgun shells. Do not use in a normal thin barrel shotgun barrels.

 

[N-Lionberger]

I looked up the Boulder Blaster and found it appears the shells used .22 blanks like you use in a Ramset as their primers the company even referred to them as rimfire primers. Ramset blanks are easy to find at most any hardware store. Interesting stuff to think about. I wonder if that is something those Australians did as far as firearm law as they are pretty strict over there in that regard. I assume a shot shell with a 22 blank as a primer would need a special offset firing pin and wouldn’t be functional ammunition in a regular shotgun possibly skirting around ammunition sale restrictions.

 

[N-Lionberger]

Doesn’t look like it would be too hard to make if you have a lathe and some machining experience. Could be really simple mechanism just a spring loaded firing pin held up with a pin that could be yanked out with a lanyard. For the the 22 blanks you could probably get away with a firing pin ground to look like a flat head screwdriver. As far as powder you wouldn’t necessarily need ball powder as you stated as it relies on filling the drill hole with water and since you can’t really compress water, it has to go somewhere.

 

[BlasterJ]

Doesn’t look like it would be too hard to make if you have a lathe and some machining experience. Could be really simple mechanism just a spring loaded firing pin held up with a pin that could be yanked out with a lanyard. For the the 22 blanks you could probably get away with a firing pin ground to look like a flat head screwdriver. As far as powder you wouldn’t necessarily need ball powder as you stated as it relies on filling the drill hole with water and since you can’t really compress water, it has to go somewhere.

I made up a bunch of different electric cartridges to test for cave rescue stuff. I can confirm that pretty much any smokeless powder will break rock if confined.

 

[Assembler]

I looked up the Boulder Blaster and found it appears the shells used .22 blanks like you use in a Ramset as their primers the company even referred to them as rimfire primers. Ramset blanks are easy to find at most any hardware store. Interesting stuff to think about. I wonder if that is something those Australians did as far as firearm law as they are pretty strict over there in that regard. I assume a shot shell with a 22 blank as a primer would need a special offset firing pin and wouldn’t be functional ammunition in a regular shotgun possibly skirting around ammunition sale restrictions.

Yes it is a rim-fire primer except some of the earliest models. The important factor is enough primer material to fire the powder load. One may be able to machine the primer pocket of a solid brass case to prime with other primers. I'm not a machinist however I'm getting a old Atlas 6" by 18" lathe together for this one.........lol.

 

[Assembler]

I made up a bunch of different electric cartridges to test for cave rescue stuff. I can confirm that pretty much any smokeless powder will break rock if confined.

Correct however one must take maximum pressures into the mix as a regular thin barrel shotgun will blow a break in ether the action area or the barrel itself.

 

[Assembler]

Correct however one must take maximum pressures into the mix as a regular thin barrel shotgun will blow a break in ether the action area or the barrel itself.

The fellow that I saw a picture of his cannon gun looked like the action end was around 2 1/2" -3" thick and maybe around 2" thick on the barrel. A regular thin shotgun is around only 1 1/8" thick on the barrel at the most to give you some idea of the pressures involved with this type of powder load. You do not want to be holding this or even very near this when it fires off.

Warning it is a very good idea to weigh this cannon down with some protection around it so that if it is to breach it will not injure anyone.

 

[Assembler]

The fellow that I saw a picture of his cannon gun looked like the action end was around 2 1/2" -3" thick and maybe around 2" thick on the barrel. A regular thin shotgun is around only 1 1/8" thick on the barrel at the most to give you some idea of the pressures involved with this type of powder load. You do not want to be holding this or even very near this when it fires off.

Warning it is a very good idea to weigh this cannon down with some protection around it so that if it is to breach it will not injure anyone.

By the way the fellow over seas showed a picture of what rock he is busting up in the ground and it looks very impressive. Just make sure you are following all of the safety rules as you go and you should not have any problems.

I may give the old Atlas lathe a go at machining thick sleeves to go over a thin cheep shotgun barrel. I will start with low test loads and work up the heavy loads watching for stress issues by measuring for stretch.

Any ideas here on this project?
Anyone know of good machinists sites to get tips online?
Thanks.

 

[Assembler]

By the way the fellow over seas showed a picture of what rock he is busting up in the ground and it looks very impressive. Just make sure you are following all of the safety rules as you go and you should not have any problems.

I may give the old Atlas lathe a go at machining thick sleeves to go over a thin cheep shotgun barrel. I will start with low test loads and work up the heavy loads watching for stress issues by measuring for stretch.

Any ideas here on this project?
Anyone know of good machinists sites to get tips online?
Thanks.

Anyone know of a good source of small boring bars and other lathe tooling?

 

[BlasterJ]

Correct however one must take maximum pressures into the mix as a regular thin barrel shotgun will blow a break in ether the action area or the barrel itself.

To be clear, the charges I was working with were stemmed into the rock with a clay/sand mixture or a heavy steel tamper, so there was no barrel to worry about. But I also have a manufacturer's license and bought electric match igniters from a fireworks supplier.

For the boulder buster, the barrel is completely contained inside the rock when set up and the head is massive (around 15lbs if I recall) to provide inertia. It requires around a 1.5" hole.

 

[Assembler]

To be clear, the charges I was working with were stemmed into the rock with a clay/sand mixture or a heavy steel tamper, so there was no barrel to worry about. But I also have a manufacturer's license and bought electric match igniters from a fireworks supplier.

For the boulder buster, the barrel is completely contained inside the rock when set up and the head is massive (around 15lbs if I recall) to provide inertia. It requires around a 1.5" hole.

There is still the receiver / action sticking out of the ground.
Why not have the entire cannon sticking out of the ground and just fill the hole with water.
There is no problem with 12 gauge shells as they have been used for at least 200 years or so.