Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.
This exclamation is most famously attributed to the ancient Greek scholar Archimedes; he reportedly proclaimed "Eureka!" when he stepped into a bath and noticed that the water level rose — he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. This meant that the volume of irregular objects could be measured with precision,
Do elaborate sir...
I'm kidding.
I just use the estimate of a cylinder that size, but displacement would be pretty dang precise.
"I notice that everybody that is pro-abortion already has been born."
--Ronald Reagan
This exclamation is most famously attributed to the ancient Greek scholar Archimedes; he reportedly proclaimed "Eureka!" when he stepped into a bath and noticed that the water level rose — he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. This meant that the volume of irregular objects could be measured with precision,
Do elaborate sir...
I'm kidding.
I just use the estimate of a cylinder that size, but displacement would be pretty dang precise.
Fill brass case with water, empty all the water into probe tube or other volume-measuring device.
"There are no stupid questions, only stupid people". -MAJ MALFUNCTION
This exclamation is most famously attributed to the ancient Greek scholar Archimedes; he reportedly proclaimed "Eureka!" when he stepped into a bath and noticed that the water level rose — he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. This meant that the volume of irregular objects could be measured with precision,
Do elaborate sir...
I'm kidding.
I just use the estimate of a cylinder that size, but displacement would be pretty dang precise.
Fill brass case with water, empty all the water into probe tube or other volume-measuring device.
And he then would know the internal volume of the case
but he want to know the volume of the chamber
To the op ,, why i have to ask , do you need the volume of the chamber
New to the forum so sorry if this is dredging up a dead post but this is a good post, interesting subject and I thought I'd throw my $0.02 in...
Bowen1911 wrote:este, looking in my strength of materials book, the tensile stress from the hoop stress doesn't increase linearly with relation to the wall thickness for cylinders.
granted it is near linear due to it being thin walled. ----- hoop stress = pressure* average radius/ thickness
the difference in radius is less than 10 percent, so the book says to use the thin walled formula.
Sounds good but (I might be preaching to the choir) imo if there is ever a question about which eqn to use (especially at dangerous psi), always use the thick walled eqn as opposed to the thin. The thin walled eqn makes assumptions while the thick does not. Better safe than sorry. This can also be handy during the design stage when dimensions are not yet set in stone.
Droopy Almond
You were supposed to be this colossus, you were this great legendary thing, and yet he gains!!
I started doing calculations for a .223 Ar-15 suppressor yesterday and ended up with 21,000 PSI entering the suppressor. That is with a safety factor of 1.5. My question is, is that value about right, or too low?
Also, I am doing flow simulations in solidworks, which i know are not that accurate, but was wondering what input temperatures to put. I currently put 21,000 psi and 200 degrees F for input and atmosphere pressure and 100 degrees F out. Any ideas as to the pressure out and the temps i would be dealing with?
Has anyone ever seen a comparison study on how different loads affect frp? After reading this thread and Paul's thread on frp I got to thinking (always a dangerous proposition).
Someone already probably had this idea but I was thinking that, just as you can adjust blast baffle distance to change frp, form 1 builders might be able to reverse engineer a load to work with the baffle distance they are stuck with in their one time only build if they had some useful data.
Conversely, if anyone has already made a basic study of the relationship between muzzle pressure and blast baffle distance, it might give a better starting point for design.
I'm sure that some of the commercial makers have done it with flow simulations, and the research would have to be expensive due to the various types of baffle designs and calibers. Probably considered trade secrets.
maxxwell86 wrote:Has anyone ever seen a comparison study on how different loads affect frp? After reading this thread and Paul's thread on frp I got to thinking (always a dangerous proposition).
Someone already probably had this idea but I was thinking that, just as you can adjust blast baffle distance to change frp, form 1 builders might be able to reverse engineer a load to work with the baffle distance they are stuck with in their one time only build if they had some useful data.
Conversely, if anyone has already made a basic study of the relationship between muzzle pressure and blast baffle distance, it might give a better starting point for design.
I'm sure that some of the commercial makers have done it with flow simulations, and the research would have to be expensive due to the various types of baffle designs and calibers. Probably considered trade secrets.
You do raise an interesting idea. How difficult would it be for a can maker to have the first baffle threaded
so that the user could screw it in or out to tune it ... like the old carbs ... for performance.
You do raise an interesting idea. How difficult would it be for a can maker to have the first baffle threaded
so that the user could screw it in or out to tune it ... like the old carbs ... for performance.
Threaded blast baffle...now that's an idea! Solves the whole form 1 issue of "ya can't change it once it's done".
Maybe thread the entire tube and make all the baffles adjustable? One the other hand, maybe not. We'd have to have someone open a shop to correct all the problems we created by adjusting them.
I would think you would have to have it mounted in a module or something
so that you could adjust it's spacing and not disturb the rest of the stack.
If it was just inside the threaded tube, it would take awhile until the carbon buildup held it.
Back in the day when we could play and changed things around. I recall my first .22 lr can had
a 1" blast spacer, 1/2" spacers between the baffles and a 3/4" exit spacer.
I played around with the placement of those and found the 1/2" blast spacer gave the best results with frp.
Maybe if we all built with a series of 1/2" spacers (and maybe a 1/4 & 3/4 thrown in for good measure) between all the baffles we could adjust the internals and not mess with threading the blast baffle.
There are multiple blast chamber suppressors as well as logarithmic baffle layouts out there so it must be useful in some cases.
Just swap the order of the parts around, no new parts added just re-oriented. No ATF violation, better performance.
True modularity and load/platform adjustable. A few more parting cuts on the lathe but well worth the effort.