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.
I am better with a lathe and mill than with the pen. But I wanted some opinions of this design for a 7WSM / .308. OD is 1.5", overall length is 12.25". Full titanium build. Will most likely change the angle of the cone and shorten the space in between to ad another baffle. For the most part, can will be fully welded, no threading except for the barrel atachment. Getting ready to send in my form 1 and trying to nail down a design.
1st response: Barrel will be stepped down ahead of the bearing surface, giving about .050" clearance (enough?). I could try and figure out a way to make the blast baffle out of stainless. Would have to figure out how to hold it in place, since my original thought was to weld it in place and help setup the rest of the stack.
Thanks, Jerry
Last edited by 257speed on Sun Jan 11, 2009 11:51 pm, edited 2 times in total.
I think that the crud is going to buid up quickly onto the barrel of the over the barrel design, causing it to be hard to remove your slip fit end of your silencer. Titanium is not going to hold up well to the heat of the blast on the first baffle.
NFA shooters blow their load with only one pull of the trigger.
I have a similar design in progress for a 22LR with less baffles. In my project the "threaded attachment spacer" and (what I call) the "alignment end cap" are machined from a piece of solid aluminum bar so that there is an inner tube to the expansion chamber that fits over the barrel. The outer tube then slides over the "threaded attachment spacer" and meets the "alignment end cap" as per your design.
Since the "alignment end cap" is made in one piece with the "threaded attachment spacer" I think the "alignment end cap" can be used to screw the can into position on the thread. There will be no need to secure the "threaded attachment spacer" to the outer tube.
Because it is for the 22 my baffle system is much simpler so the projection beyond the end of the barrel is about 3 inches.
David Hineline wrote:I think that the crud is going to buid up quickly onto the barrel of the over the barrel design, causing it to be hard to remove your slip fit end of your silencer. Titanium is not going to hold up well to the heat of the blast on the first baffle.
Wow! We run titanium exhaust valves in engines that run WOT for three hours at 1450 degrees F. What is the gas temp at the muzzle of a typical rifle? Please educate me.
David Hineline wrote:I think that the crud is going to buid up quickly onto the barrel of the over the barrel design, causing it to be hard to remove your slip fit end of your silencer. Titanium is not going to hold up well to the heat of the blast on the first baffle.
Wow! We run titanium exhaust valves in engines that run WOT for three hours at 1450 degrees F. What is the gas temp at the muzzle of a typical rifle? Please educate me.
Barrels go red hot, moving towards orange or yellow, so that means the flash or source of heat has to be higher than that, I would say well into white hot from the looks of flash.
I appreciate everyone's input. Is the consensus that the titanium blast plate will or will not hold up? Again, this will be fired on a precision bolt gun, never semi or full.
David Hineline wrote:I think that the crud is going to buid up quickly onto the barrel of the over the barrel design, causing it to be hard to remove your slip fit end of your silencer. Titanium is not going to hold up well to the heat of the blast on the first baffle.
Now that I've made an 'over the barrel' can for a centerfire I don't think this is going to be an issue unless you go a *long* time between removal (and maybe not even then). My can is getting little more than soot on the barrel after 20-30 rounds - certainly nothing that would impede removing it. Situation is different if you were building a rimfire can, of course.
I'd make the first baffle out of stainless - I don't know about Titanium, it might work, but I have confidence that stainless would work in a non-FA can.
What I've learned about using titanium (GR5) in muzzle brakes for IPSC rifles I could say that it wins all stainless and tool steels hands down what comes to erosion.
For instance stainless brake was worn out 50% of the material with 6000 round .223 with 16" barrel but GR5 titanium less than 30% with double the ammo. With .308 and 7.62x39 even stainless did very well and there were no need for using titanium. And IPSC is hell for a muzzle brake.
257speed wrote:I appreciate everyone's input. Is the consensus that the titanium blast plate will or will not hold up? Again, this will be fired on a precision bolt gun, never semi or full.
I would say Ti will be fine for your blast baffle on a bolt gun. The grade 5 Ti muzzle brake and blast baffle in my .50 bmg can show no signs of wear or erosion yet.
GeneT wrote:Interesting! That's win-win if it's tougher and lighter. Are you making your own brake, or are these commercial brakes?
GsT
DIY. Otherwise it would be hard to compare wide selection of materials with same brake design. (Who would find it commercially profitable to spend a lot time slowly milling a muzzle brake that spits (terrifying) white sparks with short barrel and trying to catch recoil and flames with hi-speed camera just for sake of difference about 0.01 second in keeping sight picture on target? )
...Found a better pair of pics. Desing is different because of the dimension rules in standard:
Testing stainless SharkBrake:
GeneT wrote:Very cool. I've been meaning to try a shark-style brake on my AR's for a while now. How'd you like it for performance?
Give up on the camera - your shot timer and the target should tell you all that's important...
GsT
I guess we're starting to drift towards OT but:
True, timer is the final word, but Casio EX-F1 can give hints about balanced chamber holes better than Aimpoint dot trail against the dark and to see if recoil is up'n'down or straight back. Stable back and forth rifle is better than down pushing when you might get into a situation where rifle is upside down or tilted on wrong shoulder.
This season I had SharkBrake in open too. That should tell enough. A slight modification in design can be seen as well as temporary extended sight radius. I must give you a warning though. It blows dust on low bipods but less than Miculec. For dust problem I used this, but it was too dominating in mass at the end of 18" barrel with targets far apart from each others.
...Reason for camera is that I like the flaming brake pics! Q: Which one is wasting more gases forward?
David Hineline wrote:I think that the crud is going to buid up quickly onto the barrel of the over the barrel design, causing it to be hard to remove your slip fit end of your silencer. Titanium is not going to hold up well to the heat of the blast on the first baffle.
Wow! We run titanium exhaust valves in engines that run WOT for three hours at 1450 degrees F. What is the gas temp at the muzzle of a typical rifle? Please educate me.
Barrels go red hot, moving towards orange or yellow, so that means the flash or source of heat has to be higher than that, I would say well into white hot from the looks of flash.
Please educate me. 
Q: Which one is wasting more gases forward? 
