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.
Just finished my micro 223 suppressor. Its 3.7" long x 2" diameter. I built it to fit the same muzzle brakes that I made for my compact 223 suppressor.
The body, mount/blast walls, and end cap are 4130. The baffles are 17-4 stainless.
I had to use a shallower cone to fit three baffles in the short space. This was the first time I tried leaving the spacer on the cone side like an M baffle instead of the traditional built in spacer on the cone baffle.
Micro on top, my 5" compact build and then a commercial 223 suppressor
Are the "circles' on the muzzle side plug welds? Doesn't look bad I think I might of tried to squeeze more cones in just my $0.02 maybe add one to fit inside the end cap? Hows it sound?
"A man is known by the silence he keeps. - Oliver Herford"
"Gunpowder, treason and plot. I see no reason why gunpowder, treason
Should ever be forgot..."
I press fitted and plug welded the mount in the tube before doing the full circumference weld at the base. The mount and blast chamber wall is all one piece so there are not separate spacers inside. The muzzle brake is 1.6" long (same as A2 flash hider) the first cone length is dictated by that.
There is a small 60 degree cone machined into the end cap, left as a shallow cone to keep the internal volume. The 5" long suppressor I built only had three baffles and was very quiet.
I don't really expect this one to be as quiet even though the internal volume is roughly the same thanks to the larger diameter. This is going to stay on my 7.5" to get the sound and concussion down to a reasonable level. When the ice melts I'll try it on a few different length ARs to see how it does
I finally got to try this one out today (we had our first child 4 weeks ago so time is scarce). I shot it on my 7.5" upper which is the loudest thing I have. It was slightly louder on it than my longer suppressor but was actually comfortable to shoot without hearing protection.
