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.
Starting Form 1 for a 6.8 SPC on an AR with 16" barrel.
Tube is 8" long, 1.625" OD Titanium
Planning on standard Ks
I have had good success in 3 previous builds for .22LR, .223, .300BLK, using Aluminum, Stainless & Ti in that order. I have not included an elaborate blast chamber in any of these 3, rather just exaggerating the volume in the first section.
My machining skills are improving each build and I am wondering if it is critical that I incorporate a stainless liner in section 1 for blast chamber or if consensus is that I could get away with another large first chamber using only the single wall Ti & the Ti K baffle as first baffle? (maybe I should have included a voting button )
Still awaiting an original & riveting thought for signature line; stand by...........
)