Re: How's a can help accuracy???
Some people have these problems with all kinds of cans, but the accuracy getting worse is generally related to the silencer weighing too much, or the silencer having a design flaw.
AAC silencers for rifles involve about 10 full circumferential welds in stainless steel which is known for a tendancy to warp when welded, and then if stresses are not relieved when heated as well. So the first round might shoot true and the third round may fly if the silencer was not properly heat treat stress relieved, post welding, prior to EDM. I've talked to one person who mentioned the same wandering group inside 3 rounds with a 7.62SD. He claimed to have tested it and found it to warp when heated. Perhaps shoot it, check tighten it, wait one minute and shoot it again repeat three times and see if this changes anything.
7.62SD's also have a 18? tooth mount which is known to pop loose in a lot of cases by a small amount, allowing play in the system even if it's very slight play. The ratchet is not timed to the spring detent locking mechanism and in relation to the threads on the barrel and flash hider. So you may be able to find a better mount if that is your problem through trial and error. AAC added a second (probably slightly off time) spring detent retainer to the later models, so I believe that splits the difference and makes the problem 1/2 as likely to occur, or makes you twice as likely to be able to find a satisfactory mount.
So you can see narrowing the problem to a source is tough. It could be stress relieving, or mounting, or weight, or even eccentricity and tightness combined of the blast baffle aperture.
Ops Inc makes silencers thast feature taper/collar conventional 60degree metric thread mounting (rock solid and even tensions the barrel improving rigidity), have symetrical baffle systems, and they are properly stress relieved post welding, although not EDM bored, they generally exhibit a tendancy to improve host weapon accuracy when employed, and minimally shift POI when installed on properly threaded barrels. There are only 2-4 sources in the US who do proper thread work that I know of. I trust ADCO firearms. They do really good work and they are really nice people to work with.
Surefire is similar to Ops in that regard.
Making silencers without flaws is tough. Most companies don't do it. Ops stuff is heavy. But that fault is a lot easier recieved than a lot of others esspecially to the precision rifle crowd.
Surefire stuff I've heard is loud, Ops 30cal stuff is louder than AAC but deffinitely OK. The Gemtech Sandstorm probably sounds very close to Ops (possibly very slightly quieter I haven't seen a test) and seems like a really good product if it lives up to gemtech claims of not impacting balistics negatively. I held one in Idaho at Gemtech last winter just before the shot show, and it seemed incredible in my hands.
I made a small run of .308 silencers that weigh 19 ounces and group ~5/8" (5RDs HSM118LR @ 100yards) on my FNSPR, but they metered 141DB (over the hearing safe threshold) with a higher FRP so there's the flaw in my design. Sound. It sounds good to me, but the meters are industry standard testing and my right ear is pretty damaged from military service.
