Which part?
ID bore to back flat of adapter where it will seat to barrel shoulder not tram?
ID bore to threads  not concentric  themself to center line,  or canted threading to ID bore  all together instead.
Problem OD to ID with either threads or back flat as the tram point?
Or just threads so over size, they are joke to begin with, or back ID of channel not releived in a fashion that is barrel shoulder bottom of surface is not back squared, will cause adapter to cant before it can fully mate with barrel shoulder?

Also, are you sure this is a real surefire produced adapter, and not some know off clone.

Simply, don't need precise cad drawing, but a quick drawing of what is not running tram/concentric to begin with, would help to get a better under standing of what is not running true itself.  

Also, might want to give surefire a call, to verify it is one of theirs, and if it is, pretty sure they will send you are replacement on the spot, as well as issue a call tag to get the old one back.  Hence if they do have bad ones going out that QC did not catch, then any problems that they are causing to suppressors, would make the sole replacement costs of any destroyed suppressor fall back in their laps to replace as well.

Interesting issue.

I don't remember any of my Fast attach Wardens being a sloppy fit. Rock solid ?... not bolt and nut tight... but certainly not like your sounds like.
That said, I haven't been able to bring myself to pony up for the SFA2.

As a matter of fact, they were a far better fit, then any of the other brands I tried at the time. ( Lantac, a little to loose for me and my precision oriented preferences  .....Griffin Armament ,very,very dependent on the "A2" back circular cuts being squared off in the bottom of the valley, .... Frefrans, heavy danged thing, also fit the Strike Industries similar muzzle devices  )

I don't know if I can help with measurements.. but I can sure try.

IM me.