Shilen scribe mark meanings?

[BTSniper]

I thought I knew the meaning of all the scribe markings on the Savage prefit barrels from Shilen but can anyone tell me what "xx" means?

I ordered a stainless 20 practical "match" barrel from Jim at NSS. It was scribed 20 practical (obvious) 12T (12 twist, again obvious) probably S7 (for the savage contour I'm sure) and then xx was scribed as the last marking. I know if I had ordered a "Select Match" it would have been scribed S/M.

Anyone know what the "xx" means?

Thanks

BT

[strut64]

Call Shilen. They are helpful.