I recently purchased a 6.8 SPC II upper from AR 15 parts.com. When I received the upper, stamped on the barrel was only 6.8 SPC with 1:11 twist. I emailed them asking if they sent me the under powered regular SPC by mistake. They replied that it is SPC II as advertised. I've started seasoning the barrel with just a few rounds of Hornady Black and so far I really like it. In just very cautious of actually putting SPC II rounds through it when I get some even though the company said it was spec II. Any thoughts on this issue? Please feel free to share any info you may have.