FMJ: All standard chome lined Bushmaster barrels have 1:9 twist rate. Its a special order (or overrun) that they would have anything else. The 'NM' barrel is an HBAR, the A2/"Govt profile" barrel (I see no 'cuts', the barrel is just PROPERLY profiled down between the chamber and front sight).
The A2 barrels are only available in a pre-ban form. HBARS can be had in either pre or post ban form. If you want a post-ban A2 than contact Gunsmoke Enterprises (they conver the A2s to post-ban) or Kurt's Kustom (he can turn down the HBAR to an A2).