Looking at buying a BC Miruko sxs but the choke designations are a little weird. I thought Miruko used the same marking as Browning but this one has a barrell marked MOD and one marked IMP the IMP one is the right barrell. Is the right barrell not usually the tighter of the two chokes on a SXS? If so could this IMP mean IMP MOD? This could be a deal breaker for me. Thanks for any help>