So, I went digging in the CRS to see if there's a way for to refute the "Within 10 year" requirement and unfortunately, I believe I found the opposite.
Key excerpts from CRS 18-12-203:
On original issuance:
(1) Beginning May 17, 2003, except as otherwise provided in this section, a sheriff shall issue a permit to carry a concealed handgun to an applicant who:
(1) (h) Demonstrates competence with a handgun by submitting:
(1) (h) (VI) A training certificate from a handgun training class obtained within the ten years preceding submittal of the application.
On reissue:
(3) (a) The sheriff shall deny, revoke, or refuse to renew a permit if an applicant or a permittee fails to meet one of the criteria listed in subsection (1) of this section...
Note that (3) (a) specifies "shall deny", not "may deny".
Bummer.
My suggestion: If it's been more than 10 years, grab your .22 and find yourself a steel match*. Then bring a copy of the results with you wehen you renew to satisfy (1) (h) with:
(1) (h) (I) Evidence of experience with a firearm through participation in organized shooting competitions or current military service;
O2
*In steel matches, .22s start from the bench, not holstered so anyone and everyone can play. May I recommend
Hoser's Wednesday steel matches in Pueblo.