I am seeing an increase in the firearm background check system sometimes rejecting gun purchases, in error, based on adult and juvenile criminal cases from years ago. People should seriously consider getting certified copies NOW of any past cases other than simple traffic offenses, so they can prove the case would not result in loss of gun rights.
Bump-stocks became illegal nationwide as of March 26, 2019. No exceptions, no "grandfathering" in those already owned. The Supreme Court has declined to postpone that deadline. Owners are required to destroy them so that the bump-stock cannot later be made functional. Possession of a bump-stock is now a felony.
In Colorado, the weapons prohibitions for felons includes persons with a juvenile felony history. Juvenile adjudications can often be expunged, and should be expunged before any weapon possession.
A 2018 change in Colorado law gives some hope for reinstatement of eligibility for occupational licenses after criminal convictions, usually felonies, that normally would block such eligibility under a State statute or regulation.
If you have an old court or arrest record that needs to be cleared up, don't wait. The older the record gets, the more difficult it is to get the full record located and corrected.
In Colorado, pre-2017 juvenile cases are not automatically expunged. And any arrests after age 18 arising from a juvenile case is a public record. Petitioning to expunge juvenile records is often a good idea.