Fix NICS Act of 2017 (Sec. 2) This bill amends the Brady Handgun Violence Prevention Act to require each federal agency and department, including a federal court, to: certify whether it has provided to the National Instant Criminal Background Check System (NICS) disqualifying records of persons prohibited from receiving or possessing a firearm, and establish and substantially comply with an implementation plan to maximize record submissions and verify their accuracy. (Sec. 3) The bill amends the NICS Improvement Amendments Act of 2007 to modify the NICS Act Record Improvement Program (NARIP). Specifically, it: establishes a domestic abuse and violence prevention initiative as a priority area for NARIP grant funding, and creates a funding preference for states that establish an implementation plan and use grant funds to upload felony conviction and domestic violence records. (Sec. 4) It amends the Crime Identification Technology Act of 1998 to modify the National Criminal History Improvement Program (NCHIP). Specifically, it: specifies that facilitating full participation in the NICS, as an allowable use of NCHIP grant funds, includes increasing efforts to pre-validate felony conviction and domestic violence records to expedite eligibility determinations; and permits the federal share of a grant to exceed 90% of program costs if a state complies with its implementation plan. (Sec. 5) This section amends the NICS Improvement Amendments Act of 2007 to: direct the Department of Justice (DOJ), in coordination with each state or tribal government, to establish an implementation plan, including benchmarks, to maximize the automation and submission of mental health and criminal history records to the NICS; require DOJ to conduct, and publish the results of, compliance determinations for state and tribal governments; give preference to certain discretionary grant applicants that substantially comply with an implementation plan; and require the NICS to notify law enforcement agencies when a firearm is transferred to a person who is subsequently determined to be prohibited from receiving or possessing a firearm. (Sec. 6) DOJ's Bureau of Justice Assistance must report to Congress on the use of bump stocks in the commission of crimes, including the number of instances and the types of firearms. (Sec. 7) The bill authorizes appropriations for FY2018-FY2022 to carry out activities under this bill.