BY MEGAN SCHRADER megan.schrader@gazette.com -DENVER - For almost two years Colorado has required those buying guns from private individuals to pass background checks, and the effectiveness of the checks has been a source of constant debate in the Capitol.The debate was sparked again on Monday as Republican lawmakers tried to curtail several restrictions on gun owners with seven bills, including the repeal of background checks for private sales - which failed committee on a 7-4 vote - and ending with an attempted repeal of the requirement for background checks on those who have concealed handgun permits, which was rejected on a 7-2 vote.