SAMPLES CONSISTING OF 3 BULLETS WERE SENT TO 123 LABORATORIES, TOGETHER WITH INSTRUCTIONS TO USE NORMAL LABORATORY PROCEDURES TO DETERMINE WHICH, IF ANY, OF THE 3 PROJECTILES WERE FIRED FROM THE SAME GUN. OF THE 88 RESPONDING LABORATORIES, 57 CORRECTLY IDENTIFIED THE 2 BULLETS THAT ACTUALLY HAD BEEN FIRED FROM THE SAME GUN, 18 CORRECTLY IDENTIFIED THE 2 BULLETS FROM THE SAME GUN BUT WERE INCONCLUSIVE ABOUT THE THIRD BULLET, 5 CONCLUDED THAT ALL 3 BULLETS HAD BEEN FIRED FROM THE SAME GUN, 3 SAID THAT NONE OF THE BULLETS CAME FROM THE SAME GUN, AND 5 WERE INCONCLUSIVE IN THEIR FINDINGS. SUMMARY DATA AND BREAKDOWNS OF RESPONSES FROM INDIVIDUAL LABORATORIES ARE PRESENTED IN TABLES. AN EXPLANATION OF SURVEY METHODS AND A COPY OF THE SURVEY INSTRUMENT ARE PROVIDED. OTHER PROFICIENCY TESTS INVOLVING FIREARMS EVIDENCE ARE REPORTED IN NCJ-47523 AND 47528. TESTS INVOLVING OTHER SUBSTANCES ARE REPORTED IN NCJ-47522, 47524-47527, AND 47529-47541. (LKM)