US Secret Service recently announced they are looking for a new rifle, and there are some explanations posted.
-the gun needs to have service life of 20,000 rounds, with requirements for accuracy and velocity.
-accuracy will be checked at 10,000-15,000 and 20,000 rounds.
-bore and gas port will be monitored through out the testing
-a two person team will test the rifle, one shooting and one loading magazine. First 4 magazines will be shot in semi-auto, the last will be in 3 to 4 round burst in full-auto mode. No mag dump.