That's pretty fast for no autosear. We measured the time from the beginning of the bolt recoil to return to battery at 100 ms for a properly gassed gun using 3 dram, 1 1/8 ounce low brass. That doesn't include the time the shot travels down the barrel or lock time. The 3.42 time put you at 171 ms or about a 70 ms reaction time on the trigger less the two variables mentioned above.
Edited to correct ms times - that will teach me not to post data from memory instead of going back to the spreadsheet
