How do you complete a challenge multiple times?

Question

Right now, I've completed the "N7 Valiant Use" once. Here's an excerpt from the N7 HQ site:

N7 Valiant Use Earn
140000 Points Using the N7 Valiant 
Current progress: 140000/140000
Challenge points: 10
Times Completed: 1

If I earn more points using the N7 Valiant, the current progress doesn't change, so how would I ever get to complete this challenge again? Would I need to finish the Sniper Rifle Mastery challenge before the progress for the N7 Valiant resets?

Answer 1

Silver metal challenges like "N7 Valiant Use" reset once you complete the gold metal challenge that it's listed under. So in the case of "N7 Valiant Use", once you complete Sniper Rifle Mastery, "N7 Valiant Use" will reset.

Note: I've tested this with Tech Mastery. Among other silver metal challenges, I completed "Overload Use", then once I got the Tech Mastery gold metal challenge, all the silver metal challenges reset to 0 and so did the Tech Mastery. But for every one that I completed, it now shows as "Times Completed:1". Silver metals that I did not get under Tech Mastery, like "Tech Armor Use" remain at "Times Completed:0".

Answer 2

Challenges appear to be single shots. Once achieved they are done with. This is implied (in my opinion) by the multi-level challenges that appear in some places. They provide you with points for one tier of points, then again for more points, then again for higher.

If they could be repeated these multi-level achievements would appear to be somewhat self defeating.