The "light primer strikes" are from the firing pin's forward momentum when the BGC is slammed into battery, normal. Only one way to know if it's a headspacing issue, and that's to check the headspace. Gauges are relatively cheap. I have so little faith in people these day, I factor the tooling into a build.
Before I bought my HS gauges, ask the local GS how much to check HS. $50. I ask how much if I brought the bare barrel and bare bolt (takes barely 5 minutes to check) $50 and he tries to BS me saying "they need to be installed in the upper because it changes when you install the barrel into the upper". I get it. We all gotta eat but don't try to BS me. I'm BS proof.