light strike

Sighted in new Winchester. 50 rounds. Really nice.
On third mag, had one light strike. Could barely see dimple in primer.
Recycled and fired.
Any ideas how and why this occurred?
TIA

Maybe old cosmo in the bolt. One of mine would hardly fire and I had to dismantle the bolt to clean it out.

Joem,
Thanks. Bolt had been stripped, cleaned and properly lubed. That would have been my first thought also.

Chances are for that one shot the bolt was not all the way locked into battery. The carbine safety features prevented it from firing.

Scott