I need help figuring out if this is normal. I just finished my AR9 build and when test firing it for the first time I noticed a pretty good about of sparks coming out of the ejection port. I couldn't find much info across the different forums I searched other than maybe it's just some of the remaining powder burning as the round finishes cycling? I just feel like there shouldn't be as much still burning as I'm seeing, at least not as consistent as I'm seeing it. Fired about 60-70 rounds total and everything functioned fine other than the sparks. I checked the cases and didn't see any bulging so I think the rounds are seating properly. Any advice?
Video link: https://www.youtube.com/watch?v=d51NN4YBrRE
Relevant build info (can post full build if needed):
Faxon 16" barrel
Faxon gen 2 9mm blowback full-mass BCG
Tubbs Precision AR-10 stainless steel buffer spring (.308 flatwire spring)
Blitzkrieg AR15 9mm HD hydraulic buffer
New Frontier Armory upper
