I wasn't sure whether to post this under technical or NFA but we'll start here. So I recently upgraded some parts on my SBR and I'm now receiving much more gas blowback than previously. I have a Sionics 11.5 standard barrel, Sionics gas block and gas tube with a SilencerCo SpecWar K attached via ASR flash hider. Here is my list of upgraded components:

BCM4 standard upper to Vltor MUR 1A
BCM bolt carrier to LMT enhanced carrier
BCM Mod4 to Geissele ACH

I don't believe it matters but I swapped from an A5H4 to A5H3 buffer and Colt FCG to Geissele SSA. I'm having difficulty understanding why this is happening, especially with the e-carrier. The blowback is the worst during the first few rounds and seems to dissipate through the remainder of the magazine. I will RTV the ACH after I can unpack after moving here in the next few weeks to see if that helps.

I'm interested to hear any thoughts or suggestions.