New SBR Build with Geissele MK8 Rail

So new SBR build has been completed and tested at the range.

Here’s my build specs:

  • PSA Stripped Lower (engraved for SBR Form 1)
  • Aero Precision Upper
  • Aero Precision 10.5″ Barrel
  • Magpul SLK stock and grip
  • Trijicon MRO with LaRue QD Mount
  • Geissele MK8 Rail 9″
  • AAC 51T Mount
  • Using a AAC 7.62SDN can currently
  • Streamlight Rail-Mount HLX

So function was great, even suppressed. Things I noticed however:

  1. Wow, the rail gets HOT after 20 to 30 rounds. Hot enough I could not hold it. After researching it, it seems these slim-lined rails are known for that. Plus, I wasn’t using gloves on a 95+ degree day.
    1. I’ll probably install the larger plastic MLOK guards to help with this heat issue.
  2. This was to be expected, but was getting some gas blowback after heavy sustained fire. I’ll need to install an adjustable gas block to contain this. Moreover, I noticed ejection at 2 o’clock when running suppressed. I want this down slightly to 3 o’clock.

Love SBR’s and after some slight tweaks, this will be my go-to rifle!