Sentry 7 Set Screw Adjustable Gas Block - .450"

Solid gas block, Easy installation!

Love using this gas block! It's super low profile and fits under my STNGR HWK and VLCN handguards. The included allen wrench is long enough to adjust the gas settings with the handguard still attached (although this will vary with the handguard and gas system lengths). Installation was super easy on my Rosco Bloodline barrels, as all that was required was lining up the set screw with the barrel's dimple (pre-dimpled from the manufacturer). I did not use Locktite as the gas block heats up too much for it to hold reliably, and the screws are still tight after firing a couple hundred rounds. Looks very easy to take apart to service or clean if needed. The locking positions in the gas block are distinct enough to use repeatably, but a little mushier than I had hoped. All things considered, still a great product at a competitive price.

I purchased this SA7-450-SM gas block after experiencing blown primers and cycling issues in a 16" 5.56mm, mid-length barrel paired with an AR-15 bolt carrier. I judged the barrel gas hole was too large for my original GB7-450 gas block and H1 buffer in combination with the dwell length and BCG. After replacing the fixed gas block with this adjustable and swapping buffers, the carbine cycles flawlessly (with either an H2 or H3 buffer). I've bought a second SA7-450-SM for a 6.5 Grendel upper and will get a third for a 224 Valkyrie upper. The adjustments are excellent, allow for fine tuning and will be a bonus for suppression.

Running this block on my 6" 5.56 SBR. The gas block is fantastic and allows the user the adjust for all types of ammo suppressed or unsuppressed. If you have and SBR, I would highly recommend getting this gas block. Hands down the best adjuatable gas block on the market! The customer service is exceptional too!