GBF (Gas Block Forward Controls) comes in two gas journal sizes, 0.625 and 0.750 done the FCD way: meticulously designed and machined, with thoughtful features throughout.
Machined from heat treated 4140 bar stock, GBF is manganese phosphate coated, GBF holds rather tight tolerances to squeeze every bit of tight seal we can from the design. GBF's gas tube hole can be described as semi blind hole, in that it has an access port just big enough to allow a 3/32 punch to go through. This feature was suggested by the late Semper Paratus Arms owner and operator, Will Larson, its purpose is to minimize the gas tube hole as much as possible, while providing a means for users to use a punch to dislodge an recalcitrant gas tube that's been fixed in place by carbon.
Another useful feature is the bosses on both sides of the GBF to give gunsmiths an easy reference point to pin the GBF to the barrel. Both 5/32x5/8, and 1/8x5/8 pins can be used to pin the GBF to the barrel. Its set screws are 0.450 apart, which is compatible with one of the set screw spacing options on the popular SLR Rifleworks's 750 dimpling jig.
GBF isn't meant to be a light weight gas block, we prefer strength and dependability over any ever changing fad. GBF's sleek appearance is the result of removing material that adds weight but doesn't contribute to the strength and reliability.
A gas tube pin, two knurled set screws are included (3/32 wrench is required.) A 5/32x5/8, and 1/8x5/8 coiled pin can be added as a no cost option. Rocksett is recommended for the set screws.
Set screws spacing: 0.450"
Torque value for knurled set screws: 25inch·lb.
Weight: 1.58 oz.
Proudly designed and made in the USA.
