Adjustable Gas Block Adjustment

STOP!!

YOU MUST ENSURE YOUR FIREARM IS FULLY UNLOADED AND PROVED SAFE BEFORE USING!!

PROVE
POINT THE FIREARM IN THE SAFEST AVAILABLE DIRECTION.
REMOVE ALL AMMUNITION.

OBSERVE THE CHAMBER.
VERIFY THE FEEDING PATH.
EXAMINE THE BORE.

ONCE SAFE, YOU MAY PROCEED TO THE NEXT STEP.


WHAT DOES AN ADJUSTABLE GAS BLOCK DO?
A NON-ADJUSTABLE GAS BLOCK SIMPLY DIRECTS GAS FROM THE BARREL, UP THROUGH THE GAS BLOCK AND BACK TO THE BOLT CARRIER GAS KEY THROUGH THE GAS TUBE. THIS GAS PRESSURE UNLOCKS THE CHAMBER AFTER THE ROUND IS FIRED AND CYCLES THE BOLT AGAIN. WITHOUT THIS SYSTEM, YOUR GAS OPERATED RIFLE WOULD NOT CYCLE IN A SEMI-AUTOMATIC FASHION. NON-ADJUSTABLE GAS BLOCKS HAVE A FIXED GAS PORT SIZE, AND CANNOT BE ADJUSTED TO COMPENSATE THE AMOUNT OF GAS VOLUME.


ADJUST THE GAS BLOCK TO PERFORM OPTIMALLY WITH YOUR SPECIFIC AMMUNITION LOAD.


YOU CAN TURN YOUR SEMI-AUTOMATIC RIFLE INTO A STRAIGHT PULL (NON-SEMI-AUTOMATIC) BY ADJUSTING GAS BLOCK TO FULLY CLOSED POSITION!


HOW DO I KNOW IF MY FIREARM IS CYCLING PROPERLY OR NOT?
TO FIX SHORT STROKING ISSUES, YOU SHOULD ADD MORE GAS VOLUME.


TUNING A RIFLE ISN'T JUST ABOUT GAS VOLUME! THE BUFFER WEIGHT IS VERY IMPORTANT TOO.


TOO LIGHT OF A WEIGHT ALSO MEANS THE BOLT WILL BE TRAVELING REARWARD AT A HIGHER VELOCITY, AND THE CYCLE WILL BE MUCH FASTER. IF THE CYCLING TIME IS TOO FAST, THE LAST ROUND BOLT HOLD OPEN FEATURE MAY NOT HAVE TO ENGAGE. TO CORRECT THIS, SIMPLY ADD MORE MASS, WHICH WILL SLOW DOWN THE CYCLING RATE AND GIVE THE BOLT CATCH TIME TO ENGAGE. IF THE FIRING BOLT IS CYCLING TOO FAST IT CAN CAUSE ADDED STRAIN AND DAMAGE TO THE BUFFER WEIGHT AND THE BUFFER TUBE.


RELOADING YOUR OWN AMMUNITION CAN BE DANGEROUS. SIMILARILY, ADJUSTING YOUR BUFFER WEIGHTS CAN ALSO BE DANGEROUS AND CAUSE NEGITIVE EFFECTS. ENSURE YOU KNOW WHAT YOU ARE DOING AND VERIFY YOUR CHANGES PRIOR TO LIVE FIRING! IF BUFFER WEIGHT IS TOO LOW FOR THE CALIBER YOU ARE SHOOTING DEATH, DAMAGE OR INJURY MAY OCCUR!


DURING THE REARWARD CYCLING, IT EXTRACTS AND EJECTS THE SPENT CASING, THE SAME WAY AS A BLOW-BACK SYSTEM WOULD.


THE BIGGEST DIFFERENCE TO BUFFER WEIGHTS IN A DIRECT IMPINGEMENT SYSTEM IS THAT THE BOLT IS LOCKED INTO THE CHAMBER DURING THE INTENSE FIRING SEQUENCE. DUE TO THIS "LOCKED IN" NATURE, ONCE THE GAS PRESSURE COMES THROUGH THE GAS TUBE AND PUSHES ON THE BOLT CARRIER TO RELEASE IT, MUCH OF THE FIRING FORCE HAS ALREADY DISSIPATED. BECAUSE OF THIS, THE BUFFER WEIGHT CAN BE SIGNIFICANTLY LIGHTER THAN THAT OF A BLOW-BACK.


THE BUFFER WEIGHT CAN HELP ABSORB SOME OF THE FELT RECOIL. THIS PROVIDES A SMOOTHER CYCLE OF THE BOLT GOING BACK AND FORTH, AND CREATES A BETTER SHOOTING EXPERIENCE WITH FASTER FOLLOW-UP SHOTS. HEAVIER BUFFERS ALSO HELP REDUCE WEAR AND TEAR ON YOUR FIREARM.


TYPICALLY A 5.56 RIFLE WOULD HAVE A BUFFER WEIGHT OF AROUND 3.0 OZ
ADJUSTING THE WEIGHT TO A HEAVIER BUFFER OF 3.8 OZ IS 25% HEAVIER AND REDUCES PERCEIVED FELT RECOIL AND REDUCES WEAR ON YOUR FIREARM.


THE HEAVIER THE BUFFER WEIGHT IS, THE SLOWER THE BOLT CARRIER TRAVELS REARWARD
REDUCING THE PERCEIVED RECOIL, HOWEVER THE HEAVIER WEIGHT RETURNS THE BOLT INTO BATTERY FASTER WHICH CAN POTENTIALLY CAUSE THE BOLT CATCH TO ENGAGE IN THE WRONG PLACE OR CAUSE FAILURE TO FEEDS AND STOVE PIPING. FIND THE HAPPY MEDIUM BETWEEN BUFFER WEIGHT AND GAS VOLUME BY USING BOTH ADJUSTABLE SYSTEMS.


HAVING AN ADJUSTABLE GAS BLOCK ON A DIRECT IMPINGEMENT FIRING STYLE ALLOWS YOU TO ALLOW TUNE THE AMOUNT OF GAS PRESSURE PUSHING ON THE FIRING BOLT. YOU SHOULD AJUST THE GAS PRESSURE TO BE AS LOW AS POSSIBLE, WHILE STILL ENSURING THE FIREARM CYCLES PROPERLY BETWEEN SHOTS.


!! WARNING: PISTOL AND RIFLE BUFFERS ARE NOT INTERCHANGEABLE
STANDARD BUFFER WEIGHTS:
9x19MM REQUIRES 8OZ BUFFER WEIGHT
5.56 NATO REQUIRES 3.8OZ BUFFER WEIGHT


TOOLS REQUIRED:
#4-40 SET SCREWS (SIDE AND TOP) 1/20 INCH HEX ALLEN KEY [0.050 INCH]
ADJUSTABLE GAS SCREW 5/64 INCH HEX ALLEN KEY [0.078 INCH]


THE ADJUSTABLE GAS BLOCK HAS (2) TWO SET SCREWS.
 
THE SET SCREW LOCATED ON THE RIGHT HAND SIDE IS THE LOCKING SET SCREW WHILE THE TOP ONE ADJUSTS THE SPRING PRESSURE WHICH PUSHES THE BALL BEARING INTO THE ADJUSTMENT SCREW DETENTS.

 GAS BLOCK INTERNAL LEFT

NOTE: IF YOU ARE NOT HEARING OR FEELING TACTILE CLICKS:
LOOSEN THE SIDE LOCKING SETSCREW (COUNTER CLOCKWISE) THEN TIGHTEN THE TOP SETSCREW A LITTLE (CLOCKWISE).

TEST AND REPEAT UNTIL AUDIBLE AND TACTILE FEEL OCCURS WHEN ADJUSTING THE MAIN ADJUSTMENT SCREW.

TIGHTEN SIDE LOCKING SET SCREW.



IF SEMI-PERMANENT GAS BLOCK POSITION IS REQUIRED, LOOSEN SIDE LOCKING SET SCREW AND TIGHTEN TOP SCREW UNTIL NO MOMENT IS POSSIBLE WITH ADJUSTMENT SCREW. TIGHTEN SIDE LOCKNG SCREW.

 

FOR EVEN FURTHER REDUNDANCY, BLUE OR PURPLE LOCTITE MAY BE ADDED.
!! NEVER USE RED LOCTITE


TEST IF FIREARM IS CYCLING PROPERLY
LOAD 1 MAGAZINE WITH (2) RDS. CHAMBER AND FIRE FIRST ROUND.


IF BOLT DOES NOT CYCLE REARWARD ENOUGH TO PICK UP AND LOAD THE SECOND ROUND IN THE CHAMBER, THEN GAS PRESSURE IS TOO LOW. ADJUST THE GAS BLOCK (2) CLICKS HIGHER. TURNING THE GAS ADJUSTMENT SCREW COUNTER CLOCKWISE ALLOWS MORE GAS TO FLOW TO THE BOLT CARRIER. TEST AND CONTINUE TO ADJUST IN SMALL INCREMENTS UNTIL THE RIFLE RELIABLY PICKS UP AND FIRES THE SECOND ROUND. BOLT CATCH SHOULD ENGAGE WHEN MAGAZINE IS EMPTY.
GAS ADJUSTMENT
IF BOLT CATCH IS NOT ENGAGING AFTER MAGAZINE IS EMPTY
MOST COMMON ERROR IS BOLT IS CYCLING TOO FAST. DIAL GAS BLOCK DOWN SLIGHTLY TO DECREASE BOLT SPEED BY TURNING THE GAS ADJUSTMENT SCREW CLOCKWISE.

Lockhart Tactical
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