How difficult is it to replace a gas piston?

[alduro 0]

Has anyone here got an idea as to where I can find instructions on how to do this? How hard is it? Is the gas piston "pinned" in place? Do you knock it out with a punch? Thanks

[Tengu 0]

Here are the complete instructions for replacing the gas piston from the Red Star Arms website.

 

Follow these steps and install your RSA gas piston like a PRO!

 

GAS PISTON INSTALLATION INSTRUCTIONS

 

1.INSURE THE RIFLE IS UNLOADED AND REMOVE THE BOLT CARRIER ASSEMBLY FROM THE RIFLE.

 

2. REMOVE THE BOLT FROM THE CARRIER.

 

3. LOCATE THE 3MM DIAMETER CROSS-PIN (THE PIN SIZE MAY VARY BY COUNTRY OF ORIGIN) THAT RETAINS THE GAS PISTON TO THE CARRIER. IT MAY BE NECESSARY TO REMOVE THE FINISH FROM THE CARRIER IN ORDER TO LOCATE THE CROSS-PIN ENTRANCE AND EXIT HOLES IN THE CARRIER.

 

4. USE A NAIL SET OR DRIFTPUNCH TO START THE CROSS PIN MOVING AND A DRIFT PIN PUNCH TO DRIVE THE PIN THRU THE HOLE. IF EXCESSIVE FORCE IS REQUIRED TO DRIVE THE CROSS-PIN OR IF THE CROSS-PIN REFUSES TO MOVE, CENTERPUNCH ONE END OF THE CROSS-PIN AND USE A 3MM DRILL BIT TO DRILL .10" DEEP INTO THE CROSS-PIN. DRIVE THE CROSS-PIN OUT FROM THE SIDE YOU HAVE DRILLED.

 

NOTE: THE CROSS-PINS ARE OFTEN PEINED INTO COUNTERSUNK AREAS ON THE CARRIER. WHEN DRIVING THE CROSS PIN OUT IT IS NECESSARY TO DISPLACE THIS METAL BEFORE THE PIN WILL MOVE.

 

5. CHUCK A 3MM DRILL BIT INTO A DRILL PRESS AND INSERT THE BIT THRU BOTH HOLES IN THE BOLT CARRIER WITH THE BOLT CARRIER HELD LOOSELY IN A DRILL VISE. USING THE DRILL BIT TO POSITION THE BOLT CARRIER, TIGHTEN THE DRILL PRESS VICE SECURELY AGAINST THE BOLT CARRIER.

 

6. THREAD THE RED STAR ARMS GAS PISTON INTO THE CARRIER. IT SHOULD SCREW IN USING ONLY THE HAND. A PAIR OF PLIERS, PADDED WITH A THIN RUBBER SHEET, MAY BE REQUIRED. IN CASES IN WHICH THE FEMALE THREAD OF THE CARRIER HAS BEEN DAMAGED BY THE REMOVAL OF THE CROSS-PIN A 12MM X 1.25MM TAP SHOULD BE USED TO CHASE THE THREADS.

 

7. DRILL THRU THE GAS PISTON USING THE 3MM DRILL BIT ON THE SAME LOCATION AS THE TWO 3MM HOLES IN THE BOLT CARRIER.

 

8. INSERT A NEW 3MM CROSS-PIN INTO THE HOLE. THE CROSS PIN SHOULD BE LONGER THAN THE HOLE IS DEEP, AND EXCESS STOCK SHOULD BE POSITIONED EQUALLY ON BOTH SIDES OF THE BOLT CARRIER. USE A HAMMER AND PUNCH TO PEIN THE ENDS OF THE CROSS-PIN INTO THE COUNTERSINKS ON BOTH SIDES OF THE BOLT CARRIER HOLE. DRESS THE ENDS OF THE CROSS-PIN FLUSH WITH THE SURFACE OF THE BOLT CARRIER.

Edited April 24, 2004 by Tengu

[mrapathy2000 0]

I have read reports of cracked bolt carriers after this mod. though end result was EAA made good in replacing the bolt carrier. in another situation someone absolutely had to have matching serial numbers so he was able to send his rifle in for a complete replacement. EAA was kind since rifle was modded.

 

believe the ak74 piston is the same length as stock piston, though ak47 will work enough tolerance built in to accomidate it.