View Full Version : Gas leakage question on a L1A1

June 28, 2007, 22:33
A shooter sold me a L1A1 that he could never get to operate properly. I bought the rifle for almost nothing and noticed right off the bat that the barrel timing was off. I re-timed the barrel. The gas piston was bent and binding as you twisted the piston in the gas tube. I replaced the gas piston. The piston will fall freely throught the gas block,tube,guide. When I fired a few test rounds, the action would only function on " 0 " setting ( fully closed ) and not lock the bolt back. The fired casing did eject, but only for a foot or so.
I have ordered a new complete gas block, recoil spring and gas tube.
Have I covered my bases?
Thanks for any imformation.

June 28, 2007, 23:56
It isn't likely you'll need to replace the gas block. The tube is usually the problem, they can get pinched at the end and bind the piston, they get the threads stripped, etc. Sometimes the threads in the block might need chased.

June 29, 2007, 00:03
I did notice that the gas block theads were very thin and rounded. The gas tube did not want to lock up tightly either.
Is the pin that holds the gas tube in place supposed to be a split pin or a solid pin on the L1A1?

June 29, 2007, 00:06
I am not sure, but it shouldn't matter. It just keeps the tube from rotating, even a piece of coat hanger will work.

ETA, if you have problems with the new gas tube and you are sure it is a gas leak, there are easier fixes than replacing the gas block. You can put teflon tape on the end of the tube, or solder the tube to the block. Be sure to check the gas plug and make sure it is a tight fit as well.

June 29, 2007, 03:12
My Century L1A1's gas tube pin is a roll pin. My Century R1A1 and my Imbel (built from kit) both have solid pins. Does not feel any difference. The roll pin seam should face the opposite direction of the tube (facing down).

June 29, 2007, 05:16
When screwing the gas tube into the block, from what I recall, don't thread it in tight. This will induce binding of the gas pistol. Thread in the tube until it is tight, and then back off a few rotations, then pin.

June 30, 2007, 09:23
Thanks for the tips guys. The replacement parts showed up and the new gas tube and plug did the trick. I went with the solid pin insted of the split pin. The rfle will now eject brass on most of the more-open settings. A trip to the range and proper setting of the gas sleve is in order now.
Have a happy 4th everyone.

June 30, 2007, 13:56

I saw this sign in Helena, Montana in 1992: "Be alive on the Fifth. No fifth on the Fourth."

--Radio :wink: