R1A1 FAL Piston Binding & Gas Plug Question

[Dave Markowitz]

I recently bought a new Century R1A1 FAL on a South African lower receiver and Century upper. After I got the gas plug out tonight I discovered that the gas piston is binding in the hole where it passes through the upper receiver.

The piston appears to be one piece and has no markings on it, so I'm not sure if it's surplus or Century-made. It doesn't appear to be visibly bent. I tried putting it through backwards (i.e., put the base in the hole from the receiver towards the muzzle) and it bind that way, too.

I'm wondering of the diameter of the piston or the hole through which is passes is off. What are the correct diameters of these parts?

I've done several searches through the forum archives. How should I fix the problem?

Also, can I replace the gas plug with the grenade launcher sight with a standard metric gas plug? The gas plug with the GL sight is a real PITA to remove.

Thanks.

 

[Ian Sean]

The gas plug is a direct change out, I replaced my grenade launcher type as well with a standard metric.

As far as your Piston "binding" are you running it through with or without the spring? The spring keeps the piston nice and centered and with a pencil, pushing on the piston with the plug removed it should move relatively easy other than the spring tension. Without the spring it does meet more resistance and will bind up.

The Century recievers are known to have misaligned gas piston holes, and the other possible problem is that the barrel is not properly timed (straight) when it was installed. Both maladies common to Centurys.

You may want to check the falfiles for specific fixes and troubleshooting.

http://www.falfiles.com/forums/index.php

 

[usp_fan]

Sean nailed both of the areas to check. I'd vote for a mistimed barrel. Did you have to dial in lots of windage to get the rifle to hit where you were aiming? This would be another indicator that the barrel is turned to far / not enough into the reciever.

--usp_fan

 

[Dave Markowitz]

I haven't shot the rifle yet, so I can't speak to the windage issue.

I discovered this last night when I removed the gas plug and the piston didn't spring out. When I tried pushing down on it, it didn't want to move. I used a punch to apply pressure to the rear of the piston to pop it out the front of the gas tube.

Thanks guys. Any more insight?

 

[Dave Markowitz]

The Big Brown Truck arrived this afternoon and dropped off my R1A1 back from Century. I'd decided to give CAI a crack at fixing it, since it's still under warranty. Along with the rifle, were the 500 rounds of 9mm that I ordered on Saturday from Natchez. (It's a good thing the office closed early, since I had to sign for the rifle.)

Upon opening the box, I was pleasantly surprised to see the cheap blue sleeve that I'd sent the rifle off to Century in had been returned. I didn't really care if I got it back since it's almost disposable, but it's nice to see that they were paying attention. When I took the rifle out of the box I saw an orange chamber flag sticking out of the ejection port, and after verifying myself that the gun was empty, I removed the gas plug.

The first time I removed the gas plug, a couple of weeks ago, the gas piston stayed stuck in the gas tube due to binding. Today it popped right out, as it should. When I broke open the rifle, removed the bolt carrier and bolt, and receiver cover, what Century had done to fix the binding was obvious. The hole through which the piston hits the bolt carrier had been reamed out. With the gas piston spring removed the piston now drops freely through the receiver. It's a little sticky pushing it back forwards, but as I understand it, this is normal when the gas piston spring isn't in the gun.

Judging by the carbon deposits on the piston, it appears that Century test fired the rifle before shipping it back to me. So, I'm cautiously optimistic that it's fixed. I may shoot it this weekend and see.

 

[P95Carry]

Hi Dave - I like the sound of the apparent service you received.

CAI does have somewhat of a rep' for ''throwing'' these guns together! My L1A1 from a coupla years or more ago was a bear with feeding - and tho I thought of sending back, in fact did some cautious Dremel work to smooth the breech feed chamfers. That has seemed to do the trick.

I made a small sight change and dialed it in again Sunday - shot just great - gas setting #3 BTW seems to be right for me. It also seems to digest SA, Portugese and Australian ammo well.

When they run well they are good guns IMO - tho I do prefer on balance my metric FAL on an Imbel.

Hope your next test run is successful.