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dsol
December 24, 2008, 11:13
I may just be dense, but I do not see anything obvious that indicates my Century FrankenFal piston is one piece or two piece. Is there an easy way to identify these? It may just be a one piece and I am looking for something that is not there, but I have heard that Century used crappy two piece ones and I want to be sure if I need to swap it out or not.

Thanks in advance to any gurus that answer this... please bear with me, I am sure I will have more dumb questions in the future.

bykerhd
December 24, 2008, 12:25
There is a visible joint on the Century two piece gas pistons where the smaller tail section is fitted in to the larger front section of the gas piston.
No joint ?
It is a one-piece.
But, Century used gas pistons as compliance parts on a lot of their FALs.
Your 922r count may be short.
Depending on what gas piston and other parts that you have.

W.E.G.
December 24, 2008, 12:53
on the right

http://i227.photobucket.com/albums/dd7/rkba2da/FAL%20parts%20pics/falgaspistonsusother.jpg

bykerhd
December 24, 2008, 13:34
Gee W.E.G., that picture looks kind of familiar.:wink:

dsol
December 24, 2008, 14:17
So the one on the right is the two piece? Were the two piece pistons compliance parts or the one piece? I am going to replace the lower eventually with an aluminum one and since I have an inch lower, I will have to get a new H/T/S set so I should have nothing to worry about on the parts count. It came with the standard stock, not the bung hole stock so I hope they did their homework and had enough compliance parts to begin with.

bykerhd
December 24, 2008, 14:36
The two piece pistons were compliance parts.
They may have used U.S. made one piece pistons in later guns.
I haven't seen one.
Century NEVER used more compliance parts than they had to on FALs.
Depending on when yours was put together, there are several possible combinations of parts they may have used.

J. Armstrong
December 24, 2008, 15:22
Originally posted by bykerhd
Century NEVER used more compliance parts than they had to on FALs.


And sometimes not enough :D

dsol
December 24, 2008, 16:30
Originally posted by J. Armstrong


And sometimes not enough :D

You're soooooo comforting... :D

It looks like I have a one piece, so at least there is one part I do not have to replace for reliable function. My ramp needed lots of polishing along with the frame rails. I am going to try ggiilliiees rail widening a little too. Has anyone had a bad experience doing that?

Now if some falfiler can part with a used alloy lower for sale or trade, I will be all set.

Falfegnügen
December 24, 2008, 22:55
What's the origin of all those pistons in the picture?

dsol
December 25, 2008, 00:23
Mine looks like the third one from the left.

bronco_buster
December 25, 2008, 13:49
+1 for identifying the pistons.

Wondering about the origin of the one that is next to the two piece.

Oh, and just to throw this as an aside...would a gas piston possess enough hardness to be used as a burnisher?

bykerhd
December 25, 2008, 22:53
he piston to the left of the Century two-piece is an old TAPCO stainless.
The next one is DSA. I think the next one also.
I don't have a link to the original thread that picture came from a while back.

plinkerneil
October 23, 2009, 17:05
Any idea what the third piston from the left is? I've got one like it.

I'm guessing its from an STG, but I'm hoping somebody actually knows something.

Rich@CGW
October 23, 2009, 22:07
Originally posted by plinkerneil
I'm guessing its from an STG, but I'm hoping somebody actually knows something.

The STG pistons have a threaded hole on the receiver end. ( Only Steyr did this ). Most other genuine OEM pistons have a stained end on the receiver end, which is from heat treating. US made pistons don't have either feature.

There is also US pistons that have 3 gas rings at the front. Imports all have 2

gunnut1
October 25, 2009, 13:32
Phillip (remember him?) had a bent Centry piston at Falfest and it was a one piece.

Fleabus
October 25, 2009, 14:06
I think in the past I have picked up one or 2 of the tapered types 2nd from the right in WEGS pic. Could some give the ID/origin of that type? Appreciate the info and pic, WEG and all...

Rich@CGW
October 25, 2009, 15:35
Originally posted by Fleabus
I think in the past I have picked up one or 2 of the tapered types 2nd from the right in WEGS pic. Could some give the ID/origin of that type? Appreciate the info and pic, WEG and all...

TAPCO

bykerhd
October 25, 2009, 22:33
Older TAPCO actually. Some of the early production were a bit undersize.
Make sure you measure the head diameter of the ones you have Fleabus.
I have gas pistons from different sources running from about .428 up to over .431.
I've found my rifles function best with pistons on the larger side. .430 to .4305.
As long as they don't bind.
Pistons with diameters on the smaller side need more gas because of leakage.
In my very limited experience anyway.
Also, roll them on a hard, flat surface and make sure the tails are straight.
Bent pistons will bind.

Fleabus
October 27, 2009, 18:26
BKHD, Thanks for the suggestion on checking head size and info...