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Posted: 8/19/2005 9:49:34 PM EDT
OKay,

 I picked up the gun today from my friend who purchased it.
I havent fired it yet, but everything looks good so far.
Cleaned the gun, Gastube, Piston Gasglug.  Cleaned out the gasport with a toothpick.
Pushed all the way through with no problem. This is an IMBEL INCH gun with a thumbhole stock,
no brake.  Hand cycles well with live ammo and INCH mags.  Wont have a chance to fire it until
Sunday. But i cant see why it wont cycle.   It has an angled gasplug and it is set properly to the
"A" setting, not the Grenade setting.  Gas piston looks good too.  Clean and straight w/No wear.

Anybody see anything i may be missing here??

KyARGuy
Link Posted: 8/19/2005 11:35:03 PM EDT
[#1]
Never hand cycle live ammo unless you are at a range.
Link Posted: 8/20/2005 3:42:38 AM EDT
[#2]

Quoted:
Never hand cycle live ammo unless you are at a range.



Why not?  The safety was on and the gun was ponted in a safe (at the ground) direction
and no finger on the trigger.

So what's the problem?  Sorry im not one of those anal retentive gun safety freaks i avoid
when i go to the range.... you know them. The ones that need to make sure that everyone is locked in their car when they decide to go down range to check targets, or that you arent even looking at the trigger of your unloaded gun for fear that you might use your psychic powers to will a bullet into the chamber, and then aim it and pull the trigger with your mind.

Or maybe your thinking the bullet would go all the way through the earth and hit
who ever is on the other side??  OMG !! how wreckless of me to do that!!

Gimme a break...

KyARGuy

Link Posted: 8/20/2005 9:08:45 AM EDT
[#3]
I had to close the gas regulator up a good bit on mine to get it to cycle. I worked on it  a little and after a while I was able to get it running on a mid range setting. Also the recoil tube and springs were full of grit on mine. I had to clean all the parts and oil them.
Link Posted: 8/20/2005 2:01:45 PM EDT
[#4]

Quoted:

Quoted:
Never hand cycle live ammo unless you are at a range.



Why not?  The safety was on and the gun was ponted in a safe (at the ground) direction
and no finger on the trigger.

So what's the problem?  Sorry im not one of those anal retentive gun safety freaks i avoid
when i go to the range.... you know them. The ones that need to make sure that everyone is locked in their car when they decide to go down range to check targets, or that you arent even looking at the trigger of your unloaded gun for fear that you might use your psychic powers to will a bullet into the chamber, and then aim it and pull the trigger with your mind.

Or maybe your thinking the bullet would go all the way through the earth and hit
who ever is on the other side??  OMG !! how wreckless of me to do that!!

Gimme a break...

KyARGuy





Then feel free to cycle live ammo
Link Posted: 8/20/2005 6:27:42 PM EDT
[#5]

Quoted:

Quoted:

Quoted:
Never hand cycle live ammo unless you are at a range.



Why not?  The safety was on and the gun was ponted in a safe (at the ground) direction
and no finger on the trigger.

So what's the problem?  Sorry im not one of those anal retentive gun safety freaks i avoid
when i go to the range.... you know them. The ones that need to make sure that everyone is locked in their car when they decide to go down range to check targets, or that you arent even looking at the trigger of your unloaded gun for fear that you might use your psychic powers to will a bullet into the chamber, and then aim it and pull the trigger with your mind.

Or maybe your thinking the bullet would go all the way through the earth and hit
who ever is on the other side??  OMG !! how wreckless of me to do that!!

Gimme a break...

KyARGuy





Then feel free to cycle live ammo




Some people have to learn things the hard way I guess.  :shrug:
Link Posted: 8/20/2005 8:36:25 PM EDT
[#6]

Quoted:
I had to close the gas regulator up a good bit on mine to get it to cycle. I worked on it  a little and after a while I was able to get it running on a mid range setting. Also the recoil tube and springs were full of grit on mine. I had to clean all the parts and oil them.



I will check it, thanks.
Im going to Mic the piston to see if it varies in dimension from the one i have that functions peoperly.
Might check the gastube too, i guess it could be out of spec (worn) and could be letting
the gas get by with out effecting the piston.

Off to the range tomorrow to see if it works!

KyARGuy
Link Posted: 8/20/2005 10:22:44 PM EDT
[#7]
Anyone have the measurements (Dia) on a new Gas piston?

Need to know dimensions to check for wear on current one.

KyARGuy
Link Posted: 8/20/2005 11:50:52 PM EDT
[#8]

Quoted:

Quoted:
Never hand cycle live ammo unless you are at a range.



Why not?  The safety was on and the gun was ponted in a safe (at the ground) direction
and no finger on the trigger.

So what's the problem?  Sorry im not one of those anal retentive gun safety freaks i avoid
when i go to the range.... you know them. The ones that need to make sure that everyone is locked in their car when they decide to go down range to check targets, or that you arent even looking at the trigger of your unloaded gun for fear that you might use your psychic powers to will a bullet into the chamber, and then aim it and pull the trigger with your mind.

Or maybe your thinking the bullet would go all the way through the earth and hit
who ever is on the other side??  OMG !! how wreckless of me to do that!!

Gimme a break...

KyARGuy




Well, if thats the way you feel then get ready to be on your roof patching some holes.
Link Posted: 8/21/2005 5:49:18 AM EDT
[#9]

Quoted:
Anyone have the measurements (Dia) on a new Gas piston?

Need to know dimensions to check for wear on current one.

KyARGuy


0.429" nominal
Link Posted: 8/21/2005 9:20:29 AM EDT
[#10]
There were some US made ones that were undersized for an inch tube. Something like .427 . I got one in a thumbhole conversion kit once. I replaced it with a .430 one from the same company. They swapped it for free.
Link Posted: 8/21/2005 6:21:37 PM EDT
[#11]
Link Posted: 8/21/2005 8:26:47 PM EDT
[#12]
OK, Took it out today but the range was closed for a match.
Backup range unavailable due to Brush hogging.  

BUT...In talking with a couple of guys today i think we pinpointed the problem.

The gas regulator on the gun in question if very loose. You can press it down against the spring and
it moves quite a bit. It is probably letting gas by, so that no matter where you set it, it still lets
the same amount by.  It is an INCH gun where the regulator is held on by a spring clip, as opposed
to the METRIC version that threads to the rear of th gas block.
I took the regulator off and placed a shim to completely block the gasport when the regulator is
replaced.  I will test fire it tomorrow wih the gasport blocked with the shim.
I am going to bet it works fine.  I will have to get a replacement regulator for it and it
should be good to go.

Tim, do you have a spare INCH gasblock regulator you can part with??

I'll post more after i shoot it on monday.

KyARGuy
Link Posted: 8/21/2005 8:46:12 PM EDT
[#13]
Link Posted: 8/22/2005 1:16:40 PM EDT
[#14]
Got back from the range and it still doesnt work.

I tried 3 different gas pistons, including a new TAPCO.
Cut a shim to completely block the gasport and placed it under the regulator.
Worked a couple of times but nowhere close to being reliable.

Did notice that the retaining spring would work loose and back off the nut that is to the rear
of the gas regulator.  The Reg would move rearward slightly and push the retainer off the nut.

Pushing the REG forward and reseating the spring nad a minimal effect on the function.
Out of 35 rounds shot through it, only 5 were in a row with feeds and extraction.
The owner can send this gun back to CAI to get it repaired, but if it were me, i think i would send it off
to a smith to get fixed. Other reason it that it is on an IMBEL receiver and if they did replace the gun, i'd be fearful of getting a generic receiver model. ONLY THING  in couldnt try was a different gasplug.
Maybe the gasplug is just to loose and allows too much gas blowby... i dont know.
I do think the regulator is bad so im going to replace that for sure, and i suppose the gasblock
could be bad too??  Would a worn out gastube do this??

Back to the repair table...

KyARGuy
Link Posted: 8/22/2005 6:21:32 PM EDT
[#15]
Take off the hand guards and be sure that the cross pin is in its hole where the gas tube screws into the gas block. This has caused alot of guys to have problems. If your cross pin is missing, you can cut a small piece of coat hanger to work and that should solve your problem. A missing cross pin will cause sufficient gas leakage to cause malfunctions.
Link Posted: 8/23/2005 6:38:23 AM EDT
[#16]
The regulator is part of your problem, a loose gas plug can cause gs to be lost.  As alrerady mentoined the gas tube retaining pin make sure it is in place or you will loose to much gas.  If it is there take it out and unscrew the gas tube then screw it back in untiltight then back it off until the pin can be reinserted.  
What is happening when you are having failures, try to explain in detail, so we can try to help you out.  Lastly, what kind of Ammo are you using?
Once you replaced the regulator and rechecked everything else, you should check to see what size opening you have in your gas block I believe the factory size is around .096 it is said the you can factory iimprove the design operation by opening this up to .109 but no more then .120.
I measured friend of mine that had a DSA made barrel that measured out to .128.
Opening the gas port will give you more gas I usually take mine out to .113, and I don't seem to have any problems with that.
I have an old .30 cleaning rod I stick in the barrel and then I step up with drill bits to get to the hole diameter I want.  When the cleaning rod turns then you are through to the inside of the barrel, if you can get it tight then you will reduce the buring.  Good luck
Link Posted: 8/23/2005 9:33:35 PM EDT
[#17]

Quoted:
The regulator is part of your problem, a loose gas plug can cause gas to be lost.  As alrerady mentioned, the gas tube retaining pin make sure it is in place or you will loose to much gas.  If it is there take it out and unscrew the gas tube then screw it back in untiltight then back it off until the pin can be reinserted.  
What is happening when you are having failures, try to explain in detail, so we can try to help you out.  Lastly, what kind of Ammo are you using?



I blocked the gas relief hole with a shim to force the gas through the action. No effect.
It is like the gas pressure is not getting to the piston. When it fires, the regulator seems to be moved rearward pushing the retainer spring off the nut it holds on to.
Gas tube retaining pin??  Do you mean the gasblock crosspin?? It is in tight with no visible leaking.
It feeds when cycled by hand, no FTF, and extracts fine.  When fired, gun goes BOOM, bolt comes
back about 1 inch or so, and partially extracts shell. Stops dead. Extract spent shell, let bolt forward,
repeats previous steps.  Ammo is SA .308 in battle packs.


Once you replaced the regulator and rechecked everything else, you should check to see what size opening you have in your gas block I believe the factory size is around .096 it is said the you can factory improve the design operation by opening this up to .109 but no more then .120.
I measured friend of mine that had a DSA made barrel that measured out to .128.



Gasport is clean and wide open. I can stick a round toothpick through it clear down to the barrel
through the top of the gasblock.  I dont think it needs to be opened any larger than it is.

It did feed 5-6 round properly yesterday, but i couldnt repeat what i did to make it work that one time.

Any help is appreciated and thanks to all ... i want to solve this one!!

KyARGuy





Link Posted: 8/24/2005 10:32:54 AM EDT
[#18]

I blocked the gas relief hole with a shim to force the gas through the action. No effect.
It is like the gas pressure is not getting to the piston. When it fires, the regulator seems to be moved rearward pushing the retainer spring off the nut it holds on to.
Gas tube retaining pin?? Do you mean the gasblock crosspin?? It is in tight with no visible leaking.



Remove the regulator. See the small dia pin that retains the gas cylinder? The cyl has a top and bottom. It needs to correctly aligned----------screw in handtight and back off and align flat.


Check the dia of the gas port----------I would open it up as was suggested


What is the length of the barrel?
Link Posted: 8/25/2005 8:47:28 PM EDT
[#19]
I see it now.
Is the pin on the under side of the part where the gas tube connects to the gas block just above the
spring that indexes the regulator??  I see it on my rifle, but will have to check the troubled gun tomorrow
at the shop...


It's the SMALL cross pin on the bottom where the cylinder goes in right??

The gun has a 20" barrel.
Thanks!! KyARGuy
Link Posted: 8/25/2005 10:15:46 PM EDT
[#20]
That be the little guy.


The gas systems on FAL's all "leak" to a degree. Depending how much usage the gun saw in it's lifetime will effect this leakage.

Aside from slop in the gasplug to block fit another source is the cylinder. Remove pin and cylinder to clean and inspect. If the threads or the bore is corroded it should be changed out.


I do believe bumping your port dia to .110-.116 will solve your problems tho...




Also note---Keeping in mind this is a CAI gun...

You might want to check headspace. Too tight HS will stop the gun from running. You want 1.632---1.634
Link Posted: 8/26/2005 2:12:41 PM EDT
[#21]

Quoted:
That be the little guy.


The gas systems on FAL's all "leak" to a degree. Depending how much usage the gun saw in it's lifetime will effect this leakage.

Aside from slop in the gasplug to block fit another source is the cylinder. Remove pin and cylinder to clean and inspect. If the threads or the bore is corroded it should be changed out.


I do believe bumping your port dia to .110-.116 will solve your problems tho...




Also note---Keeping in mind this is a CAI gun...

You might want to check headspace. Too tight HS will stop the gun from running. You want 1.632---1.634




Clean or replace recoil springs too............. dirty or worn ones will give you problems ~
Link Posted: 8/26/2005 7:45:27 PM EDT
[#22]
Worked on it a little today.

Pulled the gastube and re installed. That little pin was a roll pin...Mine is held in with a solid pin.
I will replace it with a solid pin, and will test fire it tomorrow after work.  Hopefully it will function
properly and it will all be over.  I have a spare Gasplug to try in it also.  If this doesnt do it,
then it has to be the headspace.  Off it will go to get repaired.

Wish me luck.

KyARGuy
Link Posted: 8/27/2005 5:50:14 AM EDT
[#23]
The pin should be a dowel pin.
Have you removed the gas plug and actually looked to see that it wasn't totally clogged up? I've seen plugs that were so corroded and plugged off it acted like it was on the "grenade" setting.
Link Posted: 8/29/2005 7:29:47 AM EDT
[#24]

Quoted:
The pin should be a dowel pin.
Have you removed the gas plug and actually looked to see that it wasn't totally clogged up? I've seen plugs that were so corroded and plugged off it acted like it was on the "grenade" setting.



The pin has been replaced by a solid pin and the gas plug is clean.

I shot it and it still didnt work properly, unless you blocked the gas relief hole with a metal shim.
It ran great with the hole blocked.  Right now i'm thinking it is going to need a new gas block,
regulator, and gas plug.  Its just letting too much gas by the to work the piston properly.
It doesnt even come close to cycling the action.

Thanks for all the help on this one!!
KyARGuy
Link Posted: 8/29/2005 11:02:13 AM EDT
[#25]
Link Posted: 8/29/2005 3:46:31 PM EDT
[#26]
My Century L1a1 needed to be properly headspaced (it closed easily on a "field" gauge), and have the gas port opened up (I used an electric drill) in order for it to shoot reliably.

It took me years to figure that out...
Link Posted: 8/29/2005 10:02:09 PM EDT
[#27]
We did bump the gasport size up from a .096 to a .1015 and it still wouldnt run with out the blocking shim
under the regulator.  I do think the regulator is way too loose and doesnt block the gas relief hole sufficiently to allow the action to work.  

Might try to open the hole upi a bit but i dont think it is the correct fix for the problem.
Probably should try a new regluator first then try to open it up more.

Thanks, KyARGuy
Link Posted: 9/28/2005 4:58:14 PM EDT
[#28]

Quoted:
Never hand cycle live ammo unless you are at a range.



the FAL firing pin spring will keep the FP completely off the primer unless the hammer drops.

this is not a safety issue unless your pointing it at your buddy or have it on fire with finger in triggerguard.  Give the guy a break
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