M14 Fail to feed
- Thread starter Petrock
- Start date
you did not get back to us on gas assembly function..... verdict?
rule out the oprod spring guide...... probably not an issue.
if your gas assembly fit and function is as i described it should be.....
is your barrel indexed correctly.... oprod guide correctly positioned.....
take the bolt out , put the oprod, spring and oprod spring guide rod back in... without any grease... and feel for binding by cycling the oprod.
if you drag anywhere and the gas assembly is deemed as functioning..... then check for binding areas near the back of the oprod stroke.
lastly... for now..... put the stock on and verify that the oprod arm is not dragging on the stock
so much easier to diagnose in person..... but i suppose throwing ideas at you from the armchair will have to do.
rule out the oprod spring guide...... probably not an issue.
if your gas assembly fit and function is as i described it should be.....
is your barrel indexed correctly.... oprod guide correctly positioned.....
take the bolt out , put the oprod, spring and oprod spring guide rod back in... without any grease... and feel for binding by cycling the oprod.
if you drag anywhere and the gas assembly is deemed as functioning..... then check for binding areas near the back of the oprod stroke.
lastly... for now..... put the stock on and verify that the oprod arm is not dragging on the stock
so much easier to diagnose in person..... but i suppose throwing ideas at you from the armchair will have to do.
Well everyone I think we have the winner.
The gas piston drop[ed straight out when released. I took my M305 apart and did the same test with it and it took a really good second, maybe almost two for the piston to make it's full travel.
So I took the piston from the 305 and put it into the 14 and it dropped straight down immediately.
Now what are my options and what is this going to cost me?
The gas piston drop[ed straight out when released. I took my M305 apart and did the same test with it and it took a really good second, maybe almost two for the piston to make it's full travel.
So I took the piston from the 305 and put it into the 14 and it dropped straight down immediately.
Now what are my options and what is this going to cost me?
Just need a new piston - good opportunity to upgrade to a Springfield NM, or a Smith, or a Sadlak... 
I think M14Doc can probably help you out!
That is, if your gas cylinder is in spec... if not, it's a new gas cylinder and probably a new piston (if you can measure the piston to make sure it's in spec, then all you need is a new cylinder).
If the 305 piston works in the 305 but drops like a rock in the 14, then it looks like the 14's gas cylinder is out of spec...
-M
I think M14Doc can probably help you out!
That is, if your gas cylinder is in spec... if not, it's a new gas cylinder and probably a new piston (if you can measure the piston to make sure it's in spec, then all you need is a new cylinder).
If the 305 piston works in the 305 but drops like a rock in the 14, then it looks like the 14's gas cylinder is out of spec...
-M
Just need a new piston - good opportunity to upgrade to a Springfield NM, or a Smith, or a Sadlak...
I think M14Doc can probably help you out!
That is, if your gas cylinder is in spec... if not, it's a new gas cylinder and probably a new piston (if you can measure the piston to make sure it's in spec, then all you need is a new cylinder).
If the 305 piston works in the 305 but drops like a rock in the 14, then it looks like the 14's gas cylinder is out of spec...
-M
Ok M14 Doc what are the specs on the piston so that I can measure. I have a digital caliper set so you can be pretty specific on where to measure.
The 305's piston also shot right through the 14's cylinder.... so that looks bad and I'd like to know what my options are in that regard.
i just need to clarify this
please answer these questions as specifically as you can hehehe
is one a M305 and one a real c/a m14 or is the second rifle a M14s?
all pistons are failing the vaccum test in one cylinder but appear to function in the other?
i'll wait to comment until you have answered the above
BUT as for throwing out numbers on piston diameters for chinese rifles...... the variances are all over the place hehehe
USGI and springield or other U.S. spec cylinders and pistons are made to adhere to the standards given in the blue prints of the real u.s. m14. The gas cylinders inside diameter on a U.S. spec item is too tight to even get a chinese piston past the gas plug threads..... in most cases. And the opposite applies to the chinese parts..... gas cylinders are over the U.S. specs considerably and therefore, in most cases , aftermarket , u.s. spec pistons , be they springfield, sadlak, sei, usgi or other....... are two "thin" to be used in chinese cylinders without short stroking.
so...... answer those questions and i'll give you my best advice
please answer these questions as specifically as you can hehehe
is one a M305 and one a real c/a m14 or is the second rifle a M14s?
all pistons are failing the vaccum test in one cylinder but appear to function in the other?
i'll wait to comment until you have answered the above
BUT as for throwing out numbers on piston diameters for chinese rifles...... the variances are all over the place hehehe
USGI and springield or other U.S. spec cylinders and pistons are made to adhere to the standards given in the blue prints of the real u.s. m14. The gas cylinders inside diameter on a U.S. spec item is too tight to even get a chinese piston past the gas plug threads..... in most cases. And the opposite applies to the chinese parts..... gas cylinders are over the U.S. specs considerably and therefore, in most cases , aftermarket , u.s. spec pistons , be they springfield, sadlak, sei, usgi or other....... are two "thin" to be used in chinese cylinders without short stroking.
so...... answer those questions and i'll give you my best advice
QUOTE=M14Doctor;4630996]i just need to clarify this
please answer these questions as specifically as you can hehehe
is one a M305 and one a real c/a m14 or is the second rifle a M14s?
One M305 the other M14s.
all pistons are failing the vaccum test in one cylinder but appear to function in the other?
Yes, though I didn't think to try the M14s piston in the M305 and will attempt that tonight.
i'll wait to comment until you have answered the above
BUT as for throwing out numbers on piston diameters for chinese rifles...... the variances are all over the place hehehe
USGI and springield or other U.S. spec cylinders and pistons are made to adhere to the standards given in the blue prints of the real u.s. m14. The gas cylinders inside diameter on a U.S. spec item is too tight to even get a chinese piston past the gas plug threads..... in most cases. And the opposite applies to the chinese parts..... gas cylinders are over the U.S. specs considerably and therefore, in most cases , aftermarket , u.s. spec pistons , be they springfield, sadlak, sei, usgi or other....... are two "thin" to be used in chinese cylinders without short stroking.
so...... answer those questions and i'll give you my best advice[/QUOTE]
Any and all assistance is always appreciated.
please answer these questions as specifically as you can hehehe
is one a M305 and one a real c/a m14 or is the second rifle a M14s?
One M305 the other M14s.
all pistons are failing the vaccum test in one cylinder but appear to function in the other?
Yes, though I didn't think to try the M14s piston in the M305 and will attempt that tonight.
i'll wait to comment until you have answered the above
BUT as for throwing out numbers on piston diameters for chinese rifles...... the variances are all over the place hehehe
USGI and springield or other U.S. spec cylinders and pistons are made to adhere to the standards given in the blue prints of the real u.s. m14. The gas cylinders inside diameter on a U.S. spec item is too tight to even get a chinese piston past the gas plug threads..... in most cases. And the opposite applies to the chinese parts..... gas cylinders are over the U.S. specs considerably and therefore, in most cases , aftermarket , u.s. spec pistons , be they springfield, sadlak, sei, usgi or other....... are two "thin" to be used in chinese cylinders without short stroking.
so...... answer those questions and i'll give you my best advice
[/QUOTE]Any and all assistance is always appreciated.
Well the rifle has gone to the gun doctor. Apparently the gas cylinder was drilled off center and the inside has rings in it. There is no "seal" around the piston at all. This is a lemon part that needs to be replaced.
On the advice of my smith I'm going to contact the retailer to see if I have warranty.
I'll let you guys know how we turn out.
On the advice of my smith I'm going to contact the retailer to see if I have warranty.
I'll let you guys know how we turn out.
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I had the same problem with my M305S, and it turned out that the spindle valve (turns the gas system off to allow for firing grenades) was totally mucked up with cosmo and powder fouling. A good blast of brake cleaner had it back to normal with no further problems.
