Differences in dimensiones between m1 3006 + 7.62 mm garand cylinders ?

[gladius 2]

Recently ordered a new M1 Garand cylinder on Ebay from an Italian seller. He indicates it will work on both 3006 and Nato caliber 7.62 mm Garands. I intend to use this on my Springfield 43 Garand as I believe the cylinder is no longer in spec. and worn out, to much gas escapes, and fails to cycle. Anyone familiar with Italian mfg. cylinders or can compare US 3006 to Italian cylinders to confirm differences.

 

[just having some fun]

The cylinders are the same

what is the difference as I understand in the size of the gas port in the barrel

the piston on the oprod usually wears faster than the gas cylinder ... a gas piston smaller than .525 would be a reject

The gas plug is designed to work with an M1 Rifle that has a gas system that is in spec. That is to say, not worn beyond the normal reject levels. That would be a gas piston with a diameter between 0.5250″ and 0.5260″ and a gas cylinder that is between 0.5280″ and 0.5320

I have never seen a Perfect (as new) gas cylinder

a worn gas cylinder and a large or oversize piston will still function a m1 garand ( using the right powders)

 

[purple]

You can measure the inside dimension of a gas cylinder with a plug gauge inserted at the front to verify go or no-go. Another factor is the outside dimension of the barrel at the gas port area. The aperture in the gas cylinder must also be correctly positioned to allow gas to flow from the gas port into the cylinder. Selective fitting of gas cylinder locks can help to locate the gas cylinder correctly. Then there is the gas plug which must be fully closed. If the inner face of the plug is cracked, it will allow gas to escape. The best way to check all this is to assemble and shoot the rifle to test for function. Keep the gas plug tight before and during shooting.

Italian and US gas cylinders are completely interchangeable and both will work on a 7.62 or .30-06 Garand.

 

[gladius 2]

All very good information to know. I have two op rods that supposedly all gauged correctly but after testing they both did not cycle properly or short stroked , I was told that the problem could be worn gas cylinders, so that is my next option, I replaced the recoil springs with new Wolf ones three years ago, meas. To correct length that did not change the the issue the ammo I am using is 1963 G.I. Ball Lake City mfg. Hopefully a new gas cylinder will result in better performance. Thanks to all that responded. Great info.

 

[purple]

All very good information to know. I have two op rods that supposedly all gauged correctly but after testing they both did not cycle properly or short stroked , I was told that the problem could be worn gas cylinders, so that is my next option, I replaced the recoil springs with new Wolf ones three years ago, meas. To correct length that did not change the the issue the ammo I am using is 1963 G.I. Ball Lakefield mfg. Hopefully a new gas cylinder will result in better performance. Thanks to all that responded. Great info.

Do the op rods pass the tilt test? A binding op rod may be a cause. To do the tilt test, strip the rifle down to the barreled receiver with all parts removed, except for the bolt, handguards, gas cylinder and lock. Hold the barreled action in a horizontal position and raise and lower the muzzle to a 45 degree position. The bolt and op rod should open and close freely from their own weight.

After doing the tilt test, the barreled action can be installed in the stock and the op rod cycled manually to check for binding on the stock and stock ferrule. Sometimes it's necessary to remove a bit of wood from the op rod channel or some metal from the stock ferrule.

Gas cylinders are getting expensive. If you suspect a worn gas cylinder, a .532 diameter pin/plug gauge inserted in the threaded end will act as a no-go gauge. If the gauge can be inserted past the threaded area, the gas cylinder is excessively worn.

Another check is to make sure the gas port in the barrel is free of carbon fouling. A #47 drill shank (.0785 diameter) can be used as a gas port clean out tool on a .30-06 barrel.

 

[gladius 2]

Tilt test

A few years ago after rebarreling the garand, I had a knowledgeable CGN buddy examine and gauge the two op rods I had, they were both to spec. as I did not have the gauges, he did, I used the best one of the two, they were tilt tested and were functional, but when I test fired, I had failures to feed and eject, clip did not always eject, rounds continually failed to travel up into the breech, bolt would not go into battery. Used correct g.i. ammo and even installed a new Wolf spring trimmed to correct length.Problems continued. So I have finally found a source for a new gas cylinder tube and I am hoping this will ultimatley fix my problem. Fingers crossed.

 

[just having some fun]

but when I test fired, I had failures to feed and eject, clip did not always eject, rounds continually failed to travel up into the breech, bolt would not go into battery. Used correct g.i. ammo and even installed a new Wolf spring trimmed to correct length.Problems continued. So I have finally found a source for a new gas cylinder tube .

Multiple problems
feed and eject ..... If Gas cylinder is out of spec it will not give you feeding problems ( unless it is not coming back far enough ) and you are getting short stroking and not getting a new round

rounds continually failed to travel up into the breech, do you mean round is jamming part way in ?

clip did not always eject
bolt would not go into battery
Multiple problems

Have you tried a tilt test (with no Spring ) ..... In the wood stock

In the past I have bought rebuilt Op rods that were in spec (told they were in spec) but had problems that needed tweeking and some times some wood need to be removed

 

[gladius 2]

Hopefully a new gas cylinder will give me a starting point to continue diagnosing the issues, process of elimination, new barrel, new recoil spring and new gas cylinder, will eventually find the the problem through elimination.

 

[purple]

Check op rod spring for proper length; max is 20.25 inches, min is 19.75 inches. Wolf op rod springs are too long and must be cut to specified length. The rifle must be lubed with grease at specified grease points. The op rod spring must also be lightly lubed with grease. It's also worth checking the interior of the op rod tube for fouling/corrosion that could inhibit functioning.

There are several possible causes of short stroking besides a worn gas cylinder. A pin/plug gauge will verify that the gas cyl is within wear limits.

Failure to eject a clip isn't due to gas problems. Failure to feed doesn't necessarily indicate a gas supply problem, unless there is insufficient gas to let the bolt travel far enough to the rear to strip a round from the clip.

 

[gladius 2]

Thanks for the info purple, I am out of town for awhile, so I will remeasure and confirm that my spring length is correct length when I get back home. Thanks for the info.