Post by hcompton79 on Apr 2, 2021 22:58:12 GMT -5
So I'm hoping some of the more experienced members here can shed some light on a question I've been having with my Standard Arms Model G.
I purchased a less than complete Standards Arms Model G in .30 Remington a few months ago and have been spending the time to restore this rifle to firing condition including replacing and making some parts for it. This has given me a pretty good understanding of the system and how it works.
While the rifle is now in firing condition, I have found that the rifle tends to be overgassed and ejects spent cases about 20 feet in the air while the ejector deforms brass. As far as I can tell based on the rifle in front of me, the gas system on these rifles can be turned on and off, but is not variable in terms of gas pressure. This is exemplified by the "on" and "off" markings on the gas tube and the design of the gas inlet valve (plug) which is of uniform diameter and has a radial cut in the end. When the cut is lined up with the port in the barrel gas can flow into the gas tube and actuate the piston. When rotated to any other position, the body of the gas inlet valve blocks the gas port in the barrel and prevents semi-automatic function:
imgur.com/a/LcseTzg
The forceful ejection and cost of .30 Remington brass is less than ideal, so I made a variable gas plug that allows the insertion of apertures to vent some of the gas out of the system and tune it for less violent ejection. This works well and drops in place of the original gas inlet valve so is reversible if desired.
Now, I have recently acquired reprints of the 1909, 1910 and 1912 Standard Arms catalogs from Cornell Publications and have been reading them, which has made me reconsider some of the notions I had previously conceived about this rifle. Notably, both the 1910 and 1912 catalogs reference the ability for the gas system to vary the amount of gas applied to the action.
The 1910 catalog states that "If more power is needed to operate the mechanism, as in cold weather, it can be applied almost instantly by opening the gas inlet valve to its full extent."
The 1912 catalog goes further to describe the procedure, stating "To increase the power of the automatic ejection and overcome any sluggishness due to cold weather, open the valve until the index line on the valve stem coincides with the line marked "on" on the inlet at this point. The port to the cylinder is then fully open.
The terms "fully open" and "increase the power" would suggest that the rifle is capable of operating in a state of less than full power, however, as I have observed the geometry of the rifle in front of me does not agree with this, having only the ability to operate with no gas or full gas. It would be possible for the rifle to have at least three gas positions, off-on-full, if either there was a cut in the gas cylinder which allowed some of the gas to bypass the body of the valve with the cut turned away from the port, or if the body of the valve were tapered, achieving the same effect. However, neither of these theories line up with the measurements taken my existing rifle.
So, if anyone else has one of these and has played with it enough, are you able to vary the gas using the stock gas inlet valve, and if so, how?
I purchased a less than complete Standards Arms Model G in .30 Remington a few months ago and have been spending the time to restore this rifle to firing condition including replacing and making some parts for it. This has given me a pretty good understanding of the system and how it works.
While the rifle is now in firing condition, I have found that the rifle tends to be overgassed and ejects spent cases about 20 feet in the air while the ejector deforms brass. As far as I can tell based on the rifle in front of me, the gas system on these rifles can be turned on and off, but is not variable in terms of gas pressure. This is exemplified by the "on" and "off" markings on the gas tube and the design of the gas inlet valve (plug) which is of uniform diameter and has a radial cut in the end. When the cut is lined up with the port in the barrel gas can flow into the gas tube and actuate the piston. When rotated to any other position, the body of the gas inlet valve blocks the gas port in the barrel and prevents semi-automatic function:
imgur.com/a/LcseTzg
The forceful ejection and cost of .30 Remington brass is less than ideal, so I made a variable gas plug that allows the insertion of apertures to vent some of the gas out of the system and tune it for less violent ejection. This works well and drops in place of the original gas inlet valve so is reversible if desired.
Now, I have recently acquired reprints of the 1909, 1910 and 1912 Standard Arms catalogs from Cornell Publications and have been reading them, which has made me reconsider some of the notions I had previously conceived about this rifle. Notably, both the 1910 and 1912 catalogs reference the ability for the gas system to vary the amount of gas applied to the action.
The 1910 catalog states that "If more power is needed to operate the mechanism, as in cold weather, it can be applied almost instantly by opening the gas inlet valve to its full extent."
The 1912 catalog goes further to describe the procedure, stating "To increase the power of the automatic ejection and overcome any sluggishness due to cold weather, open the valve until the index line on the valve stem coincides with the line marked "on" on the inlet at this point. The port to the cylinder is then fully open.
The terms "fully open" and "increase the power" would suggest that the rifle is capable of operating in a state of less than full power, however, as I have observed the geometry of the rifle in front of me does not agree with this, having only the ability to operate with no gas or full gas. It would be possible for the rifle to have at least three gas positions, off-on-full, if either there was a cut in the gas cylinder which allowed some of the gas to bypass the body of the valve with the cut turned away from the port, or if the body of the valve were tapered, achieving the same effect. However, neither of these theories line up with the measurements taken my existing rifle.
So, if anyone else has one of these and has played with it enough, are you able to vary the gas using the stock gas inlet valve, and if so, how?