gas piston an its bore size for the 30 cal caebine

morning all would like to now the dimensions of the carbine gas piston and it bore size with the correct tolerences an or where to seen the drawing and there related dimensions could bee seen thanks bill possibly a web site that may show the dimensions of the items??

Carbine Info, Blueprints, Posters, Mouse Pads, Coffee Mugs These guys have the info...

Kuhnhausen "The U.S. .30 Caliber Carbines" Vol III, P. 103


Dia. of "piston ring" 0.3997" -0.0005". Edges broken/chamfered 0.005"
Dia of cylindrical portion 0.300" - 0.001"
Cyl- length 0.705" - 0.010" plus ring length 0.140" +/- 0.003"


Bore 0.4000" +0.0007" (not easy to measure without a proper bore gauge - slide gauge/vernier calipers not accurate enough)

Hmm, a letter "X" drill bit is 0.397" and a "Y" bit is 0.404". Wonder if the "Y" bit could be spun against some grit paper in a drill or lathe to a final diameter of 0.400"? That would make an easy plug gauge...

Russ

Possibly the bore could be measured with a small telescoping gauge and a 0-1" mike? Can't remember how small those gauges will go - could be close. - Bob

thanks guys very much !!!! bill surely did help a lot !!!