Win stock question
 

Is it possible a 57499xx Winchester could have a 4'' barrel channel non M2 stock on it, or is that too early?

The long channel stocks first appeared at the beginning of 1945 from what I've read. The stock you need would be a low wood oval cut with just a crossed cannons acceptance mark; in other words no WRA over GHD. On the bright side the long channel stock you describe is quite valuable to the right collector.

I asked 6 Ring that same question and although I deleted the message I think he said they showed up as early as 5.8 but more common to see at 6.5 to 7.2

Didn't the "real" low wood with WRA over GHD and crossed cannons only occur during 5.7 to 5.8 ("only", meaning for the most part)?

At the very least the WRA over GHD low wood stock oval cut was seen from the beginning of the 5,549,922 block that extended into the 5.83 range. The changeover to the crossed cannons only happened just past the 5.70 range with some mixed use of both stamps. Of course with the WRA over GHD could have been seen just before that first range I used and just past the last as there's all kinds of weird things that happened building these weapons.

My 5.65 Winchester (from DCM) has the WRA over GHD & Crossed Cannon.