Lets see if we are all on the same page with this
I have always taken it that a 13XX was a 1377 modified beyond factory configuration
regardless of caliber, and that the 1322, is a Crosman model no longer produced,
but could be a stock 1377 converted to .22. The 1325 would be a stock frame with
a .25 caliber barrel. Thats easy!
A gun that has internal mods that do not change the basic function or look of the gun
could still be designated by the factory model.
I have used the designation 13XX to specify an air gun using a 1377 frame that
has been highly modified to something other than a match to a specific Crosman model.
If I am wrong in doing this someone please chip in.
If I am right please feel free to reply as this could help others as well.
I BRAKE FOR BISCUITS