I'm going to suggest you tilt back the front face of the feederhouse on an R42/52. If the 315 is too nose-down, it may be causing the pushing in front of the cutterbar. The poor feeding in short beans??? All those 300 series heads are like that...sorry. The sickle is too far away from the cross auger. The fix?? Start by raising the cross auger and moving it forward as FAR as possible. You might even add a couple half links to the drive chain to get it forward as far as I like. The flighting height can be up to one inch off of the floor and still work in soybeans. This will NOT work for wheat, oats, etc, but works very well in soybeans. Next, attach a piece (as long as the header is wide)of rubber hose 2" to 2 1/2" in diameter to the top of the cutterbar using guard hold down nuts to attach "P" clamps every 12 inches or so, to secure the hose. This trips the soybeans over it (also acts as a rock guard)and allows the reel to pull the crop into the auger farther. The reel must be back to the point of rubbing the auger and lowered down to the point of getting the reel teeth cut off when the sickle is pushed clear up(may require lowering hyd rams one hole and then adjusting back up with height adjustment screws). You can also make rubber flaps/sweeps over each row attached to the reel to help push the short bean crop to the cross auger. If you make enough changes to one of these heads, they work pretty good in short beans. If you don't, you'll be miserable.