I can see where some repros have tapered chambers with the smaller part being toward the nipple and the larger part near the mouth. That makes sense if the reamers get worn from usage.
However, to have it in reverse in a non-bore through cylinder could be done with a boring bar instead of a reamer. Heck, you can do it with EDM too. Why though continues to escape me.
Vigilantibus et non dormientibus jura subveniunt. Molon Labe!