This is what the reamer would look like for a BS only 32/40 "Schuetzen" chamber and what I have in one of my rifles but, you have to be careful with what bullets that you use. This type chamber needs a bullet with at least .002 taper or it will deform the bullet, while BSing if the bullet is to large in diameter.

As long as the bullet BS's w/o deforming, the throat really won't effect accuracy. It should shoot just as well with any throat, as long as the throat isn't to large for the groove diameter and the bullet fits the throat.

A little easier throat to BS would be one that, along the 30 deg transition, at the case mouth, you would start a 1.5 deg taper, starting at a diameter of .322.

You can scale this drawing up to 40 cal or if your serious about getting a reamer made, I could do it for you.

Frank 

Thanks for the reply's, as I only sent my question to CPA on Friday I will wait till I hear from them as well before deciding to whether to proceed or not.  I also asked CPA as to what bullet would be best, currently I'm using a BACO 420 gr bullet that from memory is called a Kidwell Money bullet, it does have a taper and seats easily using my Weber seater.
Mike.