You won't get any red from this paring. Red requires "A" at the ASIP Locus. Black only carry "a" and will be aa at the ASIP locus. Thus, you will only get aa from this pairing. However, since both rabbits have a red parent they will both be Ee at the Extension Locus. Thus the only possible combinations are Black or Tort bases with or without broken. Unless of course there are other recessives present in both parents, such as dilute ("d"), chocolate ("b"), or REW ("c").
Breed two chestnuts from red parents, or breed a chestnut back to it's red parents and you should get some reds.