Yes, it looks like it will hold 6 with 5 in the tube and one on the carrier with the action open. But it you try to go to an action closed, hammer down on an empty chamber condition, it will not fully close. This is because when the action is closed, the round on the carrier is pushed into the magazine, and the magazine will not hold 6 rounds.
Based on measureing, it looks like on a Chiappa 87 it might be possible to load 6 by shorting the follower. Might have to shorten the mag spring as well. Only way to know for sure would be to try it. My Chiappa has the Lassiter "drop two" mod so it is not a candidate. I'm reluctant to spend the money on a Cimarron 87 not knowing for sure if it can be made to hold 6 rounds. If any of you purchase one for wild bunch use and attemp the modifications to make it a 6 rounder, I sure would appreciate hearing about it. Thanks in advance.
TR