The idea posted by foose (to use the worst end for the MMT) is a good one.
For the front end, make a cardboard template with a hole to match the O.D. of the BT. Friction fit would be best but if you cut a template a little loose, wrap the outside of the BT with a few strips of paper to make the fit tighter. Do not glue any of this; the template will be removed after you work the BT itself. The template is only there to hold the BT round during the next step.
Apply some CA to the inside lip of the crimped BT. I use "dollar store" CA for this and it works just fine. (The kind that comes packaged with three or four little tubes on a card for a buck.) If you have fancy CA that will also work just fine. Drip a couple drops of CA into the front end of the BT and smear it around with a Qtip. Work it toward the lip, and maybe a half inch back into the front end. The objective is to SOAK it into the cardboard, not to build up a thick layer, so don't leave a puddle laying there to cure into a bump. Anyway, a few drops of CA at several locatns around the inside surface should be enough to reinforce the cardboard. Let cure thoroughly (like, overnight) and then remove the outer template.