First, just buy a new bleeder and see if it will seat. Don't try to torque any bleeder down too much, they are very easy to brake and the seat in the caliper is easy to gall. I would try to fix the problem before installing speed bleeders.
If that doesn't do the trick then see if you can figure out what the problem is. It's either the seat in the caliper or the tip of the bleeder. There are seat cutting tools which can redo a galled or dented seat in the caliper. Since this requires cutting a bit of metal, full disassembly and thorough post-cut cleaning is recommended. It's not a terribly difficult job, but it does take care and patience.
If that doesn't do the trick then see if you can figure out what the problem is. It's either the seat in the caliper or the tip of the bleeder. There are seat cutting tools which can redo a galled or dented seat in the caliper. Since this requires cutting a bit of metal, full disassembly and thorough post-cut cleaning is recommended. It's not a terribly difficult job, but it does take care and patience.