Having a bit of a problem with my air pump. Its a Blackburn floor pump. The issue is the end that goes on the schrader tire vale is sooo snug. I blame it for a popped tube (at home thank goodness!) that I just had to replace. The rim tape is in good shape and I used some emery cloth to smooth down the outside edge of the hole in the wheel. I really don't think that spot caused the cut in the stem, but maybe so.

Is a threaded chuck available, and from where? Just started looking today. Milton and Schraders websites were no help.

Considered some sort of lube, but the threads on the stem seem to keep that from working on a repeatable basis. I have not tried anti-seize.

What am I missing?

You are missing presta tubes.

haven't had any problems with Schraders, and I prefer them because that is also what is in my kids' and wife's bike tires, so I can air them all up at once quickly.

Sounds like you have taken good precautions. Continue use and monitor is what I would do.

I use a Serfas FP-200 floor pump. The Schraders are tight on it, too. I haven't had any problems with tubes popping though. My tubes are Sunlite 700x28-35.

Good luck, I hope it was just one bad tube.

You might be able to make it wide enough by going around the hole with a rat-tail file. If that seems like too much work, use a drill to widen the hole. I don't remember the exact size. Sheldon Brown says you need to use a 21/64 inch bit.

Last time I tried this, I realized I didn't have that bit, so I think a 5/16 might work.

I have a Leyzne floor pump and it has a reversible end that threads on schrader or presta. Might want to check something like that out.

When my Nashbar Orange pump finally died,I replaced it with a newer model. The smart head(Schrader/Presta) was very tight at first,but then loosened up a bit. Of course,I was using it at my bike clinic,so it was being used over a dozen times a week,so it didn't take long to 'break in'. Sounds like you have the same issue. I would just take it carefully and let the head break in.

Thought about it some more and had an idea. I'll share it if anyone is interested. Cut the stem out of the old tube and shaved the rubber back from the end opposite the threads. Chucked it up in the cordless drill and run it in and out of the air chuck (turning in both directions) and wallowed it out. Checked frequently, by slipping it on by hand, until it was not so difficult to slide on the valve. Still clamps/seals very snug. If you try it, hold the valve so the bits of rubber that are removed fall out of the valve, not into it. Kind of speeds up the break in period!