lol all it takes is one thread and now a but-fed pump is on my "I want list"...
I have not seen such a gem, and a quick search of google defied me. I could rhyme off (as done already) a few manufacturers who made but-fed rimfires, but they are all semis. No one pegged the early Marlin 88 so I call dibs on it. N'er owned a nylon bolt action, but pretty sure they have either a forward tube or a box magazine ("clip" according to Remington's own lingo/packaging).
I've never had a problem with feeding from any buttstock fed rimfire I've owned. Tubes were never bent, or lost (watch what'll happen now...soon WTB magazine parts ad in EE). Many Mossbergs, and a few Remington 66's passed through. I'll attest to Nylons not being very fun to reassemble. Anecdotal trivia/add on: Watch how they work closely. The bullet seems like it's squirted into the chamber...I imagine trouble with feeding would be serious trouble.