Can a #1 be rechamber from a 7mag. to a STW or 7ultra. Thanks. fws

Sure Toto, as they say anything is possible with enough time & money. I would think the STW would be least expensive. If you have a #1B it is a rechamber job & maybe a bit of work on the extractor in the case of the Ultra. Jbelk or one of the other rifle masters can verify this.
I had a #1S rechambered to 7mm Dakota. It was a bit more work though because of the banded front sight & 1/4 rib. It's been a good conversion, probably worth the money. I get an easy 200fps over the 7rem.mag. & it's a bit different.

I have often thought of rechambering my No. 1B 7mm Mag to STW. But every time I start to think about it I remember how accurate it is now, and how little gain there is between these two rounds....