Apparently Stevens had oddball threads. A friend brought me an old Stevens .22 that needed some parts, including a screw. My micrometer told me no modern screw was the same diameter so I turned a soft wood dowel to fit, screwed it in & when removed it was a thread count I'd never heard of. I had to turn a steel rod to diameter & thread it. I must have spent the better part of an hour making 1 screw... the rest of the parts were "fun" challenges too.