Not long after I took up turkey hunting, I bought my very first turkey call, a Viper box call (that I later lost somewhere in Middle GA, I think) and a guy I trusted took it and worked it over with a metal file.
That did two things....First, it gave the call a raspier and less "store bought" tone. The other was that it made the call work better and hold chalk better.
I started doing this whenever I got a box call...even tried it on a few of my slate calls and liked the grooving on those, too.
I'm not recommending that everybody do this. I certainly wouldn't alter a glass call with a file...but I always liked the tone. Never had a complaint from a gobbler, either.
