The 307 is not too much for the Marlin, two things were/are wrong with the 307. Marlin is not dumb enough to chamber for a didn't sell. The buying public would not buy it in Winchesters so Marlin would not have done any better. Gun buyers want something new, not obsolete, the 307 just would not sell.
The other thing with the 307 is it's originator, who designed it? Winchester. Who would want to build a new rifle and put their competitors name on it? 307 Winchester is out, 308 Marlin is in.
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