Bill, oddly enough, most of the couple of dozen Baker single barrel trap guns I have measured with the Brownell's solid gauges and my bore gauge with measuring increments, measure 2 1/2" chamber length. Most of the Paragon doubles measure 2 3/4" from the same era. Not quite sure why. The Galazan folding multi gauge chamber measurer seems to measure the Trap Gun chambers about half way between 2 1/2" and 2 5/8".

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