I can mount a shotgun ONE TIME and know whether it fits me. O/U, SxS, repeater, doesn't matter. I've also learned that what a gun measures does not always mean it will or won't fit, but it does most of the time.
I have a 32" flat rib Blaser F3 that measures 1 1/2" x 2" x 14 3/4", and EVERY TIME I mount it, I'm looking straight down the rib at the bead, flat , with no rib showing. It shoots where I look.
I also have a 32" DT-10 that measures 1 1/2" x 2 3/8" x 14 1/2", and EVERY TIME I mount it, I'm looking straight down the rib at the bead, flat, with no rib showing. It shoots where I look.
Go figure.
JR
OK, John, I figured.
I figure that,
if it were the same gun with 2 different stocks, meaning the rib/bore relationship was unchanged, those dims might result in a POI change of only 3-4" at 40 yds....essentially the difference between a 50/50 and a 60/40 pattern. That difference would be indiscernible to a lot of shooters.
Since they are 2 different guns, likely with different rib/bore relationships, it's even less mysterious that both could shoot "where you look."
Because the ideal drop depends on the distance between my pupil and cheekbone anchor point, all I have to know is the drop at my eye (DAE) to know where a gun will pattern for me at 32 yds. Consider a parallel comb stock versus a sloping field stock and it becomes obvious that for both to shoot to the same POI the critical dimension they share is the DAE.
My 26" 20ga Fox and my 32" 12ga Fox (and others in between) have slightly different DAC/DAH/LOP but virtually identical DAE of 1.55". They all pattern where I look, essentially flat at 0-2" high @ 32yds.
The key is that 1/8" at the eye correlates pretty darned well to a 2" shift in POI at 32yds.
My trap guns are a 1916 Ithaca Flues SBT with a straightgrip and dims of 1 1/4" x 2 1/8", but the DAE is 1.40" and, not surprisingly, it shoots 5-6" high @ 32yds.
OTHO, my 1974 Perazzi SBT has a full pistolgrip, palmswell and Monte Carlo stock, but with a DAE of 1.38" it also shoots 5-6" high at 32yds.
In a similar vein, a case can be made that LOP as measured from the trigger to the center of the butt is pretty useless. LOP would be a much more meaningful and useful number if it were measured from the center of the palm to the butt.
