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Old 10-11-2018, 08:03 AM
Hapworth Hapworth is online now
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Originally Posted by HorizontalMike View Post
...What I am wondering about is... Is ther any way to determine how much energy/fps is lost for each additional .001" of additional gap? I have been searching for this specific parameter, however, I have not found such information thus far...

...Bottom line, I realize that I am going to lose "some" fps with a wider gap, but just how much is the question...
The linked test from Ballistics by the Inch is a good read, and there are a few similar tests others have conducted over the years, but I agree they're few and far between.

The general takeaway is the greatest drop occurs between .000 and .001", numbers we're never operating at anyway, and the remaining drops are lesser and fairly consistent each step of the way out to about .010".

In all it averages to about 10 feet per second for every one thousandth gap increases, though as stated not in equal increments -- the biggest drop is front loaded. I recall that it starts to open up again once you get past .10" or .012", but would have to find the original test producing those results.

For revolvers with varying but in spec gaps, the difference will be negligible compared to other factors affecting muzzle velocity, with BLUEDOT37 spoke well on.
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