Quote:
Originally Posted by Drew Hause
As a victim of a K through post-grad education in the great State of Missouri, this works for me 
http://www.omahamarian.org/trap/shotshellenergy.html
35 ft/lbs is more than 1 3/8 oz. 3 3/4 Dr. Eq. (1295 fps) in an 8# gun at 32.6 ft/lbs
And BTW: my aforementioned 2 3/8" chambered 20g had a crack in the wrist that required repair |
I like it. Good stuff. I did not see your free calculator. Btw sorry to hear about the 20 broken at the wrist. Do you know why it broke. I saw a gun with a broken wrist after a fall, not certain I have heard of a broken wrist on a shotgun from just recoil.
I found a recoil calculator that was on a rifle webpage and then had to to convert ounces to grains and drams to grains. I think I came out about the same as yours but I also played with 2 3/4 drams of powder for a 1 ounce load and foot pounds went up. As follows is exercise I went thru. Will put same variables in the link you provided to see if its different. Lots of variables to consider to get different outcomes.
Okay. I found a shooters recoil formula. Calculator is setup for rifles but it should calculate out the same. Had to convert grains to drams and ounces of powder and shot. I ounce of shot is 437.5 grains and 2.5 drams of powder is 68.36 grains of powder. Looking at Bruce's table for my 16 Gauge I used a 7lb weight for the gun. With these inputs it calculates out at 32.85 foot lbs for the federal load.
Since I/we don't know how much powder is used in the RST loads then its hard to calculate the differences. But its an interesting point. If the charges are all the same just put in 1200 fps for the RST loads and keep then recoil energy goes up to 34.4 lbs. Then the recoil energy is less for the Federals by 2 lbs, thereabout. That is only about 4.5% difference and maybe negligible due to certain vagaries.
For giggles went and calculated what an 8 pound 12 gauge would produce at 1200 fps, 3.5 drams 1 1/8 ounce load. That recoil is 45 lbs. That is a 28% increase. If gun frame is about the same on a 12 to 16 gauge Parker and assuming wood is about same thickness, that is about 10 or more extra pounds being exerted on the stock. That might be the difference in whether old american walnut splitting out, or not.
http://www.shooterscalculator.com/recoil-calculator.php