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Location: Southern NH
Joined: 09/13/2006
Posts: 379
Free Recoil Energy

OK, now I'm a bit confused and I need to show my ignorance a little. The thread comparing the .270 Win to the .280 Rem stated that the .270 Win, with factory ammo, kicks more than the .280 Rem with factory loads. For sake of discussion let's assume that both guns weight the same and are both shooting a 140 grain bullet. Comparing ballistics charts from various manufacturers and using plain jane ammo, not the premium or HE stuff, I see that the .280 Rem has a slightly higher energy at the muzzle. I make the assumption that it either has a tad bit more powder or its case design is a tad bit more efficient. Would the .270 have more felt recoil? Remember that the rifles weight the same and the projectiles weight the same. The .280 is going a teeny bit faster (more kinetic energy) so shouldn't the felt recoil be a teeny bit higher? Newton says it's getting it's velocity from somewhere (the weight of the gun and your shoulder). I am splitting hairs here because I think the cartridges are almost the same. Help me understand this. Think Once I understand this and the whole uphill/downhill holdover/under thing I've got this shooting thing licked. Evil!

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Location: Summit, IL
Joined: 10/22/2006
Posts: 706
Free Recoil Energy

hehehe Yeah Its wierd....But the 2 that I shot (one TC Pro Hunter and one Rem 700 cdl) Both seemed gentler then my 270 cdl....Now I would expect this with the new Pro Hunter because of the flextech stock but It really did surprise me with the cdl. I would assume from basic physics that the 280 would kick harder but it didnt least not to me anyway...there wasnt that much difference...Hell maybe I was having one of those wierd days. Never know

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Location: Southern NH
Joined: 09/13/2006
Posts: 379
felt vs. free

I think I know where I'm getting confused. Free recoil vs. felt recoil. Free recoil takes into account powder charge weight and gas velocity. Felt recoil doesn't have any scientific formula to calculate it. It's strictly "seat of the pants" ....or is it "seat of the shoulder" or "shoulder of the pants". Anyhow, if you do something to reduce the free recoil energy of your gun, felt recoil should go down also. If you took the same two guns in .270 and .280, shooting the same weight bullet and the .280 has more velocity, it would have slightly more felt recoil than the .270 if there wasn't a big difference in powder charge and the two guns weight the same. This would be due to the higher kinetic energy due to the faster bullet at the same bullet weight. OK, I think I got it. Now if I'm shooting uphill at a 45 degree angle do I aim above or below my target. Below....NO!.. above...wait a minute...... Laugh

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Moderator
Joined: 12/03/2005
Posts: 1691
Free Recoil Energy

The ft/lb energy is not used in the calculation. Here a Free Energy Recoil calculator for you(no sifferin needed). I use 150 gr bullet,57.8 gr powder,3150 fps, rifle9.5 lbs if I remember, and my Free Energy Recoil will probably be a question on the final exam??????

http://www.huntamerica.com/recoil_calculator/

I'll try to find something about your uphill shooting question but in the meantime shoot at the target
Found what I was looking for:

http://www.exteriorballistics.com/ebexplained/5th/33.cfm