semi auto or pump for geese

[billd]

does anyone know if a semi auto takes away any energy from the shot vs a pump  does the cycling of the action use up some of the performance  when using the same loads . thanks

[mcwoodduck]

The short answer is not enough to matter.
The long answer is:
It would depend on the type of action.
Gas, inertia, or blow back.
Gas - bleeds off a little gas to cycle the action.
Inertia - pushes the bolt back
Blow back is like the browning Auto 5 system where the whole barrel goes into the action.
All types bleed off a fraction of the shot energy to function the gun.
Is it enough to matter?  no. 5 to 10 FPS at most.  Same as shooting a 28" barrel out of one and a 27 or 26" out of the other.  5 FPS per 1" of barrel.
If you are worried about energy i would look to the heavier than lead products.  Tungston Iron, bizmouth, or Heavy shot.
The few snow and barnicle geese I have shot with the 3" Heavy Shot #2's out of my guns have worked well out of my Pump gun and friends autos.  Had no problem dropping them at distances freinds thought was too far. 

[Specklebelly]

Go with the auto, the rapid fire makes up for the minimal loss of velocity.

[JRSpicer426]

If your talking gas operated, your going to loose virtually no shot speed. In a interia driven gun, the shot has physically exited the barrel before the bold unlocks and cycles. If you want velocity jack up steel speeds. If you want energy over speed, go hevishot.

FWIW, I use a pump for ducks and semi for geese. The pump slows me down for the ducks, and the semi is ready for double taps on hovering geese

[dukkillr]

If you are serious about waterfowl hunting, particularly bad weather and rough conditions,  you'll want a pump.  If it's going to be a September field hunt once or twice a year it probably doesn't matter much. 

You will not lose any shell performance with an auto but I've always suspected an auto makes you less accurate.  My theory is based on the fact that with a pump there is a timing to the shots that forces you to re-address your target.  Simply put, you can't just pull the trigger again and make the same mistake you made on the shot before.  Of course I have absolutely no science behind this, it's just my observations from personal experience and being around others.