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1 minute ago, London Best said:

A clever person could work out the residual energy left in a 40 grain .22 bullet fired vertically at 1050 FPS when it returns to ground. 
I’m not clever enough, but I’m not stupid enough to fire one vertically and stand under it either!

Neither am I; by the time they’ve punched their way through the young rook they’re deformed to a greater or lesser extent I imagine, and pretty well spent. Either way, each to their own. 👍

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Technically the initial upwards velocity will (alongside BC etc) determine the height at the apogee. From the instantaneous moment that the projectile is motionless (assuming 90° angle and no wind) it will start falling, accelerating towards the ground faster and faster until it reaches its terminal velocity. It depends as to whether the terminal velocity in free fall is already reached in the fall as to if an increase in velocity leaving the gun will correspond to an increase in speed of the projectile upon impact with the ground.
 

But for any projectile from a standard firearm at normal speed I would imagine that you are correct in practice. 

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About 30 years ago myself & a relative were asked to deal with problem rooks in the grounds of a country house hotel,the rookery was in a stand of pine trees & was well established,growing year upon year until it got too big to ignore,the noise & the amount of cr#p being constantly splattered all over the buildings & guests vehicles got to a level where it was affecting business so action had to be taken,our first outing was in time for the branchers,a good majority of them were dealt with using air rifles,afterwards,any that had made it back into the nests & quite a number of adult birds circling above the trees were dealt with using a Marlin goose gun & Baikal Record cartridges!,the rookery was considerably reduced in size by the end of the day,pollarding trees with a shotgun,sore on the neck & shoulder but bloody effective! 🤣🤣🤣

Edited by 51/50
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I shot 10 bells out of a bunch of nests last year just before branching time.

I checked it out again about a week ago while walking the dog and there is no sign there were ever any nests there. The rooks have moved to a new location a few hundred yards away and appear to have taken what was left of their nests for building materials unless high winds finished them off.

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i shot branchers as a lad first with catapults then air rifles slug guns we called them then would still do it now if needed to how ever rooks in my area have had a massive decline in the 50 years ive been shooting so i for one will leave them alone 

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On 05/04/2020 at 22:18, London Best said:

A clever person could work out the residual energy left in a 40 grain .22 bullet fired vertically at 1050 FPS when it returns to ground. 
I’m not clever enough, but I’m not stupid enough to fire one vertically and stand under it either!

The residual energy would be around 2.25ft lb.

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Just now, London Best said:

I am going to have to take your word for that!

Out of interest, could you post the maths please?

Terminal falling velocity taking air resistance into consideration 160fps. 160 x 160 x 40 divided by 450240 converts to energy in ft lbs. Atmospherics would have some effect, so this would be a close but not exact figure.

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20 minutes ago, Rimfireboy said:

Terminal falling velocity taking air resistance into consideration 160fps. 160 x 160 x 40 divided by 450240 converts to energy in ft lbs. Atmospherics would have some effect, so this would be a close but not exact figure.

Ah, but the round isn’t in free fall, it’s either in the rook or has deformed on its way through. 👍

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Not if you missed Scully.  Surely you do sometimes?

1 hour ago, Rimfireboy said:

Terminal falling velocity taking air resistance into consideration 160fps. 160 x 160 x 40 divided by 450240 converts to energy in ft lbs. Atmospherics would have some effect, so this would be a close but not exact figure.

Rimfireboy, thanks for that. The bit I couldn’t work out was the terminal velocity, how does that compute?

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34 minutes ago, London Best said:

Not if you missed Scully.  Surely you do sometimes?

 

Can’t ever recall missing a Rook; perhaps a rabbit now and again when I’ve been chancing my arm at longer ranges, but if you get set up properly then it shouldn’t happen. I don’t shoot branchers with a rifle in any sort of wind or even a stiff breeze as it’s nigh on impossible, in that case I’d take a shotgun. 
 

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7 hours ago, London Best said:

Not if you missed Scully.  Surely you do sometimes?

Rimfireboy, thanks for that. The bit I couldn’t work out was the terminal velocity, how does that compute?

Different objects may fall at different speeds, but taking air resistance into consideration and depending on the shape and size of the falling object, this would be on average 49 mtrs/second .A smaller heavier object may fall faster than a larger and lighter object of course. This may be explained in more detail by looking into equations of a falling body, further information on this subject is available on the internet.

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