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If you were to bore sight your shotguns ((exact bore centerline)), use that pre-determined mark at 10-20 or 30 yards, where would the center of the patterns strike in relation to that new aiming spot? Both fast and slow loads?

Hap

Muzzle rise occurs only after the ballistic load (the shot) leaves the barrel.

Keller

Keller

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Put it on the pattern board.

Average of 30-32 yards is 31 yards or 93 feet.

A 1290 fps load is traveling at 1,290 feet per second

An 1145 fps load is traveling at 1,145 feet per second

If you divide 93 (feet) by 1,190 you get .072 seconds for the shot to travel the 93 feet.

If you divide 93 by 1145 you get .081 seconds for the shot to travel the 93 feet.

.081 seconds - .072 seconds = .009 seconds between the speeds of the 2 loads to travel the 93 feet.

I find it hard to believe that 9/1000 of a second makes much difference.

Your hits are lower, why would you want to decrease your POI? Raise your POI so your hits will be higher and thus be centered on the target. HMB

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BigBad, wouldn't wind resistance play a role?

Unknown: Interesting point. Why does a barrell rise anyway?

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If your shooting at 25 yards and think... "my current load is a little high. I'll go slower and the bullet will hit lower" doesn't work. The slower shot will be even higher. A high velocity round will impact somewhat lower. Strange, but true.

Does that apply to shotguns? I really don't know. But it may be so at a certain distance.

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What Tom said.

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Gary Bryant

Dr.longshot

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Think about it. How is the target supposed to know where the pellets that don't hit it are and so be able to respond "in conformance to theory?"

Neil

LMAO...

Brownk80

BigBad Bob, while you have your calculator warmed up, how far did the bird move vertically in that 9/1000"s of a second?

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Though BBB didn't account for the drop in speed of both loads, his estimate of the difference in time to get to the bird at 30 yards is very close. Shotgun Ballistics for Windows says 0.0087 seconds but we will use his 0.01 for convenience.

Pat Ireland and I, using different radar guns, both estimated the speed of targets when they were smoked (and so the radar gun stopped seeing them) was close to 30-plus miles an hour, call it 45 feet per second.

So in a tenth of a second the bird flies 4.5 feet and in 0.01 second it flies 0.4 feet. But that's the speed it leaves the shooter and not the rise, which

we will say is based on a flight-angle of ten degrees, half-way between the start of 20 degrees and the eventually flattening out. The rise is the opposite/adjacent of the resulting triangle and that's the tangent and the tangent of 10 degrees is about 0.2 so the rise is about 0.2 times 0.4 feet giving a linear rise difference of about 8/100 of a foot, call it an inch.

That’s more of a difference than really occurs, of course, since the bird is not the only thing that's rising, the shot is too. The effect is to reduce differences like this, but not much and it depends on the height of the shooter but let's not worry overmuch about that.

My view is that

1. You can't read target breaks for the location of the shot at all at all, not once and

2. Even if you could, the difference Phil thinks he is looking at is less than about an inch and so I think he's imagining it.

That’s the problem with target-break reading. It looks like it works though it doesn't and tricks you into seeing all kinds of other things which aren't true either. The only defense is to quit doing it. If you can't do it alone, there's probably a TBRA meeting in your area to offer support. With help from the whole TBRA community, you can beat this thing!

Neil

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