POI at Highest point..

WhelanLad

WhelanLad

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Hey gurus,
roughly, saying with a +1 and +2 inch POI at 100m, where is roughly the highest point of the Arc?

around a 2800fps Start point. 120Grains.



I freshly ran patches through my Barrel on the Kimber 708 , then shot two shots to get them out of the way before a Hunt, at 170meters they both printed almost touching ..............

the only issue was its 4 inches high, or close too..... Sound Right?

and the POI is 2 inches high at the 100m range..... confirmed just today..


I know sometimes a shot or two can foul the barrel an bring it back down to a sighted poi, but I do also kno that guns vary an some do infact like it clean... we have discussed this as my old Tikka couldn't do a group after 30 shots but touched em when cleaned.....


I suppose I need to crunch numbers into that blody ballistic calculator don't it...?
 
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No, it doesn't make sense; based on the velocity given. Speaking of
velocity, why so slow?

Two shots out of a clean gun are better than nothing, but not much better. You're going to have to burn some
powder to even get reliable observations, never mind any kind of conclusions.
 
Read up on Maximum Point Blank Range. You might find your answers there.

AFAIR (because that was 20yrs ago), MPBR was a topic one American gun magazine writer promoted. The idea was to zero the rifle to hit within an arc only as tall as the game animal's body mass. So the rising trajectory was no more than the back, and the the trajectory below the point of aim was within the breastbone. The POI was therefore probably two-thirds down the body. Hold lower for close shots, hold higher for distance, but only shoot at the actual animal.
 
WhelanLad said:
Hey gurus,
roughly, saying with a +1 and +2 inch POI at 100m, where is roughly the highest point of the Arc?

around a 2800fps Start point. 120Grains.



I freshly ran patches through my Barrel on the Kimber 708 , then shot two shots to get them out of the way before a Hunt, at 170meters they both printed almost touching ..............

the only issue was its 4 inches high, or close too..... Sound Right?

and the POI is 2 inches high at the 100m range..... confirmed just today..


I know sometimes a shot or two can foul the barrel an bring it back down to a sighted poi, but I do also kno that guns vary an some do infact like it clean... we have discussed this as my old Tikka couldn't do a group after 30 shots but touched em when cleaned.....


I suppose I need to crunch numbers into that blody ballistic calculator don't it...?
Click to expand...

Yes it do. Real numbers will be the only way to get real answers.
 
Your results would make sense if you were sighted 3 - 3¼" high at 100, not 2" Something is amiss there.
Are those results repeatable? If so you have a clean barrel that throws shots. I had a 30-06 that did that,
hitting exactly 2" higher at 100 with the first shot from a cold, clean barrel. All subsequent shots were good. D.
 
If you look at online Ballistic calculators, Federal etc. , you should be able to pick a bullet and velocity that approximates what you have. It will show the maximum rise on a graph.
 
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