ok all you math wizards

[Magwa]

Ok so i do not have a 100 yard shooting target in my yard with out driving aways away so io set up a 40 yard target shooting 168HPBT and i figure my scope is 2.5 inches above the bore so I figured about 3/4 of a inch low puts me dead on at 100 hows that sound to you guys> 16 inch barrel 2650 FTS 168 HPBT.....

[Goofball310]

I might be way off but I'm getting around -1.25" since the bullet is still on a its most linear path and won't have drop off til after 100 yards.

[unforgiven]

I think I set 2" above bull @ 25 yrds. ,went to 100 yrds. and dialed in from there.

[washguy]

I think I set 2" above bull @ 25 yrds. ,went to 100 yrds. and dialed in from there.

Brother Rene is right on for 25 :) at 50yds you wanna be 2" below roughly with 168 done it many times at an indoor 50 yd range :) Wash

[Magwa]

Ok so let me get this right at 25 you want to be 2 inches high and at 50 2 inches low HMMMMM something is not right here so I will go with 1 and 1/2 low at 40 yards since the bullet is still rising..... how about that?

[washguy]

that will do it....pretty close I would think....but I aint gonna stand out there with an apple on my head !

:) Wash

[seasprite]

Alright first thing is whats your barrel length and is this factory or hand loads did you chronograph the loads? The reason I ask is barrel length makes a difference in velocity if your reading it off a box of factory ammo, the test barrels typically run 20"-24". If your running a 16" barrel there is no way your getting 2650 fps from factory loads but you might from a warm hand load ( ask me how I know ::) ) If they used a 20" test barrel and got an average of 2650 your probably only getting 2550 from an 16" barrel, its common to knock off 25 fps per inch shorter your barrel is compared to the test barrel.

 

I just finished using an chronograph for my 168 gr A-max hand loads and they run 2575 out of my 16" barrel DPMS rifle I then went to Hornady web site and used there ballistics calculator and came up with this. Hope it helps.

 

 Ballistics Calculator - Hornady Manufacturing, Inc.pdf 

Edited October 9, 2013 by seasprite

[shibiwan]

How about these at 200m zero? Just do the math to correct for a 100m zero

 

FGMM168SMK.pdf

FGMM175SMK.pdf

 

[Magwa]

Ok looks like according to these charts I am right in the ball park if the bullet is -1.3 at 25 and -0.5 at 50 then my calculation of -0.75 is pretty close at 40 yards... BTW the barrel is 16 as stated in the first post at the end the round is a factory barnes ttsx 168 they are know as pretty warm and I just guessed at the 2650 I am finr with 2550 and I know the elk will never know the difference... thank you gentlemen for the help :)

Edited October 9, 2013 by Magwa