[nonnieselman]

Ok so ive made a mental notebook of the Ballistics of my .270 .

140gr Berger VLD

100 4"
200 9"
300 0"
400 -3"
500 -18
700 -50.4"
(edited for correct numbers)

Shooting at a 20" Gong so those numbers are a rough trajectory. I aimed for center and add or subtract depending on the hit.

The bullet is on its way down pretty fast right now so im tryin to guess for my 1000yd shot and then walk the target out to 800, 900 and then see how far off i was on my 1000yd guess.

I was very suprised at how much the wind didnt affect the bullet at 700, we had a slight 5mph wind from 11 oclock and the target had a slight 5mph wind from 9 oclock.

 

[X-Ring]

I don't have the link here at work but I think it is jbmballistics.com
And they have a good trajectory program to run online that has always gave me pretty good comeups and wind drift.

 

[nonnieselman]

Ive tried that one and a few more and none of them are even close to what im actually getting while shooting.
Only thing im sure of is my bullet weight and BC, and the above trajectory.

Hope to get a Chrono here soon so i can see what its doin speed wise but im not getting any pressure signs and im on my 3rd reload with these casings. plus another 3 or 4 of them being light loaded in the same rifle.

 

[nonnieselman]

Here is what i cant understand...

Im holding over 2MIL at 700yds, everything im reading is saying its gonna drop 80-90" at that distance. holding 1 MIL over at 500 it says its gonna drop 20-26".

I have confused myself but doesnt 1 MIL = 3.6MOA? (edited for 3.6moa instead of 3.4moa)
7.2MOA at 700yds is 50.4"

 

[X-Ring]

Yes you are right about the MIL for 700 yards. Generally JBM has always been pretty accurate for me within a 1/2 to 3/4 MOA and I always credited that differance from either the barometric pressure elevation or temperature not being the same. Not having a good chrono reading on your load is probably where the differance is coming from. Also make sure of your sight height above the bore and enter it.

 

[nonnieselman]

Gotta measure that too.. i went all the way up to 2.25" and its still way off... Im gonna start figureing everything out one day :lol3:

I even jacked the FPS up to 3000 and its off.. i dont think ill be able to push a 140gr VLD that fast without pressure problems.. Guess we will see.

This factory SPS pencil barrel heats up really fast!

I need to go ahead and sight it in for 600 and try to shoot with you guys in the match.

 

[X-Ring]

Come on down, we will be glad to have you. I think you are close enough to get on paper with your 1st shot so you can tune that bad boy into the X and run a clean target from there.

 

[nonnieselman]

Found out my problem.
:suspect:

For some dumb reason i was thinking i was holding over .5MIL where i was actually holding over 1MIL... That kinda throws off the calculations :blol:

The Mil DotBar is the reticle im using.

 

[nonnieselman]

measured my scope height last night and its 1.5", Now hopefully this weekend i can run it thru a chrono and get one more peice of the puzzle solved.

 

[GunOneDown]

Jonathan, Have you ever checked out a program called Bullet Flight?
They have APPS for your phone and computer if it has GPS. I've seen these used by military. they even offer a mount for your rifle to have a smart phone right there to look at and pull data.
Just a thought...........

 

[nonnieselman]

Jonathan, Have you ever checked out a program called Bullet Flight?
They have APPS for your phone and computer if it has GPS. I've seen these used by military. they even offer a mount for your rifle to have a smart phone right there to look at and pull data.
Just a thought...........

I have a dumb phone, its a motorola Tundra. Tough son of a gun but i doubt anything like that is available for it.. ill start looking.