•••for you ballistician/calculus types•••?

[the Black Spot]

7.5" barrel,
44 caliber
315 gr cast bullet
700 fps
line of sight -.75"
4" high at 25 yds
What is my point of impact down range and the fps?
What yardage would be my highest midrange trajectory?

 

[Fine Figure of a Man]

You didn't list the caliber and the barrel length is irrelevant.
Go to JBM Ballistics, enter the data and you will have your answer.
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

 

[badkarmamib]

Zeroed for 73 yards, apex 4.7" @ 39 yards. 650.63 FPS w/ 296 ft-lbs at 73 yards. Shooting Solution Free is a great app.

 

[the Black Spot]

Fixed it

 

[Archie]

My testing shows substantial variations firing the same (factory) load from two of the 'same' guns. I have an old carbine which shoots two hundred fps (more or less) than a rifle of the same sort.

I am skeptical of predicting velocities as you outline. None of mine seem to work as expected. You might have more encouraging results. I'd still suggest a chronograph of some sort.

 

[Fine Figure of a Man]

I am skeptical of predicting velocities as you outline.

The OP is asking for the trajectory of a specific bullet at a known velocity.

 

[Toprudder]

7.5" barrel,
44 caliber
315 gr cast bullet
700 fps
line of sight -.75"
4" high at 25 yds
What is my point of impact down range and the fps?
What yardage would be my highest midrange trajectory?

Not enough information there to answer the question. At the very least the BC (ballistic coefficient) for the projectile would need to be known. Not having the sights zeroed at a particular range is also a problem. If you figure out the BC for your bullet, you can go to the link that @Fine Figure of a Man linked to and enter all the variables. Keep changing the zero distance until you have 4" high at 25 yards and then you should be pretty close on trajectory.

 

[jmorris]

Some of your supplied information makes no difference to the calculations and you are missing one of the more important pieces, ballistic coefficient.

Here is a decent guess though.

 

[the Black Spot]

Thanks for all the input.
Not sure what the BC would be for that bullet(lee mold 310-430)

 

[Toprudder]

Found this:

https://www.titanreloading.com/ballistics-questions/ballistic-coefficients-on-molds

They list the C430-310 at a BC of .218 (so @jmorris was pretty close at .220)

 

[the Black Spot]

This has really helped, thanks!