When to go bigger?

I have an opportunity to shoot out to 700 yrds coming up. Have never had a range longer than 200. I have moulds for the Lyman 457125 round nose 500 gr. & the Lyman 457132 semi-pointed 535 gr.
They both seem to shoot well at the ranges I'm able to shoot, but was wondering when or where does the round nose start to "fade" whereas the pointed one keep shining? Or is it a moot question at a meer 700 yrds?
I would guess I should shoot them both, and probably will, if time permits. Just wondering what one might expect.
45-70, 70gr Goex FFG,20-1 alloy,SPG,.125 cardboard wad.

Knarley

the postel bullet was the premier bullet for many years for target shooting , the round nose will work just as well but will take a little more elevation, either one will do the job quite well with the nod going to the "pointier" one

Postel will ride the wind better.
The round nose is a killing bullet.
LG

The postell bullet performs well at mid to long range very well. The round nose has a good reputation for accuracy but may not be as easy t read wind for. If possible shoot both and make note of the diffrences as to wind, sight settings, accuracy and other informations. Keep in mind each rifle load combination is diffrent and unto its own. Predicting a bullets performance isnt always that easy.

Powderburner gives good advice, it is always good to pay heed to his few words.
The fella that won all the banana's in the midrange event at the bptr nationals last year shot the postel in his 45-70.

I've used the 535 Postel in the 45/90 @ the Quigley to get an "8" pin on the 800 yd. buffalo, twice :bigsmyl2: