there are a number of things needed to get a round down range.
To get accurate range card data you need environmentals that might be different between your Zeroing environmentals and when you‘re actually using the the card info. for this reason I prefer a smart phone app like shooter but that’s just me. As you increase the distance of your target, the impact on environmental changes tends to have more influence on bullet flight.
Other factors, G1 BC generally not used as G7 BC is generally used for boat tail bullets which are most often used in LD shooting. Also most BC’s advertised by bullet manufactures are sometimes a bit overstated, based on testing performed by an independent lab. There was an article written by Air Force Academy students that outlined this fact. The article was removed from the web due to pressure from bullet manufacturers who were not happy with the finding.
Applied Ballistics has a catalogue called Ballistic Performance of Rifle Bullets. I have the 3rd edition published in 2017 which is a bit dated, but it is still a great resource. it has detailed ballistic data on quite a number of bullet manufacturers in different calibers as well as bullet weights. Accurate BC is again another important factor in determining an accurate range card.
last but certainly not least you need to give a range card or ballistic calculator an accurate muzzle velocity of your bullet. You can’t count on the advertised bullet speed in a reloading manual or on the outside of a box of factory ammo because that bullet speed would very heavily depending on the rifle barrel length and other factors inherent to each individual weapon. For this reason a chronograph is incredibly important I use a magneto speed V3 and that and the other resources I use include shooter and my BC catalog give me some pretty accurate range cards on my shooter ap. Back when I was shooting my 308 I memorized my range card out to 500 yards simply because in general I was shooting my 308 within an average range of about 10 to 15° for my 175SMK
100 Zero
200. .5
300. 1.1
400. 2.1
500. 3.2
these numbers inside these ranges remained pretty consistent and actually a bit boring until I started getting out to 1000 then 20° temperature changes coupled with humidity changes did caused me to miss my target. So to measure humidity and temp and all that during my zeroing process which you input to your ap as a baseline which goes into my shooter app as well as during normal firing condition Environmentals during my range sessions I made use of a Kestral that interfaces with my cell phone Via Bluetooth and basically update everything automatically In my more expensive Applied Ballistics phone ap..
all the above presupposes that you have tight groups at 100 otherwise unless you’re shooting at a barn wall, the best range car in the world won’t let you hit anything reasonably sized at distance.