Could you explain to me the benefits though?
As far as I see it I’d want to verify the drop anyway.
It all depends what you want from your experience.
If you just want a hunting load that you know will hit the target zone reliably at stalking ranges (let's be brave and mention up to 250 yards) then all you really need to know is that your load is deer legal in terms of energy and as you already have done, determine what the round is doing from your chosen zero, so nominally every 25 yards from zero to let's say 300 yards. It really doesn't
need to be more complicated than that. You can do that in a 300 yard field with a backstop and a notebook.
However, a lot of folk load for accuracy, and because..... well, because we can!
I have a number of reasons to load accurate rounds, and none of them really affect what I'm doing when stalking under normal circumstances.
I'll try and explain what I mean. I shoot the same rifle at deer, foxes, paper and steel targets out to 1000 yards plus. Generally speaking I won't be shooting at deer much over 200 yards and foxes out to say 300 in the right circumstances. It's simple enough to load up a round that will do that and be consistent enough to group reliably within 1/2 to 1 MOA. Margins for error taken into account, a centre mass body shot on a fox or a broadside chest shot on a deer is pretty much taken care of from 50 to 200 yards.
BUT, this where knowing your exact MV comes into play so you can use a ballistic app to predict the round's trajectory. I like to work with a point blank range principle. Point blank is a default range where you can be sure of putting a bullet in a 4 inch circle without changing your point of aim or adjusting your crosshairs/turrets of whatever. In other words wherever you put the crosshairs, the round won't go any higher than 2 inches above the crosshairs, or any lower than 2 inches below. It's of great benefit to stalkers or fox shooters because it means that as long as you know what "too far " looks like, you simply aim and shoot. To determine what this range is, you need to know the approximate trajectory of your round for a given aim point. Yes, you can do this with the 300 yard field and notebook method, but to get the most out of the principle it would take many many rounds of practice to get it spot on.
That pointblank changes with where you zero your rifle. A round zeroed at 100 yards will drop significantly more at 200 yards than one zeroed at 50 yards, and a round zeroed at 50 yards will hit high at 100 yards. A round zeroed at 50 yards will also have a secondary zero point somewhere between 100 and 200 yards or possibly even further if you're shooting a fast flat round. This is all well and good, but you need to be able to fine tune it to make sure the round isn't striking too high at an intermediate distance between the two zeros. The principle fails if your curve is so steep that it's hitting more than say 2" above POA at 100 and the round only groups more than say 1 MOA...... you'll be shooting above the 4" circle. You can alter the behaviour of that curve by changing the zero range of your rifle. The closer you zero, the higher the round will be at 100-150 yards, the further away you zero, the greater the drop will be at 200.
Take my .308 as an example. It's zeroed at 40 yards, to give a max trajectory of 1.5MOA high at 100 and is back on zero at 180 yards. It drops 1.5 inches low at 200. The load I developed for it is pretty slow, not much more than 2400 fps, but is nice and accurate, grouping 1/2 MOA at 100 yards. It's a loopy round, but is still point and kill out to 200 yards. Zeroed at 50 yards it was only about 1/2 high at 100 and 2.5 inches low at 200. SO still point and kill, but only out to 175 yards or thereabouts.
That trajectory curve can be exploited by whichever method you use, but by far the easiest way is to input the known variables accurately into a ballistic calculator, so, bullet weight, BC, scope height, and most importantly muzzle velocity. Once you know that you can reasonably accurately predict where the best zero range is going to be for he longest usable point blank.
Using a chrono also helps to develop a load which will group accurately to start with, but that's for another time perhaps.
