22 250 ballistics help

[Sharpie]

Hi James.
I have a Drone pro on my 22-250, this sits at 2.6" high off the bore, because the scope is higher than normal this will give a further secondary zero.
I use home loaded Nosler 50g bt's and estimate their speed to be doing around 3570 feet per second, i initially zeroed mine at 1" high at 100yds, but i was finding that shooting foxes at a typical 150 yds a lot of my shots were going too high so i lowered the Drone Pro two clicks ----or there abouts, since then iv'e been hitting most cleanly from 50yds -240 yds aiming dead on, i dont really need to shoot foxes much over this distance so cannot really comment on drop/hold over past 240 yds.
Most centre fire rifles are at their highest point in trajectory at around 150 yds, therefore IMO you dont want to be "ANY MORE" than 1" high at 150 yds because if you aim just a little bit too high or pull the shot a little high you'll be going over the top of the fox like i was.
The Drone Pro adjusts owt from 1/2"-3/4" per click so you've to adjust to the nearest click to suite, check your rifle at 150 yds and adjust to the nearest click to give you not more than 1", this is what i've got and its point-n-shoot out to 240 yds.

Dave (warbucks)

Useful data recording Drone pro scope height 2.6". This high axis above boreline changes everything.

Lets see, Hornady 22-250 Rem 55 gr V-MAX. Muzzle velocity 3680 fps (from a 24" barrel.)
Hornady 55 gr Vmax .224 , no. 22271. BC (G1) = 0.255

Put numbers into ShootersCalculator.com

Hi all i am running a 22250 rem with a drone pro and I have just changed to factory vmax 55gr. Went out to zero new round yesterday. I was an inch high at 100yds but 2.25 high at 150yds. Looking at the balistics chart for that round it shouldn't be going there. Any ideas or is it just me being thick ?

If, instead of zeroing an inch high at 100 yards (why ?) you had zeroed exactly at 100 yards, you would be pretty much flat out to over 200 yards. Primary zero would be 175 yards. That's where you should refine the zeroing, after starting at 100. Actually you could tweak things to be better. It would always be shooting a little low except at 100 and 175 yards. You could tweak it so you extended your MPBR by letting it rise a bit inbetween zero distances.

If you chrono your MV in your rifle, with your barrel length if less than 24". If it is 24" and no chrono, then just accept the Hornady published MV.




Hope that helps. Took me ten minutes altogether to work it out.

As the others have said, start by zeroing properly at 100 yards. Then take it from there.

 

[Sharpie]

Just put it bang on at 100 yards because by your figures you won’t be to far away at 200 yards. Just shoot it because 200yards to 230 yards at night it a long way so don’t over think it just enjoy it. The vmax is a great bullet but I must admit I prefer the 53grn vmax to the 55 grn vmax

Good advice, in general, for flat shooting chamberings. I.e. start at 100 yards. Then do it properly at 200. Doesn't quite work though in this special case (very high 'scope) where primary zero seems to be more like 175 yards.

But, guess what, if you set the perfect zero to be 200 yards (0.26" high at 100, if you think you can measure that), then you will be flat, (within an inch) beyond 225 yards.


Pay attention to the windage though, this soon begins to bite with low BC things like 55gr .224 bullets. The table is just for a 10 mph crosswind, which is not a lot really.

 

[Sharpie]

Same here, zero my 22-250 (20") 0.75" high at 100 yds, bang on at 200yds, shoot dead centre all the way out to 240yds on fox sized target. Even switching between 50 & 55gr makes virtually no difference at 200 yds.

Yes that probably works just fine for a normal scope height. Maybe 1.75" You are spot on with those numbers.

Calculators are pretty useless unless you have good quality data and MV for that rifle and load… in fact even then you often need to true the data a little by testing it at various ranges. There are simply so many variables that affect a bullet flight it’s mind blowing. My advice is do a dead on zero at 100m then drop test to 350m or further if you can. The you will know something…

I think you are being a bit dismissive. If, I agree, you can get some good data, specifically the bullet BC, and the, MV, preferably from a chrono in your rifle, external ballistics calculators can get you quite close. If say tests at 100 and 200 yards match well when tested, then you can be reasonably confident. Stretching out to 350m is more relevant to those who do shoot that far, and way beyond.

 

[James Todd]

Great info thankyou to all posters...makes a lot of sense

 

[Utectok]

Yes that probably works just fine for a normal scope height. Maybe 1.75" You are spot on with those numbers.

View attachment 270439


I think you are being a bit dismissive. If, I agree, you can get some good data, specifically the bullet BC, and the, MV, preferably from a chrono in your rifle, external ballistics calculators can get you quite close. If say tests at 100 and 200 yards match well when tested, then you can be reasonably confident. Stretching out to 350m is more relevant to those who do shoot that far, and way beyond.

Fair point at those ranges it’s probably fine with MV and bc

 

[Len the dog]

FWIW, the chrono velocity for my 20” 1:14 Tikka T3X for Hornady 55gr was 3498 at the muzzle. I’m looking at a loss of between 150 & 200 fps from 24” book velocities of various factory ammo.
Not a problem as there’s still more than enough oomph and it handles like a dream.

 

[Sharpie]

Fair point at those ranges it’s probably fine with MV and bc

It is also handy to look at calculators if you are a dialler with a rangefinder. E.g. in the example above (normal sort of scope height), assuming 1/4 MOA turrets, after zeroing at 200 yards, you could have a drop table something like, 3 clicks low at 100, yards, 2 low at 150, 0 at 200, 3 high at 250, 6 at 300.

This knowledge also helps when shooting the 100 yard zero. Do so using 3 clicks low. Saves you trying to estimate whether your group is really 0.78" above the centre of the target. Then unwind the clicks for the 200 yard proper zero.

Then you could go out and test your drops of course.

 

[Utectok]

It is also handy to look at calculators if you are a dialler with a rangefinder. E.g. in the example above (normal sort of scope height), assuming 1/4 MOA turrets, after zeroing at 200 yards, you could have a drop table something like, 3 clicks low at 100, yards, 2 low at 150, 0 at 200, 3 high at 250, 6 at 300.

This knowledge also helps when shooting the 100 yard zero. Do so using 3 clicks low. Saves you trying to estimate whether your group is really 0.78" above the centre of the target. Then unwind the clicks for the 200 yard proper zero.

Then you could go out and test your drops of course.

Good idea although going down is a pain with a zero stop turret