zero range

[emp1953]

I tried with two different ballistic apps. I fiddled with input data until I came up with a result that was close to my real world results. Adjusting the MV and the scope height brought trajectory results pretty close to what I got at the range on paper.

 

[Sdvldog1371]

I'm looking at ballistics charts to determine my zero range for my B-14 HMR 300 Win Mag. Seems like it doesn't make too much of a difference whether its 100 or 200 yds. I just plugged in some numbers using a .484 BC and 3025 MV for a 180 gr bullet. At 1000 and 1500 yds the elevation adjustment in MOA for 100 yd zero and 27.6 and 63.2. The adjustment with a 200 yd zero is 26.5 and 62 MOA.
I believe I can be more precise zeroing at 100. What say you gentlemen (and ladies).

I say why even bother zeroing beyond 100? It's not like you're that far off target at 200 if you just use your 100 yd zero.

 

[LRNut]

I have the opportunity to shoot out to 750 in practice. I will make up a long target say 96inches of butcher paper on a frame, shoot a group of 5 at 100, then let things cool down repeating the process at 100 yard intervals. It usually takes about 5 hours to get this done. When finished I have a real world ballistics chart. No ballistic app I tried duplicated my real world results. 100 to 200 was close but then results diverged. I'm sure that I screwed up one of the data setup entries, like scope height. I've used a Labradar and oehler chronographs to record muzzle velocities, both of which provide results very close to each other. My real life ballistic chart is spot on in a hunting situation.

Until you shoot at 8500 feet. I actually zero at 500 yards at the Phoenix Rod and Gun Club but only when conditions are dead calm. I enter my ballistic data into my SIG with a 200 yard zero. Once I am zeroed at 500, I range the 500 yard target and note the MOA dial up. I adjust my elevation turret to match that MOA, then dial down to zero for my 200 yard zero. Works great.

 

[ARlife4me]

Depends! Are you wanting pbr or wanting the 4" kill box range w/o adjusting optic? Like yote hunting within 300 yards. 100 is the easy button depending on optic, then confirming out to 500 if shooting further. My old 264wm w/ duplex was sighted at 100, but shot flat enough to not move adjust out to 600. All I did was use over ir under the hair depending on distance.

I have quick target and will test against it. I have 1 of those cameras that have 1 mile range, so I might set something out at 1k and test.

 

[memtb]

I used to use a 300 yard zero and do what you said. But with a 200 yard zero you don't have to worry about holding low. This year I shot a deer at 410 (dialed up) and one at 175 (just held dead on). The problem with a 300 yard zero is your bullets are 4" high at 170 - game at that distance is often aware something isn't right and you often have to shoot fast. That deer I shot at 175 was walking right to left, so I had to pay attention to that - I don't need to think about holding low and giving it a slight lead with a 200 yard zero.

If you use the same rifle/load for everything, 365days/year…..it's reflex!

Even "if" you screw-up…..4" on a big game animal is inconsequential! Unless it is a minimal cartridge pushing a fragile bullet…..neither of which my wife and I can be accused of! Again, this method works for us….. the mileage of other's may be different! memtb

 

[Taylorbok]

How does one measure "scope height"? No matter what I try I feel like it is only an approximation.

Scope height ideally should be measured at the Objective lens but it's not going to make a big difference.

There's several ways to skin a cat. If you wanna get anal measure overall and subtract 1/2 obj. dia. and 1/2 barrel diameter.

Personally I make a mid point mark on my scope and barrel and measure with calipers.

For all intents and purpose you can just eyeball center of scope to center of action and call it good. If you are with in 1/10 of an inch you'll be fine.

 

[skipglo]

300 yards for dedicated hunting rifles like @ memtb....just far less words...

 

[Clem Bronkoski]

Well after reading all the posts and doing some more research I've decided on zeroing at 100 yds. This is solely a target rifle with occasional hunting use from a fixed position for long range shots with time to adjust my turret.
Thanks for your input and suggestions.

 

[LRNut]

If you use the same rifle/load for everything, 365days/year…..it's reflex!

Even "if" you screw-up…..4" on a big game animal is inconsequential! Unless it is a minimal cartridge pushing a fragile bullet…..neither of which my wife and I can be accused of! Again, this method works for us….. the mileage of other's may be different! memt

At 170 or so you are often shooting in a less than rock steady position - suppose you shoot 3" groups at 170 from a less than ideal position. Half of your shots at any range are going to be above your point of aim; doesn't matter how far you are shooting, that is a fact. So if we move that 3" group four inches high, we have some shots as high as 6.5". If you can only shoot a 6" group at that range (say, standing or even standing off sticks), you now have your highest bullets hitting 10" high. With a 200 yard zero, 100% of your bullets will land in that 10" vital area.

 

[bamban]

For short range application hog gun with M80a1 projectile, I zero at 50. Just shoot in.

Banish 30 Gold suppressed AR10, 20 inch KBI.

 

[HRM Johnny]

I tried with two different ballistic apps. I fiddled with input data until I came up with a result that was close to my real world results. Adjusting the MV and the scope height brought trajectory results pretty close to what I got at the range on paper.

This has been a very interesting read. Thank you for starting it.

 

[HRM Johnny]

And get a good ballistic app like Eagle ballistics

Thank you

 

[Clem Bronkoski]

Man that 300 yd zero does have its advantages for hunting. I wouldn't even have to mess with the elevation with my probable load. I can hold dead on out to 350 yards. Anything beyond that I just dial in the elevation. Sometimes the animal may just be still for a couple seconds and messing with the turret could mean the difference between tag soup and a full freezer.

 

[Clem Bronkoski]

100 yards
And get a good ballistic app like Eagle ballistics

Too bad they don't make it compatible with android systems.