.45-70 Government zeroing
What does a 100 yard zero do to a .45-70 Government?
Quick answer
A .45-70 Government zeroed at 100 yards, using 405 grain lead at a catalogue 1,330 feet per second and a 1.5 inch sight height, sits 0 inches above the line of sight at 100 yards and 79.6 inches below it at 300. The bullet never rises more than 2.1 inches above your line of sight.
Choosing a zero distance is choosing where you want your error to be. Every zero is a compromise between shooting high in the middle distances and shooting low at the far end, and there is no zero that avoids both.
The figures below assume 405 grain lead at a catalogue 1,330 feet per second and a sight height of 1.5 inches from the centre of the bore to the centre of the scope. Both of those are assumptions, and both matter. Use the muzzle velocity printed on your own box, and measure your own sight height, because a rifle that differs by 100 feet per second or by half an inch of sight height will not match this table at distance.
Drops like a thrown rock past 150 yards. A scout scope or a low power optic with a generous eye box is worth more here than magnification.
On this page
Drop table for a .45-70 Government with a 100 yard zero
What produced these numbers
G1 point mass model, BC 0.281, muzzle velocity 1,330 fps, sight height 1.5 in, zero 100 yd, 10 mph full value crosswind
A positive figure is above your line of sight and a negative one is below it. The MOA and mil columns are the come-up you would dial, so a negative drop needs a positive come-up.
Read the drop column in inches for a hold, or the MOA and mil columns for a dial. Wind is a full value crosswind at 10 miles per hour, which you can scale in your head: a 5 mph wind is half, a 20 mph wind is double.
With a 100 yard zero this load is -24.1 inches from the line of sight at 200 yards and -79.5 inches at 300, needing 25.32 MOA of come-up to centre at 300.
Sourced figure
| Distance | Path | Come up (MOA) | Come up (mil) | Velocity | Energy | Wind at 10 mph |
|---|---|---|---|---|---|---|
| 25 yd | 0.9 in | 3.6 MOA | 1.05 mil | 1,284 fps | 1,483 ft-lb | 0.2 in |
| 50 yd | 2.1 in | 3.95 MOA | 1.15 mil | 1,242 fps | 1,388 ft-lb | 0.7 in |
| 100 yd | -0 in | -0 MOA | -0 mil | 1,165 fps | 1,221 ft-lb | 2.8 in |
| 150 yd | -8.5 in | -5.39 MOA | -1.57 mil | 1,102 fps | 1,092 ft-lb | 6.3 in |
| 200 yd | -24.1 in | -11.49 MOA | -3.34 mil | 1,051 fps | 994 ft-lb | 11 in |
| 250 yd | -47.5 in | -18.16 MOA | -5.28 mil | 1,009 fps | 916 ft-lb | 16.8 in |
| 300 yd | -79.5 in | -25.32 MOA | -7.37 mil | 973 fps | 852 ft-lb | 23.6 in |
| 400 yd | -171.7 in | -41 MOA | -11.93 mil | 913 fps | 750 ft-lb | 40 in |
| 500 yd | -305.6 in | -58.37 MOA | -16.98 mil | 863 fps | 670 ft-lb | 59.8 in |
| 600 yd | -486.2 in | -77.39 MOA | -22.51 mil | 820 fps | 605 ft-lb | 83 in |
Computed with a G1 point mass model from the published ballistic coefficient. It is not radar data and it does not model spin drift or Coriolis. Confirm it on paper at a measured distance before you trust it past 400 yards.
How a 100 yard zero compares with the alternatives
The same cartridge and the same rifle, at every zero distance worth using. The middle column is how high the bullet ever rides above your line of sight, which is the figure that decides whether you can hold dead centre.
A 100 yard zero keeps this load within 2.1 inches above the line of sight, against 31.3 inches for a 300 yard zero.
Sourced figure
| Zero | Highest above line of sight | Path at 200 yd | Path at 300 yd | |
|---|---|---|---|---|
| 25 yd zero | 0.2 in | -31.6 in | -90.9 in | |
| 50 yd zero | 0 in | -32.3 in | -92 in | |
| 100 yd zero | 2.1 in | -24.1 in | -79.5 in | This page |
| 200 yd zero | 12 in | -0 in | -43.4 in | |
| 300 yd zero | 31.3 in | 29 in | -0 in |
A higher mid range trajectory buys you a flatter looking far end and costs you accuracy on a close shot taken with a centre hold.
What is the maximum point blank range for this load?
Point blank range is the distance over which you can hold dead centre and still land inside a target of a chosen size, with no holdover and no dialling at all. It is the most useful concept in hunting ballistics and the most commonly misused.
For this load, with an eight inch vital zone, the best zero is 125 yards, which gives a maximum point blank range of 145 yards. The bullet never rises more than 3.9 inches above the line of sight and has not yet fallen four inches below it at 145 yards.
That is different from the 100 yard zero on this page. A 100 yard zero is easier to confirm on a range that has a 100 yard line, and it is the right choice if you would rather verify your zero properly than squeeze the last few yards out of a centre hold.
The vital radius is your choice and nothing here decides it for you. Four inches is the usual figure for deer sized game and it is a convention, not a standard. Choose a smaller number and your point blank range shrinks, which is the correct trade if you are not confident of the shot.
Where this load stops being useful
This load stays above the speed of sound out to roughly 100 yards in standard conditions. Past the transonic region a bullet can become unstable and groups open up unpredictably, which is why published drop tables become much less reliable there.
Energy is the other limit and it is a matter of ethics rather than physics. At 300 yards this load carries roughly 852 foot pounds. What is enough is a judgement about the animal, the shot placement and the law where you hunt, and it is yours to make rather than ours.
Before any of this matters, the scope has to be mounted square and torqued properly. A reticle canted two degrees is invisible at 100 yards and throws the shot several inches sideways by the time you have dialled a come-up this large. Work through levelling the scope before you chase the last tenth of a mil.
Glass and gear for zeroing a .45-70 Government
Chosen against the numbers on this page rather than from a general list, so the recommendation cannot contradict the arithmetic above.
Vortex Crossfire II 3-9x40 Riflescope, Dead-Hold BDC Reticle
$128.99 Full specificationsThe default first centrefire scope, and the reason is the warranty rather than the glass: Vortex transfers its lifetime warranty to whoever owns the scope, with no receipt and no registration, which is worth more over twenty years than a modest optical upgrade.
Best for: a first deer rifle where the scope should outlast the rifle
Check price on Amazon
Vortex Diamondback 3-9x40 Riflescope, Dead-Hold BDC Reticle
$249.00 Full specificationsThe same configuration as the Crossfire II with better glass and a cleaner image at the top of the magnification range, which is exactly where a cheaper scope goes soft and dark.
Best for: the buy-once hunting scope at a sensible price
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Leupold VX-Freedom 3-9x40 CDS Duplex Riflescope
$299.99 Full specificationsThe CDS turret is the point: Leupold will cut you a custom elevation dial marked in yards for your load, so dialling a come-up stops being arithmetic and becomes reading a number off the turret.
Best for: a hunter who wants to dial rather than hold over
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Burris Fullfield E1 3-9x40 Riflescope
$169.99 Full specificationsA long-running American hunting scope with a forever warranty and a reticle with holdover marks that are actually usable rather than decorative.
Best for: a budget hunting build that still wants a real warranty
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Burris Fullfield 3-12x42 SC Riflescope
$259.36 Full specificationsTwelve power and a 42 mm objective is the sensible ceiling for a walking rifle: enough magnification to read a far shoulder, not so much that the exit pupil collapses at last light.
Best for: an all-round hunting scope with a little more reach than a 3-9x
Check price on AmazonHow we chose
We did not test these optics in person and we never claim to. Picks are researched from manufacturer specification sheets, published optical and ballistic formulas, and the recurring themes in verified owner reviews. Every pick is matched to a real objective diameter, a real tube size, a real ring height or a real exit pupil rather than to a price bracket, and it is placed in the tier where its capability actually belongs. Where a figure is shooter convention rather than a sourced number we label it, and where a manufacturer does not publish a figure we leave it out instead of estimating it.
Sources
- Published factory load specification: 405 grain lead at a catalogue 1,330 feet per second
- G1 standard drag function, the published Ingalls and Siacci reference
Frequently asked questions
Is a 100 yard zero good for a .45-70 Government?
A 100 yard zero is the easiest to confirm and the easiest to reason about, because the come-up you dial is measured from a distance almost every range has. For this load it leaves you 79.6 inches low at 300.
How high should a .45-70 Government be at 100 yards?
With a 100 yard zero, 0 inches high. The widely repeated advice to be two inches high at 100 yards is a rule of thumb rather than a specification, and it produces a different zero distance for every cartridge. Work from the zero distance you actually want instead, and let the figure at 100 yards be whatever it turns out to be.
Does sight height change my zero?
It changes the whole shape of the trajectory, not just the numbers. A higher scope means the bullet starts further below the line of sight and has to climb further to reach it, which steepens the near part of the path and moves the near zero out. This page assumes 1.5 inches. Measure your own from the centre of the bore to the centre of the scope tube, because it varies by more than an inch across ordinary rifles.
Why does my rifle not match this table?
Almost always muzzle velocity. Catalogue figures come from a test barrel that is usually longer than yours, and a difference of 100 feet per second is completely ordinary. Ballistic coefficient, altitude and temperature account for most of the rest. Chronograph your own load and use that number, and the far end of the table will tighten up considerably.
Should I dial or hold over?
Dial when you have time and a known distance, because it is more precise and it puts the reticle back in the middle of the glass where the optics are best. Hold when the shot is fast or the range is uncertain. Most hunters should set a zero that lets them hold dead centre inside their normal shooting distance and dial only beyond that.
How much elevation travel do I need for this?
Reaching 300 yards with this load needs 25.32 MOA of come-up from your zero. Half of a scope total travel sits above mechanical centre, and a rifle that is not perfectly aligned eats into that before you dial a click. Check the figure against your scope published travel, and add a canted base if the sum does not leave you a comfortable margin.
Researched, not professional advice. This page is compiled from published manufacturer specifications, published optical and ballistic formulas, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are shooter convention rather than sourced numbers, and they are labelled that way wherever they appear. Ballistic figures come from a point mass model using the ballistic coefficient the maker publishes, so treat them as a starting point and confirm them on paper at a measured distance. Confirm your firearm is unloaded with the action open before you mount, level, torque or bore sight anything. Verify a zero only on a supervised range or a safe, legal backstop, know what lies beyond your target, and follow the law where you hunt and shoot, including rules on land access and permitted cartridges.