Calibers for rifle sight zeros at 150 yds, oh no…

Ontario Hunter said:

My 404 was zeroed maybe an inch high at 100 meters and in Africa it was still bang on at 196 meters shooting my eland. But he was downhill (not significantly). I'm guessing my 400 gr Barnes loads are flying at ~2200 fps muzzle velocity. I wonder what velocity was used for this chart.

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None of my business, and not interested in getting into an argument, but what you are saying is mathematically impossible.

With a .404 Jeff 400 gr at 2,200 fps, if you are 1" high at 100 meters, you are 7" low at 200 meters, if shooting with a scope typically 1 3/4" above the bore.

If shooting with iron sights that are lower to the bore, the drop at 200 meters increases to 8".

196 meters, and "not significant" downhill shooting (or uphill for that matter) will not significantly change these numbers.

If your shot happened to land "bang on" at 196 meters, it simply means your rifle was wiggling on the sticks, or you yanked the trigger, but the hunting Gods took pity on you and the barrel was randomly just in the right spot when the bullet left the tube



The chart shown by Jefferry404 is pretty much right on the money...

The above table also illustrates something that the Taylor chart does not show, but that is very important for DG: for real-life hunting use, especially with iron sights, a 100 yards/meters zero is virtually indistinguishable from a 50 yards/meters zero.

one can argue that once the first sight is filed in, the leafs must follow it exactly with the offset for the longer ranges. The issue is probably due more to eyesight and trying to resolve the 10-20 mils of V above the fixed sight. For example, on the Gibbs, will machine the express sights as follows:

75yd sight offset 19 mils
150yd sight offset 30 mils
200yd sight offset 38 mils

Here is what 11/1000 looks like for the 150yd leaf V above the fixed sight V

@One Day... yep bang on.
There usually 2 zeros, an earlier one that rises up before the actual zero falls. So, the guys asking for a 50yard zero really are short changing themselves.
For my load design, particularly for express sights, I take into account my shooting ability at 100yds, i.e. group size, and this dispersion widens the trajectory window about the targeted game vital zone.
Here is an example of my 404 Jeffery 400 grain DGX load.
125yd zero rises to 1.1" at 22yds and has a PBR of 190 yards for Zebra.

Jefferry404 said:

@One Day... yep bang on.
There usually 2 zeros, an earlier one that rises up before the actual zero falls. So, the guys asking for a 50yard zero really are short changing themselves.
For my load design, particularly for express sights, I take into account my shooting ability at 100yds, i.e. group size, and this dispersion widens the trajectory window about the targeted game vital zone.
Here is an example of my 404 Jeffery 400 grain DGX load.
125yd zero rises to 1.1" at 22yds and has a PBR of 190 yards for Zebra.

View attachment 805928

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Id want fixed 100 then either 200 and a 300

that was for O'Hunters benefit
Actually, there can be a bit of science for the express sight zeros depending upon your personal accuracy and expect game animal.
My iron sight accuracy at 100yds is ~2" and if brown bear is on the menu,
my 404 Jeffery express sight zeros are 75,150,200 yds. The reason for those choices
are that the PRBR for the 75yd zero ends at 155yds and the 150yd zero PBR ends at 195yd.
So i just need to est. if distance is somewhat below 150yds, then the 75 gets me there. But if it looks like a bit more, then flip up the 150yds and this get me to 195. If the animal is really out there, then flip to the 200yd sight and gets out to 230yds.

One Day... said:

None of my business, and not interested in getting into an argument, but what you are saying is mathematically impossible.

With a .404 Jeff 400 gr at 2,200 fps, if you are 1" high at 100 meters, you are 7" low at 200 meters, if shooting with a scope typically 1 3/4" above the bore.

If shooting with iron sights that are lower to the bore, the drop at 200 meters increases to 8".

196 meters, and "not significant" downhill shooting (or uphill for that matter) will not significantly change these numbers.

If your shot happened to land "bang on" at 196 meters, it simply means your rifle was wiggling on the sticks, or you yanked the trigger, but the hunting Gods took pity on you and the barrel was randomly just in the right spot when the bullet left the tube

View attachment 805908

The chart shown by Jefferry404 is pretty much right on the money...

The above table also illustrates something that the Taylor chart does not show, but that is very important for DG: for real-life hunting use, especially with iron sights, a 100 yards/meters zero is virtually indistinguishable from a 50 yards/meters zero.

Click to expand...

Hit it three times all in the boiler room. PH ranged it at 196 for first shot (exit is in shoulder). He didn't go far before stopping. We moved maybe twenty yards closer for following shots. It is what it is ... or was.

@Josh P
actually, you can find scopes with ballistic reticles that will work.
going thru this for a couple of rifles and found a few scopes.
The Trijicon Huron 1-6x24 Riflescope BDC for my 416 Taylor

gives the folloiwn zeros:
rel2zro huron zro
0.00 moa 75 yds
2.28 moa 170 yds
5.03 moa 240 yds
8.27 moa 310 yds

rounding these to say 175, 250, and 300yd for field use, changes the impact less than ~1.5".

Jefferry404 said:

@Josh P
actually, you can find scopes with ballistic reticles that will work.
going thru this for a couple of rifles and found a few scopes.
The Trijicon Huron 1-6x24 Riflescope BDC for my 416 Taylor
View attachment 805956
gives the folloiwn zeros:
rel2zro huron zro
0.00 moa 75 yds
2.28 moa 170 yds
5.03 moa 240 yds
8.27 moa 310 yds

rounding these to say 175, 250, and 300yd for field use, changes the impact less than ~1.5".

Click to expand...

Careful the anti mil reticle folks will join in lol

Interesting conversation. I had developed the following table for my .450/400 set of barrels and came up with a 75 yard zero as the best solution where I did not need to worry about calculations in close ranges and out to 125 yards. Most important I wanted to make sure I was under half an inch at 50 and under an inch at 100.

Jefferry404 said:

@One Day... yep bang on.
There usually 2 zeros, an earlier one that rises up before the actual zero falls. So, the guys asking for a 50yard zero really are short changing themselves.
For my load design, particularly for express sights, I take into account my shooting ability at 100yds, i.e. group size, and this dispersion widens the trajectory window about the targeted game vital zone.
Here is an example of my 404 Jeffery 400 grain DGX load.
125yd zero rises to 1.1" at 22yds and has a PBR of 190 yards for Zebra.

View attachment 805928

Click to expand...

Flawless logic

I use the same logic for my .458 Lott with Leica Magnus 1-6x24 shooting 500 gr TSX @ 2,200 fps.



I zero it for a true zero at 100 yards, which is where it stands during a DG hunt. It also happens to be an exact zero at 50 yards, and certainly "minute" of Elephant brain or Buffalo heart from 25 to 125 yards.




But if we need an Impala for the pot or for bait, or if we bump into the next World Record 3-Toed Unicorn, 8 clicks up on the scope give me a Maximum Point Blank Range (MPBR) of 225 yards for a 6" vital area, which accommodates anything from Impala to Eland (hmmm...).



The argument can certainly be made that a +3" / -3" 225 yards MPBR also works just fine for Buffalo, but for Elephant I want the bullet to land exactly where I point it, so I prefer the exact 100 yards zero.

Jefferry404 said:

my Gibbs barrel. fixed sight zero at 75yd, 1st leaf at 150yd and 2nd leaf at 200yds
View attachment 805903

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I'm wondering what you plan to hunt at 150 or 200 yards open sights with this big pipe?
It seems you are planning on a muzzle brake.

No, never brake. Only plan something big at less than the fixed sight zero…
But my reading of Neumann, Sutherland, Bell, Taylor got me to realize that in those days, strike opportunities as life was hard.
Those times are gone but as a nod to them, maybe they could do a Gibbs at 200 yards on a Zebra. Can I now, no, but there is always hope.

I zero at 100 yds, but my point of impact is based on the maximum point blank range of the ammo/rifle combo I'll be using.

Ah…
One of my engineers told me once “ beat a dead horse, bury it, dig it up and beat it again” so I never learn
The zebra just represents a “vital zone” target for the PBR, better than just saying a 13” diameter circle
So my challenge is can I put a 525gn into a 13” circle at 200yds? The cartridge can and the rifle can but me…

Here is my first brace of rifles, 505 Gibbs top, 416 Rigby bottom, scope less. Gibbs 1 fixed at 75yds. practical.

But I wanted another Gibbs…

Thanks,
Roy Bedeaux out of Albuquerque. His integral barrels and what he thought the rifles should be.
He has since retired, building black powder and single shots for himself but in Sept. I took him the “stuff” for 6 more builds (375,404,3006,338,9.3x62 and 416). I give him the stuff, some of my thoughts and he builds something

Grumpy gumpy said:

One of those hits appears to be in the front 'elbow' another in the bottom of the lungs or upper intestine area, can’t see the third, so maybe that was the fatal one. An autopsy would show
Gumpy

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Mr Gumpy, I think it depends very much on the angle of the shot before we dismiss it outright. The particular shot you refer to as merely hitting the elbow could have an entirely different outcome if the bullet strikes diagonally or at an angle of 30–45 degrees. Depending on the trajectory, it could potentially damage major blood vessels returning deoxygenated blood to the heart, or even penetrate and rupture the lungs. Either scenario could prove fatal.

The point is that shot placement cannot always be assessed in isolation from the angle of entry and the underlying anatomy. What might appear to be a relatively insignificant wound from one perspective could be a very different proposition from another.

Jefferry404 said:

...
So my challenge is can I put a 525gn into a 13” circle at 200yds? The cartridge can and the rifle can but me…
...

Click to expand...

Yes you can... and whether it be a .275, or a .375, or a .505 matters little

The answer to that is practice. And contrary to what many think, for lack of actual experience, it does not necessarily imply always practicing with full loads. Certainly, you can load training rounds for your .505 and it will help, but in truth, shooting form is better developed with a man-size bolt action .22 LR (e.g. Win 52, CZ 457, Walther KKJ, Anschutz 1761 or 1710 series, etc.) which will let you see your mistakes and flinches by not hiding them in blast and recoil.

Actually, budget allowing, tasking Roy Bedeaux to build you a .22 LR trainer on the template of your DG rifles could be really awesome. It has been done before, and is still being done. Few folks in their right minds believe that Blaser is selling a $2,000 .22 LR conversion for a $,5000 rifle (base price) for kids to plink tin cans with

The reason I now shoot my .458 Lott ~1.5+ MOA standing from the sticks (see above group) is because I shoot ~5,000 rounds of .22 LR per year off the quad sticks (I am blessed to live in AZ on a couple dozen acres and I have my own 100 yards shooting lane). But even a 25 yards urban indoor firing range will do just fine, just reduce the size of the target as you reduce the distance.

Additionally, in my case, the transfer of shooting form from .22 LR to .458 Lott (or .375, or .300, or .257, etc.) is facilitated by the fact that Blaser makes a .22 LR barrel for the R8, so I train with the exact rifle I hunt with. But this also works with different rifles.

Good shooting technique (proper shooting form i.e. handling of the rifle; rifle control; breathing control; trigger control; position on sticks; etc.) is the same whether the rifle on the sticks is a .22 or a .505. And when you learn to roll with the recoil rather than fight it -- the part that SStomcat still needs to learn, and no this is not an attack on him -- then standing behind a .22. a .375 or a .505 on the sticks does not really matter to how accurately you deliver your shot. BEWARE, as you probably know, this does not apply to the bench where big calibers will hammer you!

The issue, for most folks, is that it is impractical, physically (you would need to re-barrel every year!) and financially, to shoot several thousand rounds of DG caliber per year, so they show up in Africa having fired a few boxes in the last few months. It is not enough. You do not learn to ride a bike without thinking by going around the block just once. Burn .22 LR by the thousands until you hit a 2 inch "plate" (NOT a 12 or 8 incher or even a 6 incher) at 100 yard standing off the sticks without thinking, then 13" at 200 will become natural.


4, 3, and 2 inch "plates" at 100 yards

As to iron sights vs. scope, it is all a question of visual acuity. After cataract surgery on both eyes, and coming fast on the big 7oh, my iron sights days are over, but good DG glass keeps me in play

As a side note from someone with no big bore experience, these cartridges really do not drop as drastically is I thought they might. No doubt there is a significant arc to the flight path but I honestly thought it would be worse considering some of these bullets have the BC of a bowling ball.

SStomcat said:

Mr Gumpy, I think it depends very much on the angle of the shot before we dismiss it outright. The particular shot you refer to as merely hitting the elbow could have an entirely different outcome if the bullet strikes diagonally or at an angle of 30–45 degrees. Depending on the trajectory, it could potentially damage major blood vessels returning deoxygenated blood to the heart, or even penetrate and rupture the lungs. Either scenario could prove fatal.

The point is that shot placement cannot always be assessed in isolation from the angle of entry and the underlying anatomy. What might appear to be a relatively insignificant wound from one perspective could be a very different proposition from another.

Click to expand...

He said he was shooting downward, hence my comment about autopsy, either way the animal was down and as long as it didn’t suffer prolonged trauma it is a moot point
Gumpy

@One Day...
Same gunsmith thought I should have a full size, full blown practice rifle…22LR, holds 5 down

Only issue I have is the short bolt throw compare to the GMA African