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25yd sight in?

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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: November/22/2014 at 17:04
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at what distance do u guys shoot your rifles to sight in?   i read some article on facebook and guys were commenting saying 25yds       
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: November/22/2014 at 18:48
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My AR or bolt guns for hunting? AR is zero'd at 50 yards, my center fire bolt guns at 100 yards, my rimfires are 25 or so.   
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: November/22/2014 at 19:24
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bolt guns for hunting. having trouble with human error using my sangbags. figured it might be easier to sight in closer than the usual 100yds. but i think ima just gonna buy a nice rest
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/05/2014 at 16:42
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I make sure I'm on paper at 25yds,bring it in at 50 yrds & zero at 100 & 200 yrds depending the caliber!
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/05/2014 at 16:54
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That really depends on the gun, the caliber and the application.

With the guns I shoot, here is the list by caliber:

338LM: 300 yards
6.5x47, 7.52x51, 5.56x45, 6.5Grendel, 280Rem,  7.62x54R, 8x57, 7.5x55: 200 yards
458SOCOM, 300Blackout, 7,62x39: 100yards
22LR: 50 yards

ILya
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/06/2014 at 17:07
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I try to sight in scoped rifles at 200 yds. Iron sight rifles at 100 yds. 22 with a scope at 50 yds and 22 with iron sights at 25.   I prefer to practice at the actual distances I am likely to shoot.   Oddly enough the military sights in at 25 meters.   I don't mind starting at 25 yds when I put a new scope on just to get on the paper then move to 100 then to 200 yds.  I generally try to stage my hunting shots for 200 yds.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/06/2014 at 18:13
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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/09/2014 at 10:35
Alan Robertson View Drop Down
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As others have said, sighting at 25 yds gets you on paper and interestingly, a 25 yd sight- in will often get you very close to a centerfire rifle's optimum hunting trajectory, or Point Blank Range for that caliber, which in consideration of the rifle's power, may be a shorter distance than the rifle's maximum point blank range. (MPBR), which is a very useful concept for a hunting rifle.
MPBR... that's the distance above or below the line of sight which the bullet will move during it's time of flight. For deer sized game and larger, that's usually given as +/- 5"... and the MPBR is the distance that your rifle will shoot without the trajectory of the bullet going above or below 5 inches from your line of sight.

Example 1: A standard .30-06 factory 150Gr load @2920 fps will provide a MPBR of ~335 yds... the rifle is actually sighted in @286 yds, is .3" high @25 yds and a full 4" high at 100yds. The trajectory of the bullet will be no more than +/- 5" high or low from zero to 335 yards... visualize a 10" pie plate covering a deer's vitals and aim for the center... that will put a shot in the deer's vitals out to 335 yds.
What if you want your rifle to fire along a trajectory which deviates no more than say, 2" above/below the line of sight, i.e. a flatter trajectory, Point Blank Range? Using the same .30-06 factory load:
Example 2: .30-06 150 Gr SP, 2920 fps: 200yd zero gives +/- 1.8" to 230 yds, .3"low@ 25yds and 1.8"high @100 yds. The new 2"PBR is good to 235yds, while still maintaining a 5"max drop MPBR out to 275 yds.
Example 3: Same load as above with 25 yd. zero: 2.8"high @ 100yds (max height 3.3"@162 yds,) 4.7"low @300 yds. Not bad.

It's easy to see that you can tailor your rifle's Zero to match your purpose.

A friend swears by sighting in all of his centerfire rifles at 3" high@100yds. While his method may not produce optimum MPBR or the flattest trajectory for all purposes with all rifles, it just works well for just about any centerfire hunting rifle, as does a 25 yd zero.

Sighting in at longer ranges allows you to really fine tune your rifle's sight- in, as the greater distance allows you to correct small errors in windage and elevation which might not be apparent at 25 yds.
Target and tactical shooters aren't so concerned with MPBR and dial- in elevation adjustments to match the target range.

AR15 iron sights are 2.6" above bore axis and trajectory to line of sight relationship changes because of the high sights. As example, I have a scoped AR with sight height 2.94".. I have a load which is sighted in 1"low @25yds, which gives me a 300 yd zero and 5" MPBR of 350 yds. Wouldn't think of shooting at game at that distance with an AR, but it's good to go for zombie attacks.

Iron sight .22 rifles sighted in at 25 yds are also zeroed @ 50 yds, with about 6" drop @ 100 yds.

Here's a great link for figuring out different trajectories with your rifle and ammo and tailoring your sight- in zero for your purpose:
http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi


Edited by Alan Robertson - December/09/2014 at 11:18
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/09/2014 at 12:30
Alan Robertson View Drop Down
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Here are some common deer hunting calibers using popular factory ammo specs and compared with 25 yard sight- in, and 3"HI @ 100 yds :
PBR= Point Blank Range, MPBR= MaxPBR = +/- 5"

.30-30 Win, 150 Gr FP, 2390fps: 25 yd zero, 1.9" Hi @100 yds (also max rise), also zeroed ~160 yd, 5"Lo~220yds.
.30-30 Win, 150 Gr FP, 2390fps: .3"Hi @ 25, 3" Hi @ 100, 3"Lo@225 yds, 5" Lo @ 240 yds. (Zero also @192 yds)
MPBR Zero= 235 yds. MPBR= 269 yds,
note: sight in 3"Hi @ 100 yds seems about ideal for a 150 Gr .30-30, imho

.270 Win, 130 Gr SP, 3060 FPS: 25 yd Zero, 3"Hi@100, max Hi 3.6"@170, 5"Lo@335,
MPBR 360Yd w/306 yd Zero

.243 Win, 100 Gr SP, 2960 FPS: 25 zero, 2.9" Hi@ 100 yds, max Hi 3.4@ 145, 5" Lo@ 315 yds
MPBR 344 yds w/294 yd zero

.25-06 Rem 120 Gr SP, 2990 FPS: 25 yd Zero, 2.9 Hi@ 100 yd,max Hi 3.4@145, 5" Lo@ 310 yds
MPBR 341 yds w/291 yd zero

.308 Win 150 Gr SP, 2820 FPS: 25 yd .1" Hi (24 yd zero), 3" Hi @100, max Hi 3.3" @145, 5" LO @ 300 yds
MPBR 332 yds w/282 yd zero
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/09/2014 at 12:55
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.223 for coyotes, pigs, and deer, .338 Federal, 6.5x55, 6mm rem, 7mm mauser, .50 muzzleloader, all sighted dead on the dot at 100 yards. all are good to make kills to 250 yards. 
If i ever go antelope hunting i will use the 6.5x55 and will click 4 or 6 times up, to get more range. 
I  would sight in and practice for the game hunted. Deer are shot at 100 yards or less, elk maybe at 200,  
etc.
out west you may need to shoot to 200-300, yards, that;s what i would sight in for. Really, shoot to 200 yards, if the scope is only slightly canted sideways you will be way off target. 

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/09/2014 at 13:03
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Good info there, Alan.  I use 25 and 50 yard zeros a lot, but I ALWAYS check the "long range zero" as well.  Not that I don't trust the ballistics calculations… "trust, but verify".
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/09/2014 at 13:16
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what Kickboxer said. I went with a buddy to CO antelope hunting, I did not have a tag, he did. Before the hunt he practiced his .308 all the way to 400 yards. We noticed that between 100 and 400 his shots were drifting and dropping more than normal, it was not the wind. We re-mounted the scope, he shot the same load until he could hit steel plates at 400. On the ranch he fired a few more, to check again. On the ranch there were a few people who had missed their shots several times. They all had their apps on phones and all sorts of long range rigs and turrets on scopes. My friend just had a .308 and a simple Nikon scope. He made a one shot kill at 440 yards.  off seated bi pod. 
Don't trust the ballistics table on the ammo box. First off, if it's that far hunt a little more and get closer, it's fun, believe me. Second, shoot the rifle at the range that you expect to have the animals to be. 
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/10/2014 at 06:09
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Thanks Alan!  This was quite interesting, I never played with changing zero.  Never really gave it much thought.  The examples were great at illustrating different zero MPBR... Another concept I hadn't really given much thought!
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/10/2014 at 09:09
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Yes, thanks Alan! I never thought of that concept either.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/12/2014 at 03:23
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When considering why it's even possible to zero a rifle at ~25 yards it's useful to picture what happens with ballistic trajectories. Unless your zero is really zero (yards), you're aiming the rifle barrel up (if ever so slightly) to compensate for the bullet drop. The bullet is going to travel an arc-like path that starts out below your zero at whatever your scope height is, crosses the zero line at some point before the zero, drops down through the zero and continues dropping until it either hits something or succumbs to gravity. The farther out your zero, the closer to where you are is where the bullet will first cross the zero line. As mentioned, 25 yards works pretty well for a lot of calibers/loads because it happens to coincide well with battlefield (or max. PBR) zeros.

(Geek Note: You could actually zero at the apogee of the trajectory, in which case there would be no other point where the bullet's flight path crossed the zero line. For example, I see with my regular 100-yard zero that the bullet crosses the zero line at 70 yards. So if I zeroed at ~85 yards I'd have a zero that would make someone, somewhere pee his polyester pants).

If I want to zero at max. PBR, which JBM tells me is a 291 yard zero, my drop at 25 is .2" or .2 MILS (if you prefer angular units) meaning a bit higher than zero. Okay, this is making sense because .2 is pretty close to 0 so that must be about where the bullet crosses the zero line. But since JBM allows us to use 1 yard increments, let's fine tune that. Now I see that 23 yards is where I get a drop of 0, matching my drop out at 291 yards.

So what happens if I go back into JBM and put 23 as my zero? Now I see that my drop at 23 is 0 and at 291 it's 0, meaning I could input my zero at either 23 or 291 and my rifle would be zeroed for max. PBR. I see too that if I zero for max. PBR I'm going to be 1.1 mils (or 3.8") high at 100, which jibes with the typical advice to sight in 3-4" high at 100.

What if I don't have a 23 yard distance but still wanted to zero for max. PBR? What if I shoot at a range that is at 25 yards or 50 yards? If I trust the inputs I've made into my ballistics calculator (and its JBM or the equivalent) I see I can stick with my zero of either 23 or 291 (the easy way to do this in JBM is to just check "Zero at Max. Point Blank Range"). I can see that at 25 yards my drop is .2" or .2 MILs. That means I could dial .2 mils low (or hold) and zero at 25 yards.

What if I want to zero at some range other than max. PBR but don't have access to that distance? Let's say 200 yards but I only have access to a 50 yard range. If I go into JBM and enter a 200 yard zero I can see that at 50 yards I'm going to be 1.9" high or 1 MIL high. I'd put my scope on target and adjust elevation until the POI (point of impact) is 1.9"or 1 MIL higher than my POA (point of aim). In other words, you can pick any zero you want and adjust your rifle at any range you want using the values for that distance. 

In the end though you're always better off verifying at the longest distances you can. While there are BCs and bullet data I trust (Berger comes to mind) I've found out the hard way that bullet manufacturers either don't measure BCs accurately or are prone to fudge numbers. Personally, I prefer to boresight my rifle scopes and zero at 100. With a good scope like any of the SS line, I've always gotten on paper that way. As soon as I can (meaning somewhere around 10 verification shots once the scope is dialed in) I move to the 300 or 400 yard ranges. I feel much more confident with my hunting rifle when I hear a 4" gong getting smacked at 400.



Edited by jonoMT - December/12/2014 at 04:10
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/12/2014 at 05:44
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My head is spinning but i follow.  Thats a great trick and you explained very clearly, thanks! Excellent
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/12/2014 at 08:30
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Just picked up a Elcan M145 for a steal.   Given the reticle and the instructions it actually recommends to start your zeroing process at 10M.  Then confirm further out.  I've never delt with Elcan but I'm putting this on a M4 clone so I'll check it on steel plates after getting a chance to do all this.  I like the concept of the MBPR and zero for a battle  rifle or hunting rig.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/12/2014 at 09:44
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One thing I meant to mention is that MPBR is affected by how small a vertical range you want. In other words, if you want to keep the bullet within an 8" range, say for antelope, vs. a 10" range for deer that will decrease MPBR. Using the more detailed JBM calculator at http://www.jbmballistics.com/cgi-bin/jbmtraj_drift-5.1.cgi you can adjust this by changing the Vital Zone Radius. 4" would fit my example of MPBR for smaller game animals. In my case, the zero would go from 291 to 267 and MPBR would drop from 345 yards to 315 yards.

My advice is to even look at basing it on something you're comfortable with, say 300 yards. That way, mentally, you have it in your head that anything bigger than twice the specified radius between you and 300 yards is going to get hit. For my load, that's a 3.5" radius and zero at 250 yards (or if I want to get on paper 26 yards). 7" across that whole distance is "flat" enough for any antelope, deer or elk I'd picture shooting with a .308. (I'd probably use this method if I wasn't in love with my SS 3-15! I've got come-ups memorized in 25 yard increments out to 500).
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/13/2014 at 08:51
Alan Robertson View Drop Down
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Great info, jonoMT,
Many thanks.
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