Shooters Forum banner

zeroing in at 25 yards

147K views 44 replies 33 participants last post by  rojkoh 
#1 · (Edited by Moderator)
I have been told that when I sight my rifles (308 win and 30-06 sprfld.) in to dead on the bullseye at the 25-yard range that my rifles will be dead on at 100 yards. Is this a true statement? We were discussing how to sight in my rifles and not using so many rounds to do it. Then he said after the 100-yard sight-in is completed I could go up 6 to 8 clicks (1/4 @100 yards on the turrets) and be on target at 200 yards. What do y'all think about this..is he full of hogwash?
 
#34 ·
Once I arrive at my hunting destination, I always check my rifle and make sure it is on for the yardage I went to shoot Max at. down range. One time I went to Wyoming and stopped at the Jackson Hole shooting range to check my model 70 .338 mag & back up rifle, a .300 win mag model 70 Winchester.

I had my handloads worked out at home in Missouri Ozarks and both rifles shot lights out on targets. Matter of fact the .338 mag was shooting from the bench, an MOA of .575 and the .300 Win mag was also under an inch at .890. However, once I put 3 shots on the target at 100 yds with my .338 mag, the floor fell out from underneath me. Yes, this great shooting rifle moved a bunch or something happened in travel.

The best I could do was a solid 3.5 inches at 100 yards!:eek: I then shot at 200 yds and it was a nice big 7 to 8 inch spread between bullets. I also then shot the .300 mag and it was shooting around the 2 inch marker. So I did not have time to figure out what went wrong. I let 2 fellow club members shoot both rifles at 200 yds and again the results were not to my liking whatsoever.:(

I hustled my rearend to the truck and went to town, going to get some factory ammo and try those bullets instead. I found some .338 in 200 grain Barnes bullets (got 1 box) also picked up 2 boxes of Federal in 225 grain & 250 grain. I purchased 2 boxes of Winchester in the 180 grain for the .300 win mag. Then it was back to the rifle range. I shot the .338-mag and 3 rounds of the 225 and 3 shots with the 250 grain. I was pleased with the results. My .338 mag shot 1.3 inches for the 225 and the 250's even better at 1.1. The .300 Win mag shot 1.5 to 1.6 inches and that was good to go to camp.

I never found out what caused those rifles to be off so much but I can say with the help of the LORD, I got things taken care of quick and without incident. I took a nice 5 x 6 bull that year and sure wished I could have gotten a shot at the biggest bull I ever saw in the wild. I knew it would have went at least a 375 looking through my spotting scope for over an hour. He was so big, that when the heard final did get spooked by some hunters coming down the other side of the mountain bench, all this bull could manage was to trot off slowly behind the heard. Man he was in my dreams for several years afterwards. He had the biggest body I ever saw on a bull elk.:):D
 
#35 ·
Lots of advice on this one.

There are many ways to zero a rifle. Since NO 2 rifles will shoot EXACTLY the same, stating "you need to move turrets x amount up and y amount left" is guesswork, until it's verified at the range. (it may be close, right on, or way off) (IMO) it's better done at a range than a blackboard. STARTING at 25 yards (with a large unshot cardboard target) will Normally show all hits, thus saving ammo on shots you have no idea where they hit. If you are a decent shot, 1 shot may be enough for a ball park adjustment. Once zeroed at 25 yards you SHOULD BE on paper at 100 yards & fine tune from there, using 3-5 shot groups. The 1.5" high at 100 yards = dead on at 200 yard "rule" may be true for some guns/calibers, but certainly not all. You will still have to shoot them at that distance to verify it as fact, the same way you would need to verify a computer generated zero by actually firing the weapon at that particular range with that particular ammo. To answer your original question, "is HE full of hogwash?" Guilty of generalizing yes. FOS, not totally, nothing is written in stone when anticipating how a particular gun & load will shoot at any particular distance.
 
#37 ·
i have been told that when i sight my rifles (308 win and 30-06 sprfld.)in to dead on the bullseye at the 25 yard range that my rifles will be dead on at 100 yards ..is this a true statement.. we were discussing how to sight in my rifles and not using so many rounds to do it.. then he said after the 100 yard sight-in is completed ,,i could go up 6 to 8 clicks (1/4 @100 yards on the turrents)and be on target at 200 yard s..what do y'all think about this..is he full of hog-wash.
Depends on the ammo. All mine are zero'ed for 200 yards.
 
#38 ·
Wasting ammo

If you can't tell where your bullets are hitting, AT ANY RANGE, that IMO is ammo wasted. Hence using a real big unused piece of cardboard box to place your target on. How often do you see people trying to zero a new gun/scope at 100 yards & use up all their ammo without hitting paper & having no idea where their shots are going, yet they keep on shooting. :confused:
 
#43 ·
If you can't tell where your bullets are hitting, AT ANY RANGE, that IMO is ammo wasted. Hence using a real big unused piece of cardboard box to place your target on. How often do you see people trying to zero a new gun/scope at 100 yards & use up all their ammo without hitting paper & having no idea where their shots are going, yet they keep on shooting. :confused:
You should have been there when I managed to get an M14 1 inch Griffin and Howe mount for my Devine. Since it's 2" high and offset 1", it was a royal PITA to get zero'ed. The fun part was making sure it was properly set up for distance. Yes, in this case I had to start at 50, more to 100, 200, 300 and so on.

Fine with a non-critical scope, but step up to a serious scope, never could get it zero'ed and I put the Leupold 2X7 back on it.
 
#40 · (Edited)
Of course he is

i have been told that when i sight my rifles (308 win and 30-06 sprfld.)in to dead on the bullseye at the 25 yard range that my rifles will be dead on at 100 yards ..is this a true statement.. we were discussing how to sight in my rifles and not using so many rounds to do it.. then he said after the 100 yard sight-in is completed ,,i could go up 6 to 8 clicks (1/4 @100 yards on the turrents)and be on target at 200 yard s..what do y'all think about this..is he full of hog-wash.
Kentucky HR, say you are shooting 168gr Nosler Partition bullets from both the .308W and the 30-06 at the average best accuracy velocities (my own data) for the bullet to climb from below and cross your sight line at 25 yards with a scope line above bore of 1.5":

1. The .308W will be 2.8 inches high at 100 yards - on the crosshairs at 250 yards and 3.5" low at 300 yards.

2. The .30-06 will be 2.9" inches high at 100 yards - on the crosshairs at 260 yards and 2.7" low at 300 yards.

What this also means is that if you sight the .308W to also be 2.9" high at 100 yards, it will be dead on also at 260 yards and 3" low at 300. In the field there is exactly no difference between the two calibres - neither in trajectory nor in terminal performance on game. Both are deadly on any big game if the proper weight and strong construction bullets are used

Should you adjust as suggested by your uninformed friend you will be way too high at 100 yards...
 
#41 ·
Where your rifle/ammo combo zeroed at 25 will hit at any farther range depends on your bullet's ballistic coefficient and velocity, plus the height of your sighting plane, or line of sight, above the line of the bore. In other words, an iron-sighted rifle using X load and zeroed at 25 yards will have a certain point of impact at 100 yards, while the SAME rifle shooting the SAME ammo but mounted with a scope for sighting will hit at a DIFFERENT point of aim at 100 yards.

The only way to know for sure where your rifle/ammo will hit is to shoot it; but a generally-accepted rule of thumb for the typical .308/.30-06/.270-class rifle mounted with a scope at about 1.5" above the bore will hit between 2 and 3" above point of aim at 100, and be close to dead-on at +/- 200 yards. This matters little with big game standing broadside in the open, but becomes critical when the target is smaller. Dramatically change the velocity, or the height of the scope, and this rule of thumb goes out the window.
 
#42 ·
I have a 243, a 260, a 7MM08, a 308, and a 270. All hit around 0" at 25 yards and all hit differently at 100 and 200. Part of the problem is it's so hard to measure exactly where the center of the group is at 25 yards, and even a 1/8" difference at 25 yards can be significant at 100 or 200 yards.

I also keep forgetting where each gun is sighted, since they all shoot different weight bullets at different velocities. So this year I'm going to re-sight all of them to be zeroed at 200 yards, and they all will be no more than just over 2" high anywhere out to 200 yards. (The faster calibers will be less than 2" high.) Then I'll practice a lot at 300 yards to tell how much holdover is needed at those ranges. The slower caliber rifles I use at mostly bowhunting ranges, so they will all be about the same at 25-75 yards. But sometimes I see a coyote or deer out in the field when walking back to the truck, so it will be nice to be able to have a decent chance at a 300 yard shot.
 
#44 · (Edited)
Rojkoh, that sounds like a fun day at the range... I am smiling at all the variables that need to be in place.

With respect to our man in Greengland, Sus Scrofa - that offset scope design you mentioned made me think of the man-machine interfacing in British built combat aircraft. The aerodynamics and physics were and are THE best that science has to offer, I must say. Then the designers remembered -"Oh-me-gosh! A human has to pilot this thing!". This human then sqeezes himself into a cramped cockpit where the controls and instruments are placed where the looms with randomly cut lengths of individual wires ended. You had main systems on the emergency panel, emergency system controls invisible behind the left shoulder and critical instruments (like fuel gauges!) only visible if you wormed your head under the side rack to mentally add up the gauge indications of the needles of eight individual tanks. Now do this while in close formation at night 100ft above sea level onto a target and the leader calls for "fuel check!".

With your side-swiping bullet of that scope position only on the cross hairs at one range no wonder machine guns are required to paint an area... :)
 
#45 ·
Rojkoh, that sounds like a fun day at the range... I am smiling at all the variables that need to be in place.

Dialing in the 2X7 out to 1000 yards luckily only took a day, trying to dial in the 3.5X10 was a headache. Burnt through a case of PMC ball and never got it right even with a lot of shimming. That's why I went back to the 2X7 On offset scope mount like that was a headache with a critical scope. It's why it wasn't adapted even though it was a great scope mount. You could slide the scope off and on and still have it zero'ed.

Used to have two of them, *** grabbed one and I couldn't get it back. Here's what the 1" top strap looks like
 

Attachments

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top