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have a question for y'all, Sighting in a rifle

kyhareraiser

Active member
i've been told by a guy who shoots rifles quite regular that if i sight my rifles )308win& 30-06sprfld )to be dead center at 25 yards thet they will be dead center at 100 yards also..then if i want o zero dead center at 200 yards all i have to do id raise the elevation 6 to 8 clicks and it will be there.. i'm gonna use these to deer hunt and i will be shooting anywhere from 10 yards to 250 yards.. i plan on using barnes tsx and since the price is pretty steep i'm trying o find away to sight thm in without sending a 35.00 box of bullets down the pipe to sight them in.anyone know about this or is he full of hog wash.. i know sending bullets to a target is the best way to be sure and i love to shoot.i guess i could send some cheapo's down the pipe to check it out but then i'd have to test the barnes anyway to be sure.. help me out with suggestions ''please
 

Fugaloo

Well-known member
While I can't back up his numbers, the idea is correct. As the bullet leaves the barrel it is dropping immediately, Therefor the barrel is tipped up a little bit to compensate for gravity. Even though technically is it traveling upwards, gravity is pulling it down from the instant it leaves the barrel. So imagine a gentle arch, with the starting point at your barrel, and the end point at the target. The theory is (and again, numbers will vary) at your short range spot (the hypothetical 25 yards) the bullet is at the same elevation on it's upward advance as it is on the downward turn at the point of impact(let's call that 100 yards). Which would mean that anywhere between 26 and 99 yards the bullet will be above this mark, and outside of those distances in both directions it will be below it. Like I said, I can not back up the exact numbers of 25 and 100 yards as many factors affect the actual trajectory, but the concept is valid. I included a picture and Wikipedia has some good info on the subject if I have not done a good job of explaining it.
 

Attachments

inchr48

Moderator
Moderator
Have you ever used a ballistics calculator like the one found at biggameinfo.com ?

Putting in the bullet velocity, bullet diameter (caliber), weight, and B.C. with a 100 yard zero, it will tell you your corresponding short range zero. That should get you close enough for minute of deer out to 200 yards.
 

skeeterbait

Well-known member
First, what Fugaloo said is exactly correct about trajectory. Use that as a starting point to understand how trajectory works.

Now take it from someone else who has been there and done that a LOT, Sighting your specific caliber rifles in to zero at 25 yards will assure you you will be on paper at 100 yards, but nothing else. You still need to finish the sightin by actually firing at 100 yards. 1.7" high at 100 will get you on paper at 200 yards. You still need to finish the sightin by actually firing at 200 yards. Why doesn't it work like the guy told you? Because I don't know many people who can consistantly put a bullet in the same hole every time at 25 yards and every gun and every shell performs a little differently. Any error at 25 yards is 4 times worse at 100 and 8 times worse at 200 yards. Pick the load you will use to hunt with and sight in with it too. Pay what it takes to get the job done. That is the only way to have confidence in your weapon.

Other recommendations. Do your sighting in on a calm day and use a very stable rest. Since your final sightin will be on a fouled barrel, leave the bore fouled throughout the season. If you have to clean your bore, foul it with a shot after cleaning and hunt on the fouled barrel. If you are going to take shots out to 250 yards, this is critical. When sighting in, dont get in any hurry. Give the barrel time to completely cool after each shot. Your hunting shot is going to be on a cool barrel so you need to be sure your sightin is on a cool barrel also. Sightin on the highest magnification setting on your scope to minimize any variance in the scopes magnification range.
 
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slanttop357

Well-known member
Boy my scope looks pretty level on my gun, I sight my 7MM at 100yrds 2" above center but this year i need to set the targets at 200 and 300 yrds and see where i hit.
 

Grey Taylor

Well-known member
Your scope body may be level but the crosshairs are looking at a slightly different plane. Remember, when you spin those turrets it's not the scope body that moves, it's the interior mechanisms of the scope that move.

Guy
 

MULEY51

Forever Hunting
Don't get into ballistics, but I've set my 30.06 dead center at 25 yards for 40 years and have dropped deer with heart shots from 40 to 400 yards. Just me...
 

BelchFire

I speak fluent Vise-Grip
Admin
You're getting some REAL good advice above. But realize this. When you sight at 200 yards and move the point of impact 1 inch (at 200 yards), it's only moving 1/8 of an inch at 25 yards. So if you want to really screw down the accuracy, you're going to have to shoot at 200 yards.

BUT I realize your cost dilemma (we all share it with you, too). Bore sight it to hit a target at 25 yards and you'll be on paper at 100 yards if you're careful how you do it. It never fails me. Then shoot at 100 yards and take your time sighting in (cool barrel, etc). You should be able to do it in 6 shots; maybe 8. Finally, shoot at 200 yards with NO adjustments. Then, you'll have a firm number as to where it's shooting at 100 and 200, with 25 being a no-brainer. If you sight at 100, it'll be WELL inside the kill zone at 25, no matter where you hit at 200.
 

Val

Well-known member
Skeeterbait is right on, the 25yd zero is an approximation based on bullet drop. Bullet drop is highly affected by muzzle velocity. The muzzle velocity varies greatly between the various calibers and different loads (thus highly varying muzzle velocities). The faster the muzzle velocity, the less the bullet drop in a given distance. This is because gravity has less time to drop the bullet since time is a significant factor affecting the effect of gravity. You must fire at the longer ranges to insure properly sighted rifle..
 

Where's Bruce?

Well-known member
I sight my rifles in based on their effective range. For example, my 22-250 is fast and accurate with little drop between 100-200 yards so I sighted it in at 200. I can pretty much place the crosshairs in the same place on any target within 200 yards and hit it. But my 45-70Govt has considerably more bullet drop so I sighted that one in at 100 yards and use a BDC scope. If you may be shooting to 250 yards in the field then I would recommend practicing at the range at 300 and even 400 yards (as well as 100 & 200) so you know exactly what the bullet is going to do in any situation. And practice shooting off sticks, sitting, offhand...all the ways you will be shooting in the field. You won't have a Lead Sled on that ridgeline so practice for the field. Look at the ballistics of your ammo, realize where they lose velocity so you shooting with enough KE to hit your target hard. Some of the smaller bullets lose their punch quickly between 100-200 yards. because every gun and ammo is different, it is wise to sight your rifle with and practice with the ammo you will hunt with. When you can consistently hit your target at 300 yards even with wind, then you are ready for the field. When you're hunting, there are few second chances...the successful guys have got their rifles dialed in and know precisely what they can expect from them. JMO
 

#1Predator

Well-known member
One shot zero -

1) Bore sight the weapon at 25 yards. This should get you on an 8 1/2 x 11 sheet of paper at 100 yards.

2)Place target at 100 yards. With a steady rest, fire one shot at the bulls-eye on the target.

These next steps are critical:

3)Place the cross-hairs back on the bulls-eye. Secure the rifle so the cross-hairs are on the bulls-eye without human support of the rifle. Make sure the scope adjustment caps are removed.

4)Without moving the rifle, carefully use the adjustment knobs to "walk" the cross-hairs over to the bullet hole from the first shot. (Doesn't this make sense? The bullet hole and the cross-hairs are supposed to be in the same place, right? So why not move the cross-hairs to match where the rifle put the first bullet?)

5)Now, unsecure the rifle, center the cross-hairs on the bulls-eye and fire a second round from a steady rest. Bingo, I'm sighted-in, dead on at 100 yards.

Easy peezy, lemon squeezy.
 

Where's Bruce?

Well-known member
I tried that using a Lead Sled, it's easier said than done. It assumes there is virtually no shooter error and that the rifle in the rest is undisturbed. That's not always easy.
 

jindydiver

Well-known member
One shot zero -

1) Bore sight the weapon at 25 yards. This should get you on an 8 1/2 x 11 sheet of paper at 100 yards.

2)Place target at 100 yards. With a steady rest, fire one shot at the bulls-eye on the target.

These next steps are critical:

3)Place the cross-hairs back on the bulls-eye. Secure the rifle so the cross-hairs are on the bulls-eye without human support of the rifle. Make sure the scope adjustment caps are removed.

4)Without moving the rifle, carefully use the adjustment knobs to "walk" the cross-hairs over to the bullet hole from the first shot. (Doesn't this make sense? The bullet hole and the cross-hairs are supposed to be in the same place, right? So why not move the cross-hairs to match where the rifle put the first bullet?)

5)Now, unsecure the rifle, center the cross-hairs on the bulls-eye and fire a second round from a steady rest. Bingo, I'm sighted-in, dead on at 100 yards.

Easy peezy, lemon squeezy.
I do pretty much the same thing. I sight over sandbags or whatever and then clamp the rifle in a gun vice clamped to the bench and move the crosshairs to the group. It gets you on target with a minimum of shots.
 

#1Predator

Well-known member
I tried that using a Lead Sled, it's easier said than done. It assumes there is virtually no shooter error and that the rifle in the rest is undisturbed. That's not always easy.
You're right, it isn't exact because of human error but it saves me a lot of ammo over other methods. I use a Lead Sled as well. Two 30# lead ingots on the Sled and several bungee cords to make sure there is as little movement as possible when I am ready to "walk" the cross hairs to the bullet hole. I used this method last Saturday to zero/test some new loads in my .22/250 using 36 grain Barnes Varmint Grenades at 200 yards. Next stop.....coyote country.
 

Where's Bruce?

Well-known member
I have four 25lb lead bags in mine, how do you secure the rifle with bungees? I'd like to see a photo of that. Fascinating idea.
 

BigAssWhiteBoy

Well-known member
Your on the right track with using the cheap stuff to sight in but just use it to get on paper. there is a lot of good advice on this thread but your buddies advice may be a little off. 6 to 8 clicks on his scope may be 1 1/2 - 2 MOA or it may be 3 - 4 MOA depeending on the scope. Figgure out all the specifics of your rifle and ammo you will be using, like previously said, FPS, Crono distance, sight hight, BC, Bullet diameter, and get all the atmospheric data, Elevation air temp humidity and pressure, i may be forgetting a few things but you get the picture, and go to JBM Calculator. Its the best ballistic calculator out that i know of, they even have an app :) but put all that in and you can see what your bullet is doing at what distance then you can figgure out what you should zero your rifle at and what your adjustments will be farther out. Then after you have done all that put it on paper to check it for sure but JBM will save you some rounds trying to get on paper at greater distances. Also check oyur cheap loads to your your hunting round, get the same grain and it might match up prety close so you can use that to practice with. i got lucky and found one that matched up. IMO a 200 yard zero is the way to go for a rifle of the that caliber for deer hunting. good luck and happy and safe shooting.
 

#1Predator

Well-known member
I have four 25lb lead bags in mine, how do you secure the rifle with bungees? I'd like to see a photo of that. Fascinating idea.
I only use the bungees when I'm making the adjustments on my scope. This pretty much anchors my rifle so I don't move it while adjusting the cross-hairs. I use three short bungees (one over the barrel and front pad of the Sled, one over the barrel just under the scope, and one over the stock just in front of the rear stock support of the Sled). Each one goes over my rifle and entirely around the Sled. The ends of each bungee are hooked together under the Sled. I try to space them equally along the rifle, depending on the scope mount. No bungees over the scope for obvious reasons.

The trick here is getting the bungees in place while keeping the cross-hairs centered on the bulls eye of the target. It takes some time to get everything just right. Once it's done, the rifle is all most immovable.
 

TonyS

Well-known member
+1 #1 Predator. That is the way I do it. But I don't bungee anything down. Use the sled to zero your rifle then shooting sticks, etc. for practice.
 

HuntnBrew

Well-known member
While I'm not saying it's imposible to bunge your rifle to your sled it's a good idea to know what your gun will do if your barrel is floated and you hold it down. Pay the money for your ammo and shoot it. It sucks to drop the money but it's better than spending $200 buck on gas supplies and other stuff to miss your shot when you have it and go home empty handed.
 


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