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Question sighting in scope

4K views 23 replies 9 participants last post by  Peter 
#1 ·
I'll be sigting in a scope today (Leopold VXIII 3.5x-10x 50mm) on 308 caliber.

The range is a 100yrd max so given the trajectory of a 308 what is considered the best overall position to hit paper?

For example sight in for 1 inch high at 100 yards etc..

Most real life shooting would be under 250 yards

I know bullet weight makes a difference ect...just wanting some opinions of a good general sight in mark on target when limited to 100 yrd range to sight in scope so that I know if the shot is 150 yards I am fairly dead on or possible need to shoot 1.5 inchs high at 250 to hit mark....just looking for a general theory.

thanks
 
#2 ·
There are sites(can't remember which one's right now) that will give you trajectory charts for different calibers, generally you want to sight in a centerfire at 200 yds, and if your shot is less than 200 yds it'll only be at most an inch or so high. I bought a .270 Winchester(which is a flatter shooting caliber than .308) and mine is sighted in at 1.5 inches high at 100 yds. PS, I don't know if you have one, or have the extra cash to buy one, but I highly recommend getting one of those laser bore sighters from Walmart, I bought one for $40, believe me it will save you $ and a LOT of frustration in the long run, its one of the best investments I've made for my firearms. Good luck
 
#3 · (Edited)
First off...

Do your initial cutting paper at 50 yards.
Get a sandbag and lay your rifle down upon this.
You're trying to see how well your rifle shoots--not how well you shoot.
So lock the weapon down as well as possible.

Go to a gun-shop and get one of those day-glow target dots.
Use this on your target to help with acquisition.
This will greatly improve your groups.

At 50 yards get your elevation and windage adjustments down with 3 shot groups.
Let the rifle cool down suffeciently between each shot.
If it heats up, you will get target drift--barrell warps when heated.
You want a "cold zero."
Adjust your windage and elevation between groups.

When your scope is zeroed at 50 yards move the target out to 100 yards.
Again fire a three shot group.
If the group is far to one side or the other--you have a problem with the scope mounting.
It may not be perfectly in-line with the barrel--gunsmith work is required.
If you get a good group (and it should be slightly lower than your 50 yard group), adjust your elevation.
Again let the rifle cool between shots (remember cold zero).

When you get your 100 yard elevation and windage move the target out to 200 yards.
Fire another 3 shot group.
Note how low the rounds impact the target.
This is the ammount that you want to "hold over" when shooting at that range.
Also note the windage--did it drift off more than 2 inches?
If so, you have scope alignment problems.

Repeat the process at 250 and 300 and note your "hold overs."

You make a little chart and paste this to the stock for quick reference.

After you zero at 100 yard you can also use/borrow/buy a chronograph and measure your round velocity.
There are programs that will calculate your bullet drop.
But I only sugget this for custom loads/reloads--factory ammo will not be consistent enough.

.308 is a powerful round, and at 200 yards you will not get a lot of drop.
It becomes very noticable at 300 and beyond.

So remember to bench rest shoot your groups off a sand bag for maximum performance.
And you will need a spotting scope or good binoculars to see the targets.



You performance will depend on your rifle and ammo quality.
You should be able to shoot 1 MOA (inch groups) at 100 yards.
My Rem 700 shoots just over 1/4 MOA using 175 grain A-Max, moly coated (match grade stuff).

I have a custom ballistic elevation knob made especially for my match grade loads.
It's marked in yards so I only have to click in the distance without calculating clicks/distance thing.
Hitting a six inch diameter metal target at 600 yards is quite easy (800 yards also).


What kind of rifle do you have?
Is it new? Used?
If new you may have to break in the barrel first.

T
 
#4 ·
Pick up a shooters bible. They have ballistic charts for most factory loaded ammuntion. Zero the rifle at 100yrds. Check the ballistic chart for the particular load and manufacturer you will be using to see how far the bullet drops at various ranges. Most of the data is based on 100yrd zero, the data will tell you how far the bullet drops, then you know how much higher you will need to aim above the target. At least that is what I have done. I will keep checking back to see if someone has better advice.
 
#5 ·
The range that I will be going to later today in indoor and 100 yrd max so I will get it to 100 using the steps described above. Next weekend I can make it to an outdoor range to finish off on the longer ranges.

This at least gives me some good pointers as to get started and to make sure the new scope mount and rifle are accurate.
 
#6 ·
Something else I forgot to mention, that I'm VERY pleased with are the scope rings/base that I use, they are the DNZ Dednutz one piece base/rings, you should check 'em out, these are the ONLY rings/bases I'll use from now on, and they make putting your scope on a lot easier too. You might want to check out Chuck Hawk's site, he's got a lot of ballistics/trajectory stuff on there, and good info all around.
 
#7 ·
Use some loctite on all of the screws. The Mount, the rings etc. Just a drop on each one should do it. I am speaking from experience. Nothing is more frustrating than sighting in a rifle, only to get home and while cleaning discover that something came loose and you need to start over again. Or for my brother, his came loose during an Elk hunt. His 7mag first, then his 30/06 that he brought for a spare. Neither rifle had Irons.
 
#8 ·
The dednutz is actually the one I just put on. This will be my first time to try them but they seem to be constructed well and I liked the one peice design.

I agree about the loctite, good point I did not think about using that but I will.
 
#10 ·
Just cut through all the bull**** advice from armchair snipers and hunters and gun magazine wizzards. Real world hunting and combat is done through PBR sighting and accurate range estimating....not hold over. A 147 grain ball round at approximtely 2800 fps , sighted in at 0.50 inches at 25 yards and confirmed to be 3.63 inches high from a 6 o'clock hold at 100 yards will give you a 4 inch approximate PBR to 300 yards; roughly a 255 yards zero. This means your shot will be no more than 4.25 inches high at 150 yards when holding 6 o'clock on center of mass and no lower than 4.35 inches at 300 yards when holding 6 o'clock at 300 yards. Forget hold over and learn to use a range finder or mil dot mental calculations to accurately estimate range. Forget the armchair wannabe snipers and video game hunters and gun mag writers fantasy self glorifying advice. gbu and yours
Wow that is great advice, try using a range finder on a running elk or deer.
Thanks for insulting everyone who posted before you.
 
#11 ·
Once you have acertained the range is 300 yards and knowing one mil dot is 10 inches approximately at 300 yards, hold 1/2 mil dot below the cross hair intersection on center of mass and your shot will not be 4 inches low but dead on. On an animal the size of a dear, 4 inches lower than center between brisket and shoulders is a decent shot in itself.

Yeah, right... and this guy probably doesn't have a mil-dot scope.
So why all the fancy schmanzy tech talk.
The way we and I gave him is the easiest way for shooting at 300 yards and less.

And this guy probably doesn't have a BDC or a mil-dot scope, so hold over/under is the way to shoot this rifle.
And he is not using match-grade ammo.

I do have a mil-dot which I use for range estimation (along with my laser range finder), and it is not easy setting up a shot at long ranges.

This guy wants some quick and dirty basic solutions for short range shooting, not sniper techno-babble-talk.

Keep is simple stupid.

T
 
#12 ·
In my "Yuth" well before these new fangled computers the general rule of thumb was 3" high at 100 yds which IS ALMOST, nearly, sorta, Kinda like zero at 200 yds and 3" low at 300 yds using rifles with a muzzle velocity of the .270 Win yo .30/06.

Also, do not even think of starting to sight in at 100 yds! Shoot 0" high at 25 yds and try for the 12:00 line, Then move to 50 yds and try the same thing buy not changing any knob settings (you'll be about 1.5” to 2" high). Now take it out to 100 yds and try again and make elevation adjustments to bring it to about 3.25” to 3.5” (or whatever the trajectory computer says it should be) but still on the 12:00 line--3 shots 25, 3/50 and 3/100 = 9 shots and you're sighted in (You can eliminate the 50 yds if you want but I don't.)

These are hunting settings not target, sniping or BR.

Fire off a sand bag or BR front rest; take your time between shots and relax.

The info on the mil-dot, albeit helpful, is only for mil-dot scopes and don’t pay it any attention unless your scope has such a reticle and as the majority of scopes sold are hunting models, I don’t yours will.

On a sporter configured barrel a little device that is cheap and works great is a barrel de-Resonator from LimbSaver—about $25.00 and worth every penny. It makes sure your barrel harmonics—vibrations—radiate at the same frequency each time you fire and makes really small groups possible. Best part, you can switch them off between different rifles.
 
#14 ·
Lastly, a person's desire to read animosity into a post guarentees they will. Atleast one did so. I referred to no one but gun mag writers and wannabe experts. The media is full of such. Why should any reader assume I was directing that to them?? Perhaps that question is better answered by the offended person than I.
Just cut through all the bull**** advice from armchair snipers and hunters and gun magazine wizzards.
. Forget the armchair wannabe snipers and video game hunters and gun mag writers fantasy self glorifying advice


It seemed to me that you are directing the animosity to everyone posting.
If not who were you directing it at? I don't know of any "Armchair Snipers" who posted on this thread. There are alot of us "Hunters". Is that so bad to just be a "Hunter".
 
#15 ·
"Lastly, a person's desire to read animosity into a post guarentees they will. Atleast one did so. I referred to no one but gun mag writers and wannabe experts. The media is full of such. Why should any reader assume I was directing that to them?? Perhaps that question is better answered by the offended person than I.
Just cut through all the bull**** advice from armchair snipers and hunters and gun magazine wizzards.
. Forget the armchair wannabe snipers and video game hunters and gun mag writers fantasy self glorifying advice"


It seemed to me that you are directing the animosity to everyone posting.
If not who were you directing it at? I don't know of any "Armchair Snipers" who posted on this thread. There are alot of us "Hunters". Is that so bad to just be a "Hunter".
 
#16 ·
newone

Hey newone, just out of curiousity, what experience do you have that makes you such an expert? And obviosly you've never hunted before if you've never shot at a moving target/animal, while I will agree, I strongly prefer a stationary shot, but sometimes they don't cooperate. And for someone taking shots at less than 200 yds, all your babble about mildot scopes is useless. If you haven't noticed, you did offend all who posted before you, none of us are/were proclaiming to be experts/snipers like you came off sounding, and out of all who've posted your'e probably the most likely to lacking in rifle shooting abilities in the first place.
 
#17 ·
just bought a Sightmark Magnetic universal lasor boresight from SPG for $35.00 that attches magnetically to the end of the barrel..anyone use one yet.

all this tech-no jargon is non-sense. KISS. I am not an expert and enjoy reading everyone's input. This is an awesome site..Lock and Load....
 
#20 ·
I have read and reread my post. Three from chat read it and none said it was anything more than a condemnation of gun mag writers. You should reread it, before I pull the post so as not to allow anyone else to feel offended ,and see that it does not mandate mil dot scope usage. It simply states PBR sighting method and uses mil dot reference to explain that there is no need to play 'hold over'. I will pull the post. I in no way admit to being insulting to any other poster, just gun mag writers. As to my experience, it is of no concern of anyones. Personally, I do not believe the autobiographies I read here or anywhere touting military service and hunting prowess and will not engage in that myself. In summation, consider for a moment, you wanted to feel offended so you read into it intent. I can get no one else who I have asked to view it to confirm your or others perspective. I cannot apologize for what I did not do. However, to make you happy..I will pull it soon and mark a few members for future reference as not to reply to. GBU and yours
 
#21 ·
Well, newone, I am now an armchair sniper due to age and infirmity but I was one during the Yom Kippur War in an Israeli Sayeret Company firing an old Mauser K98 rebarreled from 7.92mm to 7.62mm and with the Nazi & Wehrmacht proofs over stamped by IDF. It wore an old Schmidt, about 4x35, scope with just one hash mark on each line vert & horz. The top and both sides with thick posts but the bottom one was a fine wire--different but after awhile very effective. I had a similar setup when I went with the border guards anti terrorist squad. I held tzamal (Sgt) NCO rank in both cases.

Now I'm part owner of a fly-in fishing and hunting lodge in Arctic Canada near Hudson's Bay and I'm also a licensed guide. I normally spend about 270 to 280 days a year being around hunting and fishing. For a hobby I collect books, firearms and edged weapons--antiques not replicas and just started collecting bamboo fly and casting rods! My goal for hopefully this fall (2009)or next spring (2010) is to make a killing shot on a rodent at 3.218KM or better! No, I am not crazy, insane or demented.

As to my experience, it is of no concern of anyone’s. Personally, I do not believe the autobiographies I read here or anywhere touting military service and hunting prowess and will not engage in that myself.
It helps to know from whence you are coming from, doncha know! You could be a 15 yr old Medal of Honor player, the reincarnation of Elmer Keith or the Gunkid trying on a new persona...If you're going to make such bold statements it's nice to know that you have some first hand experience with what you're writing about. Yes, I take biographies with a grain of salt until I can make an assessment of the person's knowledge whether they can back up their claims then I'm a little more outgoing.

FYI, Copping attitude like that gets you a collective WTFC = Who the f*ck cares!
 
#22 ·
Seems like me original post stirred things up a bit....

Well I took much of the various advice and got it sighted in. I am happy with the new browning x-bolt with Leopold combo. Saturday I got it sighted in using the 25-50-75-100 yrds method with three shot groups and allowed about 5 mins between rounds fo cool off. Although I am now stuck in Tampa, FL shooting at paper targets...I grew up in the back woods of TX and shot at "moving" targets for many years. I am not familire with the usage of all the mill dots etc. but it had been many years since I had to sight in a scope from scratch so thanks for all the help. Unlike back in TX, I had set up a range up to 300 yrds and knew exactly how high or low to shoot based on how I had my scope sighted and had a good eye for estimating the distance to the target. I was just stuck with only having access to a 100 yard indoor range and was looking for a good rule of thumb for a 308 using 150 grain (off the shelf) ammo as to where I wanted my bullet to hit so that I know where to expect my hit at 150,200, etc. I am no sniper and would never claim to be.

After all is said and done, I used only a bi-pod that I have set at four inches and that was my BR. When finish with the adjustments, and with a fresh target, I put 9 shots (shooting 3 at a time with a few mins to cool down) and kept them all placed within a one inch square. I sighted in for about 1 inch high at 100 yards.

Thanks again for al the help...like I said it has been a while since I adjusted a scope from the start. Now I just need to find a good place to hunt.
 
#23 · (Edited)
If you happen to have a a mil-dot scope, range finder and all that jazz good on you... my M24 SWS has all that fancy stuff(it for duty purposes.... But for the average JOE (I'm included) I dont have the money to shoot 100'ds of rounds to get good DOPE and money for a mil-dot scope. I would recomend 1 of 2 things. sight it in at 100yds. do this by using a bipod/sand sock. and PRONE. and of course shoot out to 300-400 yds. Most hunters wont take shots this far. Record where you think you shot and where your shot was. and shoot 3 rounds/ check your target. record wind/temp ect. and shoot alot. Another recomendation that alot of sharpshooters use is sight your rifle in at 400yds and use hold off. Alot of my instructors used this method. differences are: there scopes were sighted in at 100yds and were set to 400yds, and they had mildots to used proper hold off... of course this wouldnt work well if your optics didnt have mildots. (I dont use this method, I dont particularly care for it.)Remember 1 MOA @100yds = 1", 1 MOA @ 200yds = 2", If your off 1MOA at 800 yds you'd be off of your target 8" if you take a center mass shot you still should hit a man sized target.(Avg person is 24" shoulder width and waist to shoulder is also 24".... ECT. MOA's are sometimes refered to as "CLICKS". most hunting rifles are set at 1/4 MOA, So its a pain in the butt to mess with them. most Sharpshooter scopes are set in 1/2 MOA for windage and 1 MOA for elevation. during school we never let our rifles "coo" I dont think its that big of a deal... HOWEVER your first shot "the one that counts" WILL ALWAYS BE DIFFERENT FROM ALL OF YOUR FOLLOWING SHOTS ALWAYS RECORD YOUR COLD BORE SHOT. For example on my M24 my shot is consistantly high 1" and left 2" from center @ 100yds. therefore i have to take that into account when i shoot it so i correct it for the first shot. then I take the windage/elevation correction off. we also use 168gr LR or match grade ammo. Good luck...
 
#24 ·
Well if it's a newly mounted scope and not bore sighted, I'll usually start at 25 yards and get the point of impact and point of aim to the same spot. I pick 25 yards to start with because over the years I found a few scopes that wern't even on the paper at 25 yards!
At 25 yards it's a rough zero and seems that for MOST rifles it will get you on the paper at 100 yards. Once you are on the paper at 100 yards, it's pretty much a matter of fine tuning from there...
The whole process is pretty easy and straight forward, Though I'd reccomend using a range facility if theres one close by, because they usually offer all the amenities, benches bags spotting scopes, targets and such...
Peter
 
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