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Sight-in Question
Posted: Mon, 05 Aug 2013 11:14:44
by Steelhoss
I just bought a new Leupold VX 3 Rifle scope with the Boone and Crocket recticle and mounted it on my Ruger M77 300 Win Mag.
My question is this:
I am shooting a .30 caliber 125grain Nosler Ballistic Tip with 74 grains of IMR-4350. What range should I sight in at?
For instance: If I sight in at 3" high at 100 yards will my shot still be good at 300 yards? if the target is at 500 yards which cross hair on the reticle should I use, or would I just aim high?
Confusing!
Can anyone point me in the right direction or perhaps evenJust a bit of information would go along way to getting me straightened out!
Thank you folks!
Todd
Re: Sight-in Question
Posted: Mon, 05 Aug 2013 18:54:17
by dmharvey
How are you planning to use the rifle? I'd think that would determine the range you'll want to zero it at. There are some videos on YouTube that cover this topic pretty well. Good luck!
Re: Sight-in Question
Posted: Mon, 05 Aug 2013 20:07:32
by AlanM
There are online ballistics programs that will give you more information than you could possibly want, or need for that matter. Just google "rifle ballistics calculator free".
The really critical measurement is the center to center distance of the optics to bore. That is, how high is the scope over the barrel.
You'll need to have a good value (or guess) for muzzle velocity, of course.
This will probably tell you what you want to know:
Bison Ballistics Calculator
Re: Sight-in Question
Posted: Mon, 05 Aug 2013 20:30:51
by AlanM
Also, if you're planning to use this load for deer hunting you probably should read this:
Please DO NOT use ballistic tip bullets on deer.
Re: Sight-in Question
Posted: Mon, 05 Aug 2013 20:53:21
by gunderwood
125gr BT in a 300Mag? That's a bit light, but I have one set up that way as well (search 300 Varminter on this forum). Technically it's a .300WSM, but close enough. What's the reason for the light bullet?
Firing up QuickLoad for a 24" barrel and 74gr of IMR-4350 I get 3264fps. Realize that QL is a model, so it's only an estimate, but generally fairly close. I like using
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi but use any that you like.
The best sight-in distance really depends on how/what you want to use it for. There are several targeting concepts such as Max Point Blank Range, Danger Space, etc. that make sense depending on your use. Many people go simple and zero at 100 yards because of the abundance of 100 yard ranges.
Let us know what your plans are and we can assist better.
Re: Sight-in Question
Posted: Mon, 05 Aug 2013 21:03:30
by gunderwood
BT, particularly light weight ones, are not good matches for large magnums, etc. I load mine in .300WSM, but for long range varmint (avoids the ricochet problem). BT are a light bullet design and should be avoided for heavy game, but can work fine on deer, a thin skinned medium game, if not pushed too fast. The problem is you have people loading the lighter bullets in 06's and Mags which is pushing them well beyond their intended velocity range. My .300WSM can push a 125gr BT to just over 4000fps. Absolutely explodes varmint. The 110gr V-max are a bit "weaker" yet...at 4200fps it won't penetrate a crow at 250 yards, but wings an feathers will fly ten yards away!
Re: Sight-in Question
Posted: Tue, 06 Aug 2013 21:25:15
by davsco
OP, you really should shoot your rifle/load at the various distances you expect to shoot it in the field, rather than just relying on trajectory tables. sight it in for 100 and see what it actually does at 25, 50, 200, 300.
re ballistic tips on deer, they've been my favorite by far, explosive peformance. i probably wouldn't use on thicker-skinned game.