.338 Win Mag and .308 Win sight in?

[Fuzzifus]

Longtime lurker, first time poster.....I searched for an answer to this question but couldn't find an exact answer so here it goes........

I am getting ready for Michigans rifle deer opener. I use these 2 rifles for the majority of my deer hunting:

Weatherby Vanguard Synthetic Chambered in .338 Win Mag
Federal Vital Shok 210 gr. Nosler Partition

Ruger M77 MKII Target CHambered in the .308 Win
Winchester Supreme 168 gr. Ballistic Silvertip

Around here I have absolutely no place to shoot a rifle past 100 yards, though where I hunt I can shoot maybe 400 yards (though I would never likely shoot that far). I cannot sight the rifle in practically at this location though. So given the conditions, I need to sight in the rifles at 100 yards for further yardage accuracy.

My thought with the .338 is to zero the rifle for 250 yards. I would use this rifle only in the longer food plot I hunt, with shots nearing 300 yards and would lean towards neck shots on does, as to prevent massive damage.

I would thus need to sight the .338 in +3.1" at 100 yards to be zeroed at 250...correct?

As for the .308, this is my more all around deer shack gun.....I was planning to zero this at 200 yards. So at +2.1" I should be zeroed at 200 yards, correct?

I am trying to minimize hold-overs and unders and think these ranges would be the most effective. Just want to make sure I have my numbers right and am heading the right direction......thanks for the help!

 

[35 Whelen]

First of all, this site is your friend when it comes to all questions ballistic.

Regarding the 338, the 210 gr. Nosler (ballistic coefficient: .400) at 2830 fps as loaded by Federal, would need to be sighted about 3.4" high at 100 yds. to be on at 250. It would be a little over 18.5" low at 400 yds. (Bear in mind that so-sighted, your bullet would be around 4" above the line of sight at 175 yards thus increasing your chances of shooting over the top of a deers back.)

Regarding the 308, the 168 gr. Winchester bullet (ballistic coefficient: .474)would need to be 2.35" high at 100 yds. to be dead on at 200 yds. It be about 25.5" low at 400 yds.

If I may ask, have you ever shot at 400 yds.? I've shot at some pretty extended ranges and I think it's be exceedingly difficult to hit something as small as a deers neck at that range.

If you're concerned about the 338 WM wrecking meat, why not just use the 308? To me, if the range at which the game will be shot is known, what difference does it make if you have to hold over 15", 18", 25", etc.? Plus the 308 wiould be more than sufficient for a deer at that range.

Todays inexpensive rangefinders have almost negated the need for laser flat shooting cartridges. If we can establish the range of the game, and know how to properly use our crosshairs to determine holdover, then the amount of holdover shouldn't really matter.

Good luck,
35W

 

[LoonWulf]

Id also suggest the 08 over the .338 at that range. If your dead set on using your .338 id suggest a bullet that expands slower, E-Tip or Accubonds for instance. Can you practice at 400 at all? making hits at that range, even if you know your trajectory, can be a challenge without practice.

 

[Fuzzifus]

The .338 is a gun I would like to get some experience behind beofre heading west next year. As for the neck shot, that would only be in the case of an animal coming into range much closer than I expect, say 150 yards or less. I have a couple of bruiser bucks I have been bowhunting, and should I see them at 300 yards in my food plot known as "The Big Field", I thought a well place round behind the shoulder would end all doubt immediately. In the plots where my range maxes at 250 yards or so, the .308 is going to be the tool of choice.

THanks for the link to the ballistic calculator, I will use it in the future. I am assuming you did as I did and simply set the zero for 250 and see what the shoot over at 100 is? Obviously the sight height is dependant on semi accurately determining the zero as well....correct?

 

[Fuzzifus]

Also, a last piece of the puzzle.....

THe .338 has a Vari-X III with a 50mm Obj. THis puts the scope height (sight height) from center of the bore to the center of the scope at just about 2".

As for the .308, it has a Vari-X II with a 40mm obj. This gun runs about the standard 1.5" center of bore to center of scope.

Do these measurements seem correct...? I assume they are and they obviously make a difference.

Lastly, I have shot out to extended ranges quite extensively in the past. I was comfortable to 500 yards on hunts in New Mexico, Colorado, etc. I know there is no substitute for shooting at a target 400 yards away, but I simply have no way of doing so in mid-Michigan. I have been sucessful at shooting rifles at 100 with a + elevation to zero them for a further yardage, but this was with the help of my former gunsmith, who has since passed. He was an incredible wealth of knowledge.

 

[MtnCreek]

Sight height will make a difference. I didn't see the link to the calc, but I use one at Handloads.com. You can adjust sight height on it (also elev, temp, ...)

 

[Art Eatman]

If you're just getting started with your sight-in: I'd start at 25 yards. One shot at a time. Get the .308 to dead-on and the .338 maybe a half-inch low. Then go to 100 yards and shoot a three-shot group. Then, adjust the scope to move the group's center to the aiming point.

For both rifles, I'd go for two inches high at 100 yards. That will be pretty close to dead on at 200 and maybe six inches low at 300, give or take an inch.

The .308 will have about two feet of drop at 400 with that sight-in. I don't know about the .338, but probably not much different.

 

[HKGuns]

Art's approach is exactly what I use when at the range.

I'd sight them both in dead on for 200 yards and sight in at 100 to be 1.7-2.3" high depending on the round you are using and other minor variables.....The bottom line for Deer hunting is that "most" .30 rounds 2" or so high at 100 will have you sighted in to be dead on a 200.

Your ammo box should have all the details for you to plug into one of the many ballistics calculators out there. Just make sure you hunt the round you sight in with.......After losing a deer due to ammo differences I am so anal as to buy the same lot number of bullets en masse and I shoot only those cartridges when hunting. (That is obviously over kill but I am not going to learn a hard lesson twice.) It is hard to believe but cartridges "can" shoot very differently from what you sighted in with.....

 

[45crittergitter]

Use MPBR.