Discussion in 'Scopes & Optics' started by esilva208, May 16, 2015.
So what a good yardage to sight at 100,150, 200?
I have Remington 783 .270 with a 4x16x40 scope
Generally, sighting in for 200 yards will give you close to the longest distance where your bullet will hit the target if you aim for the middle. If you don't have a 200 yard range available, it's a simple matter to check how high the trajectory would be at 100 yards with a 200 yard zero and just adjust your sights to hit the 100 yard target that high above your aiming point.
Luckily I have a 200 yrd here
Center your cross hairs, then have it bore sighted or do it yourself. Shoot it at a large bull with a 3/4'' dot at ten or fifteen yards, bring it into the 3/4 dot with just a few rounds at close range. Then move out to longer range.
Never fish around at 100 yards or more with a new mount, unless you just like to waist ammo.
Assuming you are using quality full power 130 gr hunting ammo, I would suggest sighting it in to hit 1 inch high at 200. That should extend your range to 300 without having to worry much about bullet drop. Once sighted in 1 inch high at 200, shoot it at 100 yards, and note how high the shots are at that range.
The 270 is a pretty flat shooting cartridge.
Before you shoot a 100 or 200 yard target you need to be on the paper.
So do that first at 10 or 15 yards.
Center that up and you can move out to 100 or 200 or more yards any time.
I like my hunting rig shooting 3.5 inches high at 100 yards that puts me dead on at 300 yards and 27 inches low at 500 yards.
We need to know your expected hunting distances but it is fairly simple to establish the come ups for what you want. For example:
Dead on at 100 yds will need 1.25 inches up for 200 yds.
Dead on at 200 yds will need 4 inches up for 300 yds.
Adjust to exact center as necessary.
As far as actual sighting in of a rifle I am not a fan of wasting ammo when I am trying to accomplish a sight in task. It is fairly simple to boresight at 50 yds. for those with bad eyesight. It can also be done at 100 yds.
If you use 50 yds. just use a standard 100 yd target with the black field around 6 inches in diameter.
1) Stick your rifle on a rest and remove the bolt.
2) Align the scope to dead center on the target.
3) Look down the bore and you will easily see where the target is in relation to the bore.
4) Adjust the scope settings until the bore sight and scope appear to match.
5) Aim dead center and fire your first bullet.
6) Note the hole and realign your scope to dead center again on the target.
7) While holding the scope dead center move the cross hairs to the hole. Do not move the rifle while you do this.
8) Once the crosshairs have been moved to the hole realign your scope back to dead center and fire once more. The bullet should be just about dead on.
9) Move the target out to 100 yds and fire a round. Adjust scope to dead on and confirm with a shot.
Note: MOA is approx:
1 inch at 100 yds
2 inches at 200 yds
3 inches at 300 yds
4 inches at 400 yds and so on up to whatever distance you plan to shoot. We can stop at 1000 yds.
10 inches at 1000 yds.
The reason I say approx is that MOA = Minute of angle = 360 degrees which is NOT quite 1 inch but close enough for what you need.
MOA relates to bullet movement at distance.
A scope with 1/4 clicks is 4 clicks = 1 inch at 100 yds with each click being 1/4 inch crosshair movement in either axis.
That same scope at 200 yds means 4 clicks = 2 inches of cross hair movement or each click = 1/2 inch.
That same scope at 300 yds means 4 clicks = 3 inches of cross hair movement or each click = 3/4 inch.
And so on. It really means you need to be able to look at windage for a given distance to know how much each click more the crosshair right or left.
My Night Force 12X42X56 has 1/8 inch clicks which give me finer adjustments out at distance. With hunting you should be in the boiler room easily with a 1/4 inch scope over the distances you will be shooting.
Just about every bullet manufacturer has some sort of ballistics calculator that can give you the come ups for the particular you will be using. Reloads generally know the bullet coefficient of the slug they're using and they also spend time over a Chrony to determine bullet speeds when calculating comes up.
Sorry if it might be too much info but it might make for some reasonable reading on the forums...
200 yards. That would be called the "point blank" zero for your rifle, meaning any shot out to your zero will have +/- 1.5" of rise or drop.
Measure how far the sight axis of your scope is. I would speculate a 40mm objective is 1.5" above bore.
Looking at ballistics for 130 and 140gr 270Winnie bullets,
35 yards zero
120 yards, ~+1.5"
200 yards, zero
300 yards, ~-6.5 inches (it starts to drop fast)
I've never heard anyone define point blank before as being only +/- 1.5 inches.
When the legendary hunter Jack O'Connor sighted in his .270, he said that he sighted it in for a +/- 4 inches point blank. However, most people that I have seen refer to point blank have defined it as being +/- 3 inches. You are the first person that I have ever seen define it to be only +/- 1.5 inches
With the heavy 130 gr handloads that he used, O'Connor claimed that gave him a point blank range of about 340 yards, with the bullets hitting 3 inches high at 100 yards, and almost 4 inches high at 150..
And I can confirm that seems possible. Hornady's 130 gr SST Super Performance .270 Win load pretty much duplicates the 3,200 fps muzzle velocity that Jack O'Connor said that he managed to get with his maxed out handloads.
Anyway, I ran some calculations using the trajectory calculator on Hornady's website on this load. This is how it came out with a 250 yard zero:
One can see that with a 250 yard zero with this particular load, one could easily have a point blank range of 300 yards, using a definition that point blank is +/- 3 inches.
Now the above load is expensive premium ammo. If we instead plug in Hornady's much cheaper .270 Win 130 gr Interlock load at a more standard muzzle velocity of 3.060 fps, a 225 zero will give one a point blank out to 275 yards, using +/- 3 inches as the definition of point blank:
Jack O'Connor was quite an exceptional hunter and marksman. For him, perhaps a +/- 4 inches point blank made sense. For the rest of us, I think that 3 inches is a more practical option.
Going with just 1.5 inches, though, as you have done here, seems like going too far in the opposite direction, in my opinion.
Lance, I stand corrected. 1.5" is my recollection of "point blank" defined for rifles.
Me, I don't even think about point blank. As they say, "know your dope."
P7id10T - Do a search on point blank.
It gets interesting.
Thanks for the heads up. Good explanation here: http://www.exteriorballistics.com/ebexplained/5th/50.cfm
3" high at 100 yards puts you close to 3" low at 300 is what I recommend if your going to hun the woods as well as the open country.
Man y'all think too much.
200 yard zero puts the bullet in the vitals from about 50 yards to 300 yards with your 270
But what do I know?
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