Sighting In a Scope for Squirels

H

harokyle

Inactive
Hi yesterday i sighted in my 22lr. with a 4x scope. I sighted it in dead on at 50 yards. Im goung to be squirrel hunting with it and im wondering if it will hit dead on or close to it at 25 or even 15 yards or if it will be high or low. I would have just shot it at 25 and less yards to see for my self but the range i went to only allowed pistols at the 25.
 
Yep, it can be low at close ranges.
Mine is a high powered rifle scope, 4X fixed, on a Ruger 10/22.
If they are real close and I don't hold a bit high I will kick up dirt into their bellies. At 25 yards they are ded.
 
If the scope axis is 1.5 inches above the bore and you shoot standard velocity long rifle such as CCI standard velocity ammo, 1070 fps at the muzzle and 890 fps at 100 yards, you can expect the following for the rifle zeroed at 50 yards.

0 yards -1.5 inches
5 yards - 1.0 inches
10 yards -0.5 inches
15 yards -0.2 inches
20 yards +0.1 inches
25yards +0.3 inches
30 yards +0.4 inches
35 yards +0.4 inches
40 yards +0.4 inches
45 yards +0.2 inches
50 yards zero
55 yards -0.3 inches
60 yards -0.8 inches

beyond 60 yards, the bullet starts dropping fast and hits about 7.7 inches low at 100 yards, but for all practical purposes, you are point blank between 10 and 55 yards. This is why 50 yards is a good zero range for a hunting .22 long rifle. Zero it at 100 yards and you will shoot over everything that's between 15 and 90 yards.

I got these numbers from the JBM online ballistic calculator by plugging in the muzzle velocity of the CCI standard velocity bullets along with a ballistic coefficient of 0.112, a coefficient I got by trial and error, plugging in different BCs until I found one that gave approximately the published 100 yard velocity.
 
Hyockle, I'd just take that rifle out and practice at all those ranges, that way you'll be absolutely sure what the holdover will be.... Down in the "boothill" of Missouri some of the tree's are pretty tall, so I sighted mine in for about 60 ft, with good results,,, if the crosshair found hair, I'd squeeze, and usually connect with the critter!;)
 
When you go squirrel hunting would you bring something like a 20 gauge shotgun for back up? You'll have a greatly increased probability of bringing home some supper that way. But seriously I'd like to hear how your hunt went. I missed a brief open season last June here in Virginia but sooner or later I want to bag me some tree rats. I've got a Savage Model 64 and am not at all happy with the $10.00 scope it came with.
 
I sight my squirrel rifles at 25 yards. Still good for head shots out to 50, and in to 10. I don't take many shots over 25-30 yards, little buggers wont hold still long enough.
 
If you sight in a .22 at 25 yards, it will likely be close to zero at about 50 yards also. Likewise, if you sight in at 50 yards, it will be very close to zero at 25 yards. The parabolic path of the bullet intersects the scope's line of sight going up and then again going back down.
 
bullet rise

Ok great your answers helped alot it sounds like im good to go with it sighted at 50 yards. One thing im trying to understand is does the bullet actually risea little from the muzzle height, then come down to zero then drop lower and lower?
 
Actually, it never rises above the muzzle line, it hits low at extremely close range because the barrel is about 1.5 inches below the scope. The bore axis and the scope axis converge about 15 yards past the muzzle.
 
@B.L.E.

0 yards -1.5 inches
5 yards - 1.0 inches
10 yards -0.5 inches
15 yards -0.2 inches
20 yards +0.1 inches
25yards +0.3 inches
30 yards +0.4 inches
35 yards +0.4 inches
40 yards +0.4 inches
45 yards +0.2 inches
50 yards zero
55 yards -0.3 inches
60 yards -0.8 inches
Click to expand...

I don't think this can be achieved. A 50 yard zero with 22LR will pass the line of sight for the first time at 50 yards. If you have a rifle/round shooting to the point of aim @ 50 yards it will have a MRT of about +1.5 at 75 yards putting MPBR at around 120 yards... that's a bit far for that cartridge (MPBR is about 90 yards).
-SS-
 
"I don't think this can be achieved. A 50 yard zero with 22LR will pass the line of sight for the first time at 50 yards." Sweet Shooter.


This would be the same thing as having zeroed the rifle, with the exact same set of variables, at 18 yards instead. The difference would be the POI would be 0.01 inches lower at 50 yards. Same result and the minimal difference is not worth considering. ;)
 
@Slugthrower
This would be the same thing as having zeroed the rifle, with the exact same set of variables, at 18 yards instead...
Click to expand...
Not so. You are describing a vector principal, when we need compounding-scalar figures. I will bet a real 5 bob note that with a #1 zero of 18 yards, a 22LR projectile will not cross line of sight again (#2 zero) until past 100 yards. MRT will be about 60 yards, putting the round at least three inches high @ your desired 50 yard zero... and worth considering. If for no other reason that would suggest an unacceptable MPBR of about 150 yards— it would be about 20 inches low—MPBR must have a MRT of plus or minus 3 inches for a small game cartridge like 22LRhttp://www.chuckhawks.com/rifle_trajectory_table.htm.

I reckon a 22 Short might do what you're suggesting, but a 22LR is too flat to conform to a curve/trajectory represented by those numbers listed by B.L.E.

-SS-
 
The Science of Squirrel Shooting

I gotta let my ole lady see this thread - its PROOF that smart people hunt squirrel too! :D
 
My squirrel rifle is zeroed at 25 yards, which works the best for me.

A great way to practice judging distances and hitting headshots, is to shoot at golfballs.:cool:
 
Sweet Shooter quoted BLE and said:
B.L.E.


0 yards -1.5 inches
5 yards - 1.0 inches
10 yards -0.5 inches
15 yards -0.2 inches
20 yards +0.1 inches
25yards +0.3 inches
30 yards +0.4 inches
35 yards +0.4 inches
40 yards +0.4 inches
45 yards +0.2 inches
50 yards zero
55 yards -0.3 inches
60 yards -0.8 inches
Click to expand...

I don't think this can be achieved. A 50 yard zero with 22LR will pass the line of sight for the first time at 50 yards. If you have a rifle/round shooting to the point of aim @ 50 yards it will have a MRT of about +1.5 at 75 yards putting MPBR at around 120 yards... that's a bit far for that cartridge (MPBR is about 90 yards).
-SS-
Click to expand...

I don't understand SS?

My 22LR does shoot very close to BLE's table.
At 25yds its dead on,
at 40 yards it's 1/2" high,
Its back on at 50 yds and
1" low at 60yds.
 
WOW! Has my mileage varied... I bought a brand new Browning T-Bolt .22 a month or so ago. Sighted it with a 2x7 power scope at 25 yards. Went to a precision .22 target shoot a week later. You don't take hunting grade equipment to a precision shoot I learned. Anyway, I was shooting way high (about 4 inches) and hitting the target above the one I was aiming at. I myself find it very odd, a 4" change in just 25 yards. Also found that the expensive precision target ammo makes a big difference compared to the 3 dollar a box stuff. BTW. That Browning T-Bolt is the worst .22 I've ever owned. Two out of 10 rounds does not want to feed and either jams or bends the bullet at the casing. Not to mention it's barely hunting grade accurate.
 
@RaySendero I think I have this all wrong. I just got home and checked with a couple of ballistics apps to work it out, and they all agree with those numbers. It doesn't appear right though... I don't shoot 22 very much and maybe I'm being influenced/confused by the high power cartridges.

So is it right that the first point the projectile crosses the line of sight, with 22LR can't be stretched out to 50 yards? That sounds disappointing to me.

But it appears I'm wrong. Sorry guys.

-SS-
 
I must be strange, my 10/22 is setup with a 3x9 for 100 yards. One mil-dot adjustment for 50 yards and for 25 yards I use a Beretta Neos. No sense in putting the barrel of a rifle in their ears and pulling the trigger (not sporting).

Jim
 
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