Boresighting a scope - .22lr. BD on a hundred?

[Jayjay1]

Hey guys,
when I´m boresighting my scope at 100yds., what means that my boreline and my sightline meet at 100yds., how much will I have to elevate my scope with the .22lr. approxametly?

Sorry that I don´t know the velocity, so I´m just asking for a guess with a average speed (22" barrel).

 

[Near miss]

My Kestrel shows 19.11" drop at 100yds.

18.25moa or 5.3mil to get the POA to POI.

 

[Jayjay1]

My Kestrel shows 19.11" drop at 100yds.

18.25moa or 5.3mil to get the POA to POI.

How did you get BC data for the Kestrel?!

I have one on myself, but have no 22lr BC-data, or do I?

 

[1911JMB]

it is roughly 6" in most cases but bore sighting is only to get on paper best done at 25 yards or so then work a real dope card from there.

 

[Near miss]

How did you get BC data for the Kestrel?!

I have one on myself, but have no 22lr BC-data, or do I?

Kestrel 5700 AB. Which model yours is?

I assumed in my reply that you do not have range closer than 100yds.

I wonder why it gives such a large drop value.

 

[Jayjay1]

Kestrel 5700 AB. Which model yours is?

I assumed in my reply that you do not have range closer than 100yds.

I wonder why it gives such a large drop value.

5700 AB, the same.

Yes, you are correct, mostly close to only shooting on a 100.

What I know from earlier times (another rifle), is that I had to correct elevation from 50 to 100 at about 10" up, so those numbers might adequate.

 

[Near miss]

5700 AB, the same.

Yes, you are correct, mostly close to only shooting on a 100.

What I know from earlier times (another rifle), is that I had to correct elevation from 50 to 100 at about 10" up, so those numbers might adequate.

Oh, good to hear.

Just go check the AB bullet library in the phone app under .224 caliber. I use the cdm but G1 goes quite well with 22LR for quite long distance, if I remember correctly, roughly 0.1mil off from cdm until it spreads a bit after 300ish.

 

[Jayjay1]

Oh, good to hear.

Just go check the AB bullet library in the phone app under .224 caliber. I use the cdm but G1 goes quite well with 22LR for quite long distance, if I remember correctly, roughly 0.1mil off from cdm until it spreads a bit after 300ish.

Oh my dear, I had no glue, thanks a lot.

 

[Fasteddie01]

I read lots of 'old' threads and last week I found one from July-29-2019 on this topic of .22 LR BC - 308ftWIN found many BCs. I didn't save the link, just the data, but you can look it up. Kestrel updated data back then for some .22, have you run updates?

 

[Mordamer]

If you bore sight at 100 yards you'll need to dial up about 2.5 mils on your scope to be zeroed at a reasonable distance. I recommend zeroing at 35 yards because all elevation adjustments will be up from a 35 yard zero. Your velocity will be about 1,070 fps if using target ammo and your BC will usually be about .145 G1.

These numbers will get you close enough to start. Get a perfect zero at 35 yards and then use the above numbers to get you close with your kestrel at 100 yards. True up your velocity in the kestrel to make the kestrel match your real drop at 100 yards. This will get you very close with the kestrel from 0 to 200 yards.

 

[Near miss]

If you bore sight at 100 yards you'll need to dial up about 2.5 mils on your scope to be zeroed at a reasonable distance. I recommend zeroing at 35 yards because all elevation adjustments will be up from a 35 yard zero. Your velocity will be about 1,070 fps if using target ammo and your BC will usually be about .145 G1.

These numbers will get you close enough to start. Get a perfect zero at 35 yards and then use the above numbers to get you close with your kestrel at 100 yards. True up your velocity in the kestrel to make the kestrel match your real drop at 100 yards. This will get you very close with the kestrel from 0 to 200 yards.

Is not modifying BC preferred near subsonic flight? I have chrono so I cannot say which is better.

I'd suggest first zeroing, then shoot for dope. Mark distances and elevation used on paper, then at home check the center of group from the targets and tweak that elevation.

After you have the dope for different distances (out as far as possible), test which BC value gives you the closest results to real life and use that.

Also, to get first rounds closer to target put temperature table on and use 1.5m/s per Celsius to keep up with changes in temperature.

 

[Dthomas3523]

Is not modifying BC preferred near subsonic flight? I have chrono so I cannot say which is better.

I'd suggest first zeroing, then shoot for dope. Mark distances and elevation used on paper, then at home check the center of group from the targets and tweak that elevation.

After you have the dope for different distances (out as far as possible), test which BC value gives you the closest results to real life and use that.

Also, to get first rounds closer to target put temperature table on and use 1.5m/s per Celsius to keep up with changes in temperature.

You’re already subsonic when bullet leave barrel.

BC matters very little with .22 compared to velocity.

 

[308pirate]

Why do people make this so much more difficult than it needs to be?

Boresight the scope in at 25 yards, get on paper at same, then zero it wherever you want.

Trying to start this process at 100 yards/meters with a 22lr is stupid.

 

[Jayjay1]

Well, then stupid is standard at our range.
Rifles can only be shot at a 100.

But interesting point with going subsonic.
I´m thinking it would be clever to shoot subsonic, because you don´t have to go backwards through the speed of sound.

 

[308pirate]

Well, then stupid is standard at our range.
Rifles can only be shot at a 100.

You're right. It's stupid to require rimfire rifles to be shot at 100 meters when everyone knows the standard distance for ISSF smallbore rifle is 50.

I'd find someplace else to go.

 

[Dthomas3523]

Well, then stupid is standard at our range.
Rifles can only be shot at a 100.

But interesting point with going subsonic.
I´m thinking it would be clever to shoot subsonic, because you don´t have to go backwards through the speed of sound.

Most Rimfire ammo us subsonic. “Standard velocity” is subsonic.

 

[Near miss]

You’re already subsonic when bullet leave barrel.

BC matters very little with .22 compared to velocity.

Thanks. Was not really sure, since I always use the correct MV - so I've never had an issue with MV not matching.

 

[Dthomas3523]

Thanks. Was not really sure, since I always use the correct MV - so I've never had an issue with MV not matching.

Doesn’t matter if your MV matches your actual chrono or not. Just that your dope matches.

This isn’t a perfect science yet (if it was, all software would use the same calculations and give you the exact same answers if you input the exact same information). Too many get hung up with the “my MV is known, I should never change it” when they don’t know what the software is or isn’t doing correctly.

 

[Jayjay1]

Well, this is a training rifle, and I very much enjoy shooting it on a 100.

"ISSF smallbore rifle", I don´t care.

So, I´m stupid and having fun.

 

[grauhanen]

Hey guys,
when I´m boresighting my scope at 100yds., what means that my boreline and my sightline meet at 100yds., how much will I have to elevate my scope with the .22lr. approxametly?

Sorry that I don´t know the velocity, so I´m just asking for a guess with a average speed (22" barrel).

You can boresight at 100 yards and then increase your elevation by how much the bullet is expected to drop at that distance.

Here's a ballistics chart that compares two different standard velocity rounds, Lapua Center X and CCI SV. They are almost identical in nominal MV, 1073 fps and 1070 fps. But those differences are relatively unimportant because no one knows what the actual MV of any given round will be, and the MV will vary from one barrel to the next. The ballistic coefficient (BC) of the two are different, the CX at .161 and CCI at .120 (according to the ballistics calculator used). That makes a bit of a difference at 100 yards.



If you increase the elevation by roughly 17" you will be close. The thing to remember is that no ballistics calculator can make the exact determination for a couple of reasons. First, MV will vary from one round to the next. The MV printed on the ammo box is an average in the manufacturer's test barrels, not a written guarantee of what it will be in practice. Second, MV in one rifle is not necessarily the same from barrel to barrel.