Trueing 22LR BC

[unoigo]

Working on 22lr dope for a PRS match coming up in 2 weeks and I’m stuck.

50 yd zero and dial to 100 perfectly, dial to 200 and I’m 6” low. Adjust BC, get on target and all good. Next go out to 300, I’m roughly 6” high. So I take BC back down to where it was previously and I’m 3” high. Go back to 200 and 6” low again as presumed.

I’m new to 22lr long distance precision shooting so bare with me but can’t wrap my head around a 22 being low at 200 then high at 300. Am I missing something?

Vudoo 18” kukri
Midas + 1050 FPS average
50 degrees, minimal wind
.132 BC

 

[phlegethon]

Are you measuring height over bore? What ballistic calculator are you using? Did you try adjusting MV instead?

 

[unoigo]

Yes on height over bore. Using Kestrel 5700 non elite. Did not adj MV as I used labradar for the avg. My next course of action is use MV method and/ or upgrade to 5700 elite for the additional functionality.

 

[JustSendit]

How certain are you of these ranges? Sounds silly but even 5 meters matters with 22 at 300.

 

[unoigo]

How certain are you of these ranges? Sounds silly but even 5 meters matters with 22 at 300.

Ahhhh. Good point. I’m not. Will check. Thanks.

 

[Mordamer]

Set your BC to .15 and true your dope by only adjusting velocity. I have found this to be way more practical than messing with BC.

BC on a .22 makes very little difference, but velocity makes a huge difference. Your labradar is fooling you I suspect.

The other rookie mistake is to not have a perfect zero. Burn a bunch of ammo into one group and use that to adjust your zero.

Once your dope is perfect for everything from 50 to 200 then make tiny adjustments to BC to true up at 300+.

 

[parshal]

Mr. Zick's link got mine spot on.

 

[JustSendit]

Mr. Zick's link got mine spot on.

The weaponized math holds gave you accurate data and the AB software did not? That’s great you have good dope but I am curious why AB failed. Myself and many others had great luck using the SK Match Custom Drag Model, and a generic MV. Consistent hits at 400-450m, while still maintaining good DOPE at less distances.

There is something going on in the software somewhere (an input or glitch) that’s throwing a wrench in the dope.

 

[parshal]

My apologies. When I glanced at the link I thought it was this one where I used DSF on the Kestrel and Tactix. Additionally, on the Tactix, you can add multiple distances which I did at 70, 80, 90 and 100.

22LR using DSF

 

[bribassguy]

StackPath

Did you try this? MV cal at 200 and DSF at 300.

 

[unoigo]

Not yet. I have a standard 5700 and just bought the elite version. Hope to have it in hand by week’s end and if the weather holds up will test it this weekend.

 

[Geno C.]

Download the Lapua ballistic app. Choose Midas+ as your ammo. Enter your speed. Capture the environmentally. Done. Sounds simple and it works. No messing around. If your impacts are off from this app, you have an equipment problem

 

[goneballistic]

Mr. Zick's link got mine spot on.

What is mr zinks link? I'm not seeing a link

 

[parshal]

I put it in my last post above.

 

[goneballistic]

I put it in my last post above.

Thank you.

I can't get it to open, not sure if it's me or the link

 

[PinesAndProjectiles]

Thank you.

I can't get it to open, not sure if it's me or the link

It's a link to a PDF file. I attached it here.

 

[goneballistic]

It's a link to a PDF file. I attached it here.

Super helpful! Thank you!