22 DOPE issues

[Jonathan DeBoer]

I have been struggling to get an accurate DOPE card. I have found that SK Pistol Match Special and Eley Team shoot amazing (sub moa) out to 250 in calm winds. I have shot at 100 yards using my 50-yard zero to try and true my velocity. I found it drops 18 1/2 cm or 7.28 inches on average. I am unsure of what ballistic coefficient to use in my calculator. I have looked around and found people using .110 to .175 for their BC. I do not have access to a chronograph right now, although I have considered getting one. I have used multiple calculators to get consistently inconsist resuls: GeoBalistics, Hornady, Balistics AE.

 

[1911JMB]

You can use AB and true it every 50 yards from close to far. There are also actual drop curves for certain loads but you really need to know the actual MV.

 

[J_D]

Assuming you are using a phone app, you need to invest in a MagnetoSpeed, even the Sporter will work, although I like my V3. You need to have that starting point of MV from your specific barrel. With respect to all data collection, you get what you put in. Garbage in = Garbage out.

More info here......https://www.snipershide.com/shooting/threads/what-methods-do-you-use-for-truing-22lr-dope.7134381/

 

[littlepod]

Just FYI, with subsonic bullets, BC is a variable of velocity, which means also a variable in distance. The published BC on the ammo is the BC at 50 yards ~ .172 for Lapua ammo.

By the time you hit 300 yards, you're at a BC of .11.

So that means the curve needs to change across the distance, and a static BC isn't going to work.

Kestrel Elite / AB Elite allow you to add drop scale factor and it tries to map this across the distance.

Also AB Elite has custom doppler curves for some ammo that also does this BC mapping.

I think Strelok Pro has some custom curves as well and also allows variable BC.

 

[Cowpokey]

Assuming you are using a phone app, you need to invest in a MagnetoSpeed, even the Sporter will work, although I like my V3. You need to have that starting point of MV from your specific barrel. With respect to all data collection, you get what you put in. Garbage in = Garbage out.

More info here......https://www.snipershide.com/shooting/threads/what-methods-do-you-use-for-truing-22lr-dope.7134381/

MagnetoSpeed's website says the Sporter model is for centerfire rifles only. My V3 works great, after adjusting the sensitivity for rimfire...pretty sure I set mine to "6", been a while.

 

[Defender32]

This is what I use most of the time. I do have a Magneto Speed V3 as well. The Velocity difference in the 2 is null. You just need a good starting point. The Sporter will work on RF as well a few people at the club have them.


** This was a test done at out Gun Club by @Chopping Broccoli **

FX Pocket Chronograph v2 - Utah Airguns

The revolutionary pocket radar chronograph just got upgraded!

utahairguns.com

 

[DownhillFromHere]

I think Strelok Pro has some custom curves as well and also allows variable BC.

Yes, do this:

1. Tap the cartridge screen's Ballistic Coefficient field
2. At bottom right, tap the Lapua button
3. Select "22LR-XACT-Midas-CenterX- Lapua 2,59g_Radar.drg" entry and tap "Done"
4. The selected drag curve shows as ".22LR Lapua Center Xc2.59g" and should be selected. If not, tap to select it.
5. Tap "Done" to apply it to your cartridge entry.
6. Back on the cartridge screen, the curve shows in the BC field.

You'll still have to tinker with truing velocity - you can alter range/BC entries in the curve itself if you want to. This curve works for me out to 400+ yards.

Unless something has changed since I had my Vudoo lot-tested at Capstone/Lapua's Mesa facility, all flavors of Lapua and SK ammo except Polar Biathlon Extreme use the same lube on the same bullet. So this curve should work for all of them (and Biathlon has its own curve).

 

[Badjujuu]

MagnetoSpeed's website says the Sporter model is for centerfire rifles only. My V3 works great, after adjusting the sensitivity for rimfire...pretty sure I set mine to "6", been a while.

6 is what I run as well

 

[DFOOSKING]

I have been struggling to get an accurate DOPE card. I have found that SK Pistol Match Special and Eley Team shoot amazing (sub moa) out to 250 in calm winds. I have shot at 100 yards using my 50-yard zero to try and true my velocity. I found it drops 18 1/2 cm or 7.28 inches on average. I am unsure of what ballistic coefficient to use in my calculator. I have looked around and found people using .110 to .175 for their BC. I do not have access to a chronograph right now, although I have considered getting one. I have used multiple calculators to get consistently inconsist resuls: GeoBalistics, Hornady, Balistics AE.

Better hurry. You got a month to get your dope squared away for the rimfire matches in SD will be running again.

 

[chanrobi]

You don't need a chrono, simply true

Don't care what the MV is, you just need the holds

Todd Hodnett - The Long-Range Cowboy

We sit down one of the best long-range shooting instructors in the world and founder of Accuracy 1st, Todd Hodnett.

www.recoilweb.com

 

[J_D]

You don't need a chrono, simply true

Don't care what the MV is, you just need the holds

Todd Hodnett - The Long-Range Cowboy

We sit down one of the best long-range shooting instructors in the world and founder of Accuracy 1st, Todd Hodnett.

www.recoilweb.com

Good way to waste a lot of ammo throwing rds downrange to get a sold waterline. If you have an actual MV to input into Strelock or a Kestrel, you have a decent starting point to get early impacts and then you true from there.

How much ammo would you burn using multiple lots? SK, Lapua, and Eley vary quite a bit. A chrono greatly simplifies the starting points at various distances, then you can true.

 

[chanrobi]

Good way to waste a lot of ammo throwing rds downrange to get a sold waterline. If you have an actual MV to input into Strelock or a Kestrel, you have a decent starting point to get early impacts and then you true from there.

How much ammo would you burn using multiple lots? SK, Lapua, and Eley vary quite a bit. A chrono greatly simplifies the starting points at various distances, then you can true.

Didn't bother reading the link I see

"But for the guys in the field, they don't have chronographs. One of the primary reasons we teach the way we teach is because in the field, I can take three or four rounds of ammo and gather the new M.V. by shooting it on a rock at the distance of transonic and have a perfect algorithm. When truing, you true at transonic because you measure long to predict short in any mathematical equation for accuracy."

 

[J_D]

Didn't bother reading the link I see

"But for the guys in the field, they don't have chronographs. One of the primary reasons we teach the way we teach is because in the field, I can take three or four rounds of ammo and gather the new M.V. by shooting it on a rock at the distance of transonic and have a perfect algorithm. When truing, you true at transonic because you measure long to predict short in any mathematical equation for accuracy."

I read the link........did you read the OP's question? Also how much of that relates to rimfire with a G1 BC?

OP you should be roughly 0.122 for SK, 0.128 for Eley, but a chrono will help you greatly. Every barrel and rifle is different.

 

[chanrobi]

I read the link........did you read the OP's question? Also how much of that relates to rimfire with a G1 BC?

OP you should be roughly 0.122 for SK, 0.128 for Eley, but a chrono will help you greatly. Every barrel and rifle is different.

"The beauty of truing is, even if your ballistic coefficient (B.C.) is off, your algorithm tracks in the opposite direction. We're looking for the time of flight to target. From that we equate backward to the muzzle velocity (M.V.) that gives us a perfect algorithm. I could care less whether my M.V. is tracking perfectly with the chronograph; all I care about is that my hold is perfect for every target."

"BCs are suggested by the manufacturer, and we know a lot of them are off. Truing is the only way that you'll ever be able to gather a correct algorithm if your B.C. isn't perfect. If we knew the perfect B.C. and the perfect muzzle velocity, there's no need to true."

I mean if you want to keep contradicting yourself and being incorrect, lets go

 

[J_D]

"The beauty of truing is, even if your ballistic coefficient (B.C.) is off, your algorithm tracks in the opposite direction. We're looking for the time of flight to target. From that we equate backward to the muzzle velocity (M.V.) that gives us a perfect algorithm. I could care less whether my M.V. is tracking perfectly with the chronograph; all I care about is that my hold is perfect for every target."

"BCs are suggested by the manufacturer, and we know a lot of them are off. Truing is the only way that you'll ever be able to gather a correct algorithm if your B.C. isn't perfect. If we knew the perfect B.C. and the perfect muzzle velocity, there's no need to true."

I mean if you want to keep contradicting yourself and being incorrect, lets go

I'm not contradicting myself.....I stand by the fact that I use a factory BC from AB, chrono for MV, and then true my kestrel from 200 out. Works perfect for me, and the question was about ballistic calculators and DOPE.

This isn't about how awesome Todd is......there's no doubt he's a smart guy. You didn't write anything......you just regurgitated something you read, and basically stating that everyone here who owns a chrono is less smart than you.......Good for you! You win.