My current situation is I’m shooting 77TMK’s in my 223. I used a cheap chrono to get an average velocity and plugged it in to StrelokPro. The dope it gave me was 0.2 mil too high compared to my actual 550yd holdover. I assume since my chrono is cheap, I should true my velocity to get it to match up? I used the BC pre loaded in the StrelokPro app for the 77TMK (0.202) which I assume is the correct BC to use.
- Thread starter bmicek
- Start date
Double check that all your rifle data is accurate. Scope height, twist, enviromentals ect then I usually just use the bc truing function on strelok pro out just before if goes transonic after I get a velocity from my chrono. The chrono you used would have to be around 50-75fps off to account for .2 according to my strelok app.
I have heard of people truing velocity at around 400-500 yards then truing bc before transonic but never tried it myself.
I have heard of people truing velocity at around 400-500 yards then truing bc before transonic but never tried it myself.
Thanks. Sierra lists G1 BC’s for varying velocities. Think it’s better to enter all those in, or use a single G7 BC?
Do not overthink it, everything matters a little bit, velocity, temp, altitude, humidity, how long the cartridge sits in a hot chamber before you fire, even how the ammo has been stored and for how long.
But get close and then get experience is the best way to get good. Apps are guides, make a dope card from the real world.
But get close and then get experience is the best way to get good. Apps are guides, make a dope card from the real world.
I only tru my velocities. I’ve never messed with the BC’s. 550 yards will be close to the distance you need to tru but 800-1000 is better. But to answer your question, yes you need to tru your numbers to match your actual dope.
Would you use G1 or G7 BC’s? There’s a G7 BC listed but Sierra also lists velocity ranges for a given G1 BC. Not sure which would be more accurate.
First, double-check and verify what scope height you've entered into Strelok, make sure it's correct (use calipers or a ruler, vent hole to the middle of the rings usually works, don't just eyeball it).
Regardless of what your chrono said, true up your MV to what you're printing at 500 yards. You can use whatever BC is listed by the manufacturer, as long as it's in the ballpark you'll be good as long as your MV is correct.
If you've got 700-800 yards to work with, you can true up your BC out there (again, after your MV is already solid).
Regardless of what your chrono said, true up your MV to what you're printing at 500 yards. You can use whatever BC is listed by the manufacturer, as long as it's in the ballpark you'll be good as long as your MV is correct.
If you've got 700-800 yards to work with, you can true up your BC out there (again, after your MV is already solid).
Use the G7. Like others have said, make sure scope height and barrel twist are correct.
Good info, thanks. I have 550 at my local range and 0-900 in a pasture by my house. I’ll focus more on truing my velocity as that’s what I’m least confident in being I have an older chrono.
IME use the one listed by the bullet maker, G7 is usually better than G1, sometimes you need to check their math or convert it to see if one works better than the other in Strelok with this: https://www.jbmballistics.com/cgi-bin/jbmgf-5.1.cgi
It's funny, at one point I owned a Labradar, Magnetospeed, and a caveman optical (ProChrono)... I only kept the ProChrono, and honestly, I'm not sure anyone really needs a chrono anymore since the Apps are so good now.
I have a Labradar and still have to tru my velocities.
That’s what I used, a ProChrono haha I figured it was close but not as precise as the others.
Don't sleep on the ProChrono, their bluetooth App is light f'ing years ahead of Labradar's too lol!
Seriously though, the ProChrono is enough chrono unless you're one of the many nerds who cares more about tracking their ES/SD's than learning the wind (there are a lot of them lol).
Labradar's and Magnetospeed's are fine too I guess lol.
I have a Magnetospeed and still have to make adjustments when shooting past 600ish. Your chrono can only measure at the barrel. A lot happens after that. Obviously, your DOPE is more sensitive to inputs the farther out you go. Adjust for those.
In @koshkin 's video about the PLXc he talked about ensuring a good density altitude number is input for your environmentals to improve Strelok's performance. I've never had good luck with Strelok but don't think I've tried that hard to get it to work either. DA will be the first thing I try next time out.
I've had poor luck with Density Altitude in Strelok Pro in the south east (works great with a Kestrel though). YMMV.
On the subject, IMO one of the coolest things about Strelok Pro is how easy and often one can update their weather. I update my weather pretty much everytime I look at it, right off the bat when I first open it, and then several times throughout the course of a range day or match. Sometimes though, like at K&M, you have to know where to wonder to get enough cell bars lol.
ETA: Though, the weather update process might be something they could upgrade to a one-click operation since now it's:
weather bar/button on main screen > press globe/metro icon > press use these values > press "save" > back to main screen, press "calculate"
On the subject, IMO one of the coolest things about Strelok Pro is how easy and often one can update their weather. I update my weather pretty much everytime I look at it, right off the bat when I first open it, and then several times throughout the course of a range day or match. Sometimes though, like at K&M, you have to know where to wonder to get enough cell bars lol.
ETA: Though, the weather update process might be something they could upgrade to a one-click operation since now it's:
weather bar/button on main screen > press globe/metro icon > press use these values > press "save" > back to main screen, press "calculate"
Last edited:
