Watch App: TruFlite Ballistics

Good morning 

I have entered my info as accurately as possible.

308 @178 grain. 

Bc of .278. 

However at 300 yard i need 5.5 M0A. 

Tru flight report it at 4.75.... anything else i can do to get a more accurate reading. 

[email protected] 

email sent.

Hi fantastic app. 

Some things I’ve noticed and one thing I’d like. 

Love the app would like instead of  auto filling in if like to input actual dope I’ve recorded 

I’ve put in all my info FPS measured via chrono and BC from Hornady. Your app said 15plus moa when I know it’s exactly 12 I’ve played with speed an elevation adjustment as low as I can go which is .900 and it’s closer 12.75 instead of 12 so not too bad but just as an aid to get on paper the option to type in my dope would be great. Thanks for the app I appreciate all you guys who take time and make these things 

Can you provide some more info such as BC, muzzle velocity, range, current Barometric Pressure.  TruFlite has been compared to many other, current, modern ballistic calculators and generates very similar results.   The difference you are seeing is quite large, something is off.  You should be able to generate a accurate trajectory to match your field results.

thanks

jeff

Thanks Jeff. I think I’m going to start from scratch zero rifle at 100 confirm good etc. It’s too far out something gone wrong somewhere probably just me.  Projectile is 6.5creed 147gr. With superformance average FPS was around 2700 measured through chrono. Range was 600meters. Don’t know pressure of last shoot. 

Hi Jackson,

did you had a chance to think about the zero offset? Would be quite handy to have it. For example the app Strelok is offering it and I use it now with all my scopes.

>Clicks - Can now select Clicks for Elevation and Windage Units. If selected then asked to provide click precision; e.g. 1/4 >MOA or 1/10 Mils

Could I use also 1/20 Mils? My scope is using 0,05mils per click

Jackson, any chance that the instinct tactical will support this app in the near future?

Unfortunately the Instinct devices do not allow installing applications from the Connect IQ store.   This is probably the most common question i get recently, would love to offer it, but can't do to this limitation.

Any more advanced versions which would take spin drift or coriolis into effect?? 

In the email notice you asked more than what is showing on the forum thread, so I will repost it here: 

I am having problems.  I am shooting .338 LM  300gr sierra match king bullets bc=.768.  I have my dope cards and calc tables that i have been successfully using to shoot out to 1760 yds ( 1 mile)  .  When i set it up with all of my proven data....i get calculations that are waaay too low.  When i change the bullet profile from G7 ( which smk bullets are) to the G1 option....i am within 1 MOA of where i should be, but thats the wrong profile.   Any ideas whats going on?   The app does not ask for my bullet weight although maybe it doesn't need it with the BC.

Short Answer:   Use a good known G7 ICAO BC:  0.380 G7 BC (ICAO) for Sierra 338 300gr MK

Long Answer:  Two Things:

1. BC is relative to a particular drag curve (e.g. G1, G7, etc).  The BC you have is a G1 BC, therefore you need to tell TruFlite that.  If you tell it that it is a G7 BC then that is one heck of a great G7 BC (hence the low correction).

2.  Bullet companies publish BCs based against one of two environmental standards; ASM (Army Standard Metro) or ICAO (Internationcal Civil Aviation Org.)   TruFlite assumes the BC is relative to ICAO, as it is the more modern standard.   Sierra still publishes against ASM.  To convert, lower the 0.768 by 1.8% = 0.754.  Hence probably while you are still a little off.

You are correct your bullet better matches a G7 profile.  Therefore you should use a G7 BC.   Using a G1 BC does not match how that bullet will shed velocity properly.  Will it be close, sure, but G7 will be better, especially at range.  You will notice Sierra publishes multiple G1 BCs for that bullet.   Because G1 doesn't fit as well.

Jeff