FAQ
Questions, answered.
What is free, how Pro and the trial work, how SureHold learns your rifle, and how far to trust the numbers.
The basics
- What is SureHold Ballistics?
- A ballistic calculator and range log for rifle shooters. The calculators give you drop, wind and velocity for your bullet and conditions. The range log lets you record what you actually shot, and SureHold uses those shots to calibrate your real muzzle velocity, ballistic coefficient and wind behavior, so it learns your rifle.
- Is it free?
- The calculators are free and need no account. A free account keeps 1 rifle, 1 saved load and 3 logged shots so you can try the range log. Pro costs $5.99 a month or $49.99 a year, with a 14-day free trial, and adds calibration from your own shots, unlimited shots and loads, and up to 10 rifles.
- Does SureHold suggest loads or powder charges?
- No, and it never will. You can log the loads you already shoot, and you should follow published load data and safe practices for everything else.
- Does it work with no signal?
- Yes. Once the site has loaded, or after you add it to your phone's home screen, the calculators and the range log keep working with no signal, and your range log syncs when you are back online.
- How do I put it on my home screen?
- On an iPhone, open sureholdballistics.com in Safari, tap the Share button, then Add to Home Screen. On Android, open it in Chrome, tap the menu, then Install app (or Add to Home screen). It then opens like an app.
- Does it use imperial or metric?
- Both. Each rifle is either imperial or metric, chosen when you create it. Rifle and ammo specs are always typed in inches, grains and feet per second, and shown back in the rifle's own system.
Accounts and billing
- How does the free trial work?
- Pro starts with a 14-day free trial. You enter a card on Stripe's secure page, and you are not charged until the trial ends. Cancel any time before then and you pay nothing. The trial is one per person.
- How do I cancel?
- Open your account page and choose Manage billing. It opens Stripe's customer portal, where you can cancel, change your card, switch between monthly and yearly, and download receipts. If you cancel, Pro stays on until the end of the period you already paid for.
- What happens to my data if I cancel?
- Your rifles, loads, range days and any calibration you saved stay. The free plan's limits then apply to adding more.
- Who can see my data?
- Your rifles and range days belong to you and are visible only to your account. See the Privacy Policy for the details.
- Can I download or delete my data?
- Yes, both. Your account page has Download my data, which gives you everything you stored as one file, and Delete my account, which removes your account and everything in it (and cancels any subscription first).
- Who runs SureHold?
- SureHold Ballistics is operated by Brown Trout Holdings LLC, a Wyoming limited liability company. Use the contact page for questions about your account, billing or privacy.
Accuracy and calibration
- How accurate is it?
- The solver was checked against an independent one and agrees on drop to within about 0.1 percent. But a calculator is only as good as its inputs. Standard drag tables describe an average bullet, and the velocity on a box was measured in a different barrel. Treat the numbers as estimates and confirm them at the range.
- What does calibration do?
- You log what you dialed or held and where the shots landed, along with the conditions. SureHold fits your real muzzle velocity, ballistic coefficient, temperature sensitivity and zero offset to those shots, and can fit a wind scale and horizontal zero from your windage. It also checks itself by leaving one range day out and seeing how well the fit predicts it.
- Why does my real drop not match the calculator?
- The usual causes, roughly in order: muzzle velocity (box versus your rifle), the ballistic coefficient and drag model, a wrong sight height or zero distance, and pressure or temperature entered incorrectly. Logging real shots lets you fit the numbers instead of guessing.
About the calculators
- Do I need a chronograph?
- It helps a lot. Muzzle velocity has the biggest effect on drop, and the number on the box came from a different barrel. Without one, enter the box number, then check your drop at the range and adjust.
- What twist rate do I need?
- Enter your bullet's weight, diameter and length from the maker's page (measure the length with calipers if it is not listed) and your velocity. The calculator returns the slowest twist for Sg 1.3 and 1.5. Heavier and longer bullets need faster twists.
- Is a faster twist always better?
- Once Sg has a comfortable margin, extra spin adds no stability benefit and slightly increases spin drift at long range, so there is nothing to gain from going faster than you need.
- Why does temperature change stability?
- Cold air is denser, which increases the overturning force the spin has to resist, so Sg falls. Higher pressure does the same. Hot air and high altitude raise Sg.
- What if my Sg is above 3?
- It is still stable, but models that build on it, such as spin drift, are less certain at very high values, and the calculators flag that.
- Which pressure should I enter?
- Use station pressure if you have a meter that reads it. If you only have a weather report or phone value, choose sea-level pressure and enter your altitude so the calculator can convert it.
- Does density altitude change where my bullet lands?
- Yes, mostly at longer distances, where thinner air means less drop and less wind drift. Enter your conditions in the trajectory calculator to see the effect on your own load.
- Does humidity really matter?
- Only a little. Temperature and pressure drive density; humidity is a small correction that is most noticeable on hot days.
- Which is better, MOA or mil?
- Neither is more accurate. Choose the one that matches your scope's turrets and reticle so you dial and hold in the same unit. Mils work neatly with metric distances.
- Why do my clicks not land where the calculator predicts?
- Common causes are a different click value than you entered, a scope built on shooter's MOA, turret tracking error and a wrong distance. A tall-target test shows your real click value.
- Does the calculator work in metric?
- Yes. Distances, corrections and units can be entered in imperial or metric.
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