Calculators
PROApp featureProjectile Quality QBC Calculator
Evaluate projectile samples by weight, diameter, shape, finish, and visual inspection in a guided QBC workflow.
This page explains a feature of the SC Ballistics app for Android and iOS. The calculation runs in the app, not in the browser.
Access in the app: Available to PRO subscribers.
Result in the app
- 01Average weight and diameter
- 02Standard deviations and shape factor
- 03QBC score and sample classification
Overview
What it does
Evaluate projectile samples by weight, diameter, shape, finish, and visual inspection in a guided QBC workflow.
This guide covers the Projectile Quality QBC Calculator workflow in SC Ballistics, including required values, units, results, and the actions available after calculation.
Tool workflow
Inputs and results
What you enter
- Manufacturer, caliber, shape, and finish
- Target weight and visual rating
- Weight and diameter for 3 to 50 samples
What the app returns
- Average weight and diameter
- Standard deviations and shape factor
- QBC score and sample classification
Tutorial in the app
How to use it in SC Ballistics
Example: a lot of Sierra 168 gr boat-tail bullets, .308 caliber, checked with three samples.
01
Open the tool
In the app, open the Projectile Quality Coefficient (PRO). The screen starts empty, ready for your data.
02
Bullet data
Manufacturer, stated weight (168 gr), shape, nominal caliber (the diameter fills in) and finish.
03
Visual rating
Rate the lot’s overall finish from 1 to 5.
04
Number of samples
Pick 3 to 50 samples. Each one asks for weight and diameter.
05
Weigh and measure each sample
Use a scale and a micrometer. Here: 168, 167.9 and 168.3 gr, at 0.308 to 0.3085 in.
06
Lot result
Tap Calculate BQC: averages, deviations, shape factor and the lot rating (Excellent here).
Before you finish
Good practices
- Check measurement units and source data before calculating.
- Follow range safety procedures and verify technical data with responsible manufacturers.
SC Ballistics is a support tool. Check all inputs, follow range safety procedures, and validate technical information with responsible sources and manufacturers.
Continue in the catalog
Related tools
Use it in the app
Take the tool to the range.
Download SC Ballistics for Android or iOS and follow this tutorial inside the app.