# Parameter Validation Reference

## Overview

This document provides comprehensive validation ranges, typical values, and quality assurance guidelines for ballistic simulation parameters. Use this reference to verify that your configuration values are physically realistic and within expected bounds.

## Bullet Properties Validation

### Physical Dimensions

#### Grain Weight Validation
| Caliber Category | Typical Range (grains) | Examples |
|------------------|------------------------|----------|
| Rimfire | 20-60 | .22 LR: 30-40 gr |
| Small Pistol | 60-130 | 9mm: 115-147 gr |
| Large Pistol | 130-300 | .45 ACP: 200-230 gr |
| Small Rifle | 40-90 | .223: 55-77 gr |
| Medium Rifle | 100-200 | .308: 150-180 gr |
| Large Rifle | 200-500 | .338: 250-300 gr |
| Anti-Material | 500-750+ | .50 BMG: 647-750 gr |

**Quality Checks:**
- Weight should correlate with caliber size
- Unusually light bullets (<20 gr) may indicate frangible/training rounds
- Unusually heavy bullets (>300 gr for caliber) may indicate specialty rounds

#### Diameter Validation
| Caliber | Actual Diameter (inches) | Metric Equivalent |
|---------|--------------------------|-------------------|
| .17 | 0.172 | 4.37mm |
| .22 | 0.224 | 5.69mm |
| .24 | 0.243 | 6.17mm |
| .25 | 0.257 | 6.53mm |
| .27 | 0.277 | 7.04mm |
| .28 | 0.284 | 7.21mm |
| .30 | 0.308 | 7.82mm |
| .32 | 0.312 | 7.92mm |
| .35 | 0.358 | 9.09mm |
| .38 | 0.357 | 9.07mm |
| .40 | 0.400 | 10.16mm |
| .44 | 0.429 | 10.90mm |
| .45 | 0.452 | 11.48mm |
| .50 | 0.510 | 12.95mm |

**Quality Checks:**
- Diameter must be positive and reasonable (0.1-0.8 inches typical)
- Should match known caliber specifications
- Metric conversions should be consistent

#### Length-to-Diameter Ratio
| Bullet Type | Typical L/D Ratio | Length Range (inches) |
|-------------|-------------------|----------------------|
| Round Nose | 1.5-2.5 | Short, traditional design |
| Spitzer | 2.5-4.0 | Pointed, aerodynamic |
| Boat Tail | 3.0-4.5 | Long, high BC |
| VLD | 4.0-6.0 | Very Low Drag, match |
| Solid | 2.0-5.0 | Monolithic construction |

**Quality Checks:**
- L/D ratio should be realistic for bullet type
- Very long bullets (L/D > 6) may have stability issues
- Very short bullets (L/D < 1.5) are unusual outside specialty applications

### Ballistic Coefficients

#### G1 Ballistic Coefficient Ranges
| Bullet Shape | BC Range | Description |
|--------------|----------|-------------|
| Round Nose | 0.15-0.25 | Traditional, poor aerodynamics |
| Flat Point | 0.20-0.30 | Lever gun bullets |
| Spitzer | 0.25-0.45 | Standard pointed bullets |
| Boat Tail | 0.35-0.55 | Improved base design |
| Match/VLD | 0.45-0.70+ | Optimized for accuracy |
| Ultra-High BC | 0.70-1.0+ | Specialized long-range |

#### G7 to G1 Conversion
- G7 BC typically 0.5-0.7× the G1 value for modern bullets
- Conversion varies by bullet shape and velocity regime
- G7 more accurate for boat-tail designs

**Quality Checks:**
- BC should correlate with bullet shape and quality
- Extremely high BC (>0.8 G1) requires verification
- G7 values should be lower than corresponding G1 values

### Material Properties

#### Bullet Hardness (BHN)
| Material | Hardness Range | Applications |
|----------|----------------|--------------|
| Pure Lead | 5-8 BHN | Cast bullets, training |
| Wheel Weights | 12-15 BHN | Economy cast bullets |
| Linotype | 22-25 BHN | Hard cast bullets |
| Swaged Lead | 8-12 BHN | Commercial lead bullets |
| Copper Plated | 10-15 BHN | Plated lead core |
| Copper Jacket | 15-25 BHN | FMJ bullets |
| Brass | 60-120 BHN | Solid brass bullets |
| Copper Solid | 35-80 BHN | Monolithic copper |
| Steel Core | 150-300 BHN | AP bullets |
| Tungsten | 300-400 BHN | High-density cores |

**Quality Checks:**
- Hardness should match material type
- Jacket hardness is composite value including core
- Extremely hard bullets (>400 BHN) are specialized

#### Energy and Velocity Thresholds

**Penetration Energy Threshold (ft-lbs)**
| Application | Energy Range | Examples |
|-------------|--------------|----------|
| Small Game | 10-25 | Squirrel, rabbit |
| Varmint | 25-75 | Prairie dog, coyote |
| Deer | 75-150 | White-tail deer |
| Elk | 150-300 | Large game |
| Dangerous Game | 300-500+ | Bear, buffalo |
| Armor Piercing | 500-2000+ | Military applications |

**Expansion Velocity Threshold (fps)**
| Bullet Type | Velocity Range | Notes |
|-------------|----------------|-------|
| Handgun HP | 800-1200 | Lower velocity expansion |
| Rifle HP | 1600-2200 | Standard hunting bullets |
| Premium Hunting | 1400-1800 | Controlled expansion |
| Varmint | 2000-3000 | Rapid expansion |
| Match | N/A | Non-expanding |

**Quality Checks:**
- Energy thresholds should match intended use
- Expansion velocities should be achievable at impact range
- Thresholds should be lower than typical muzzle velocities

## Material Response Validation

### Physical Properties

#### Density Values (g/cm³)
| Material Category | Density Range | Common Materials |
|-------------------|---------------|------------------|
| Woods | 0.3-1.2 | Balsa (0.16), Oak (0.75), Ebony (1.2) |
| Plastics | 0.9-2.0 | PE (0.95), Nylon (1.15), PVC (1.4) |
| Aluminum Alloys | 2.6-2.8 | 1100 (2.71), 6061 (2.70), 7075 (2.81) |
| Concrete | 2.0-2.8 | Normal (2.4), High-strength (2.6) |
| Titanium Alloys | 4.4-4.9 | Ti-6Al-4V (4.43), CP Ti (4.51) |
| Steel | 7.7-8.1 | Mild (7.85), Stainless (8.0) |
| Lead | 11.3-11.4 | Pure lead (11.34) |
| Tungsten | 19.2-19.3 | Pure tungsten (19.25) |

#### Hardness Correlation
**Brinell Hardness (HB)**
| Material | Hardness Range | Strength Correlation |
|----------|----------------|---------------------|
| Aluminum (soft) | 15-30 | Low strength |
| Aluminum (hard) | 60-150 | Heat treated |
| Steel (mild) | 120-200 | Structural steel |
| Steel (medium) | 200-300 | Heat treated |
| Steel (hard) | 300-500 | Tool steel |
| Steel (very hard) | 500-700 | Hardened/tempered |
| Ceramics | 1000-2000+ | Very brittle |

**Quality Checks:**
- Hardness should correlate with tensile strength
- Rule of thumb: BHN ≈ 3.45 × Tensile Strength (ksi)
- Very hard materials often brittle

#### Strength Properties (MPa)

**Tensile Strength Ranges**
| Material Class | Yield Strength | Tensile Strength | Ratio (Yield/Tensile) |
|----------------|----------------|------------------|----------------------|
| Aluminum (soft) | 35-100 | 90-200 | 0.4-0.5 |
| Aluminum (hard) | 200-500 | 300-600 | 0.6-0.8 |
| Steel (mild) | 200-400 | 400-600 | 0.5-0.7 |
| Steel (high strength) | 400-1000 | 600-1200 | 0.7-0.8 |
| Stainless Steel | 200-800 | 500-1000 | 0.4-0.8 |
| Titanium | 200-1000 | 300-1200 | 0.6-0.8 |

**Quality Checks:**
- Yield strength must be ≤ tensile strength
- Typical ratio: yield = 50-80% of tensile
- Higher ratios indicate brittle materials

### Ballistic Properties

#### Ballistic Limit Velocities (fps)
| Material/Thickness | Velocity Range | Projectile Type |
|-------------------|----------------|-----------------|
| Aluminum 0.25" | 800-1500 | Standard ball |
| Steel 0.25" | 1500-2500 | Standard ball |
| Steel 0.5" | 2500-3500 | Standard ball |
| Kevlar vest | 1200-1800 | Handgun bullets |
| Ceramic tile | 2000-3500 | Rifle bullets |
| Glass | 200-800 | Low-velocity impacts |

#### Energy Absorption Coefficients
| Material Type | Coefficient Range | Mechanism |
|---------------|-------------------|-----------|
| Soft (foam, sand) | 0.8-1.0 | Compression/displacement |
| Wood/Plastic | 0.6-0.8 | Crushing/deformation |
| Aluminum | 0.5-0.7 | Plastic deformation |
| Mild Steel | 0.4-0.6 | Plastic deformation |
| Hard Steel | 0.2-0.4 | Limited deformation |
| Ceramics | 0.3-0.5 | Fracture/pulverization |

### Ricochet Properties

#### Ricochet Probability by Material
| Surface Type | Probability Multiplier | Impact Angle Dependency |
|--------------|------------------------|------------------------|
| Water | 0.3-0.7 | High angle dependency |
| Concrete | 0.8-1.2 | Moderate dependency |
| Steel (mild) | 1.0-1.5 | Low angle dependency |
| Steel (hard) | 1.2-2.0 | Very low dependency |
| Ice | 1.2-1.8 | Temperature dependent |
| Rock/Stone | 0.6-1.4 | Surface roughness dependent |

#### Restitution Coefficients
| Material Pair | Coefficient Range | Energy Retention |
|---------------|-------------------|------------------|
| Lead-Steel | 0.2-0.4 | Low retention |
| Copper-Steel | 0.3-0.5 | Moderate retention |
| Steel-Steel | 0.5-0.7 | High retention |
| Tungsten-Steel | 0.6-0.8 | Very high retention |

### Spalling Parameters

#### Velocity Thresholds by Material
| Material | Threshold (cm/s) | Threshold (fps) | Fragment Characteristics |
|----------|------------------|-----------------|-------------------------|
| Glass | 15,000-30,000 | 500-1000 | Sharp, dangerous |
| Concrete | 30,000-60,000 | 1000-2000 | Angular, dust |
| Aluminum | 60,000-90,000 | 2000-3000 | Metal flakes |
| Mild Steel | 90,000-150,000 | 3000-5000 | Metal fragments |
| Hard Steel | 150,000+ | 5000+ | Small, high-velocity |

#### Fragment Count Guidelines
| Impact Energy | Fragment Count | Material Type |
|---------------|----------------|---------------|
| Low (<1000 ft-lbs) | 1-3 | Brittle materials only |
| Medium (1000-5000) | 3-8 | Most materials |
| High (5000-15000) | 8-15 | High-energy impacts |
| Very High (>15000) | 15-25 | Extreme conditions |

**Quality Checks:**
- Fragment count should scale with impact energy
- Brittle materials generate more fragments
- Consider computational cost vs. realism

## Validation Procedures

### Cross-Reference Validation
1. **Material Databases**: ASM International, NIST
2. **Military Standards**: MIL-HDBK, NATO STANAGs
3. **Industry Standards**: ASTM, SAE, AISI
4. **Academic Literature**: Peer-reviewed journals

### Physical Consistency Checks
1. **Density-Strength Correlation**: Generally, denser materials are stronger
2. **Hardness-Strength Relationship**: BHN ≈ 3.45 × UTS (ksi)
3. **Yield-Tensile Ratio**: Yield typically 50-80% of tensile strength
4. **Elastic Modulus**: Should match material class

### Ballistic Reasonableness
1. **BC vs. Shape**: High BC requires good aerodynamic shape
2. **Energy vs. Caliber**: Larger calibers generally have more energy
3. **Velocity Thresholds**: Should be achievable at intended range
4. **Material Response**: Should match known ballistic test results

### Common Validation Errors

#### Bullet Properties
- **Impossible BC**: Values >1.0 require careful verification
- **Mismatched Dimensions**: Diameter doesn't match caliber designation
- **Unrealistic Hardness**: Values inconsistent with material type
- **Inappropriate Thresholds**: Energy/velocity values too high/low for application

#### Material Properties
- **Inverted Strength Values**: Yield > tensile strength
- **Impossible Density**: Values outside known material ranges
- **Inconsistent Hardness**: Doesn't correlate with strength values
- **Unrealistic Ballistic Limits**: Too high/low for material thickness

### Quality Assurance Checklist

#### Before Simulation
- [ ] All values within documented ranges
- [ ] Physical relationships consistent (yield ≤ tensile, etc.)
- [ ] Units correct and consistent
- [ ] Sources documented for traceability
- [ ] Cross-referenced with multiple sources

#### During Simulation
- [ ] Results match expected physical behavior
- [ ] No obvious artifacts or anomalies
- [ ] Performance acceptable for application
- [ ] Sensitivity analysis completed

#### After Simulation
- [ ] Results compared to experimental data when available
- [ ] Peer review of critical parameters
- [ ] Documentation updated with lessons learned
- [ ] Parameters archived for reproducibility

## Recommended References

### Primary Sources
1. **ASM International Handbook Series** - Comprehensive material properties
2. **Military Ballistics Handbooks** - Validated ballistic data
3. **NIST Material Database** - Standardized property values
4. **Manufacturer Specifications** - Bullet and ammunition data

### Academic Journals
1. **International Journal of Impact Engineering**
2. **Journal of Applied Physics**
3. **Experimental Mechanics**
4. **Defence Technology**

### Professional Organizations
1. **SAAMI** - Sporting ammunition standards
2. **NATO** - Military ammunition specifications
3. **ASTM International** - Testing standards
4. **ASM International** - Materials engineering

This validation reference ensures that ballistic simulations are based on physically realistic and well-documented parameters, supporting credible research and engineering applications.