Reference Bullets and Cartridge Cases for 

Automated Ballistics Inspection Systems 

T.V. Vorburger (tvtv@nist.gov), W. Chu, A. Zheng, T.B. Renegar, 

J. Yen, J.F. Song, J.A. Soons, R.M. Thompson 

 National Institute of Standards and Technology (NIST) 

Gaithersburg, MD 

M.G. Ols

Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) 

Ammendale, MD

AAFS 66th Annual Scientific Mtg. 

Seattle, WA 

February 21, 2014 
Contents 

• Introduction to SRM Bullets and Cartridge 

Cases 

• Topography and Microscopy Images of 

SRM Cartridge Cases 

• Reproducibility 

• Traceability and User Acquisition 

• Availability 
Funding Provided by 

• National Institute of Justice 

NIST Law Enforcement Standards Office 

NIST Standard Reference Materials Program 

Note: 

Certain commercial equipment may be identified in this 

presentation in order to specify an experimental 

procedure. This does not imply recommendation or 

endorsement by NIST, nor does it imply that the 

equipment are the best available for the purpose. 
SRM 2460 Standard Bullet and 

 SRM 2461 Standard Cartridge Case 

• For demonstrating consistency in image acquisitions 

of bullets and cartridge cases from place to place 

• Aimed at automated ballistic inspection systems, 

such as those in the National Integrated Ballistic 

Information Network (NIBIN) 

• Requires high degree of similarity from one SRM 

unit to another 
SRM 2460 Standard Bullets manufactured by 

numerically controlled diamond turning 

5	

6 Fired Masters 

40 SRM Bullets were produced and distributed. 
SRM 2461 Standard Cartridge Cases 

manufactured by commercial electroforming 

- Negatives are made from a master cartridge case 

- Positive replicas are then made from the negatives 

SRM Cartridge Cases became available in July 2012. 
Confocal microscopy used 

to acquire 3D surface 

topography images of SRM 

Cartridge Cases 

NIBIN stations at ATF’s 

National Laboratory Center 

used to acquire optical 

microscope images of SRM 

Cartridge Cases. 

Image Acquisition 

Photo: www.forensictechnology.com 
Firing Pin 

Breech Face 

Ejector mark 

Topography Images for a 

SRM Cartridge Case 

These images should be essentially the 

same for all units of the SRM. 
Firing Pin 

Breech Face 

Ejector mark 

NIBIN Golden Images for the 

Standard Cartridge Case 

Using Optical Microscopy at 

ATF National Lab. Ctr. 

These images should be essentially the 

same for all units of the SRM. 
Contents 

• Introduction to SRM Bullets and Cartridge 

Cases 

• Topography and Microscopy Images of 

SRMs 

• Reproducibility 

• Traceability and User Acquisition 

• Availability 
SRM 2461 Analysis – Breech Face 

Processing steps: 

-Trimming 

-Removal of outlier data 

-Form & noise filtering 

-Image registration 

-Correlation calculation 
NIST Statisticians participated in the analysis of the 

uncertainty estimates and control values, and 

preparation of the Certificate. 

Both SRMs and their Certificates include User 

Guides as appendices 
Two Traceability Chains NIST 

SRMs 

NIST Master Standards, 

 SRM 2460-001 ,...

SRM 2461-153,155,260,...

Golden Images 

Maintained for NIBIN 

by ATF Nat’l Lab Ctr. 

Bullet & Casing Masters 

On-Line Bullet/Casing 

Topography Images 

SRM 2460 Bullet Master 

SRM 2461 Casing Masters 

NIBIN Crime Laboratories 

SRM 2460-xxx, SRM 2461-yyy 

NIST Bullet/Casing 

Topography 

Measurement System 

SI unit of 

Length (Meter) 

Other Topography 

Measurement Systems 

SRM 2460-zzz 

SRM 2461-uuu 

IBIS Acquisition at ATF 

Nat’l Lab Ctr. 
SRM 2461 Documentation Includes a User 

Guide mainly for NIBIN Users 
Use “TRAX GOLDEN CC IMAGE” 

for control chart scores 

Example of Correlation Results for 

BrassTrax Acquisitions of SRM 2461 
Table 2. A Control Chart for Breech Face (BF) Scores of SRM 

Cartridge Case (Sheet 3 "BF") 

Date BF Score Dynamic CL Fixed CL File Name Notes 

3/23/2010 376 214 SRM2461-018-23MAR10A

4/23/2010 403 358 214 to be added

5/23/2010 368 352 214

6/23/2010 422 351 214

7/23/2010 357 341 214

8/23/2010 398 347 214

9/23/2010 447 344 214

10/23/2010 382 345 214

11/23/2010 363 342 214

12/23/2010 427 344 214

1/23/2011 414 348 214

2/23/2011 379 348 214

214

214

Excel Sheet available from NIST with Control 

Chart for Tests of SRM Cartridge Cases 
Proposed Fixed Control Limits for Acquisitions of SRM 

2461 (and 2460) Established by the National Ballistics 

Imaging Comparison Project Involving about 30 NIBIN 

Participants and their Systems 

17	

Mean Std. Dev. 

95 % 

Control 

Limit 

Breech 

Face 329 53 243 

Firing Pin 344 44 273 

Ejector 

Mark 1476 562 552 
Availability of SRM 2461 

• Available from the NIST Standard 

Reference Materials Program 

(www.nist.gov/srm) since July 2012 

• 37 units distributed 

• 100 units available 

• The certification of SRM 2461 is valid until 

30 September 2021, with proper handling. 

 
SRM 2460 Bullets not presently available 

• Currently developing a polymer replication method for 

restocking 

• See: Today, 10:40 a.m. - 11:00 a.m., Paper A170

An Improved Vacuum Casting Method for the Replication 

of Reference Bullets 

Thomas B. Renegar et al.