FT Blog Posts

Firing Pin Shapes | To Glock or Not to Glock...

Posted by Andrew Boyle on November 2, 2016 1:10:58 PM EDT


New manufacturing developments with Glock firearms has brought forward the question of when “Glock” should be selected as the Firing Pin Shape while creating an IBIS cartridge case exhibit.  To give the most comprehensive answer we first have to review the philosophy behind how IBIS is used.

 While the end result of IBIS searches are used by firearm examiners to link previously unrelated crimes, the core purpose of IBIS has always been to be a system operated by technician-level users until the expert was needed for final confirmations.  As such, when a user is classifying the firing pin shape their focus should be on “What does this look like?” rather than “What could have fired this?”  The former being a basic diagnosis of the shape in front of them while the latter is more analytical in nature, which would require a more advanced knowledge set.

The requirement for choosing the firing pin shape from the drop list options must come from the features present on the exhibit itself, which is always in-hand, as opposed to gun that fired it, which would only be a certainty for test fires taken in-house.


For an exhibit to be classified with a “Glock” firing pin shape there must be an elliptical firing pin impression surrounded by rectangular flowback. 

Glock-Traditional_Brass.pngThe only firearms known to produce these markings are Glock, Smith & Wesson’s Sigma series of pistols and, more recently, Springfield Armory’s XDS9 pistol.  Regardless of the firearm make these would be classified as Firing Pin Shape: Glock.


In 2014 Glock modified their manufacturing process resulting in new breech face and firing pin markings. 

This began with their Model 42 and 43 pistols, in 380 Auto and 9 mm Parabellum respectively, but there is reason to believe more Glock models will be produced in this new style as time goes on.



The elliptical-shaped firing pin has been replaced with one more round in nature, though it does seem to have a flat edge to it at the 9 o’clock position when orientated for IBIS acquisition. Also gone is the rectangular flowback, which has been replaced with a shear mark extending to the left of the firing pin impression. With only these features to go by these cartridge cases should be entered as Firing Pin Shape: Circle.


There will be an urge to label these as “Glock” when test fires are taken in your laboratory with a Glock pistol in hand.  However, priority has to be given to the crime scene scenario where cartridge cases were recovered but no weapon was found.  If cartridge cases with these markings are classified in IBIS as “Glock” when lab-fired but “Circle” when recovered from crime scenes you’ve created an environment where no matches will be found between cartridge case evidence and recovered weapons.  The rule must be to label the firing pin shape according to the markings present on the primer’s surface regardless of the make/model gun that fired it.



S&W Sigma

Each of these depict an elliptical FP impression inside rectangular flowback = FP Shape: Glock

glock_shape_circle_icon.pngNEW GLOCK MARKINGS AS SEEN ON G42 & G43 PISTOLS

Glock 42

Glock 43

Predominantly round FP impression = FP Shape: Circle