---
title: "Firearms Expert’s Testimony Excluded Because of His Limited Experience with Machineguns"
meta:
  "og:description": "Firearms expert was barred from testifying about manufacturing machineguns with a DIAS or Glock switch"
  "og:title": "Firearms Expert’s Testimony Excluded Because of His Limited Experience with Machineguns"
  author: "Expert Witness Profiler"
  description: "Firearms expert was barred from testifying about manufacturing machineguns with a DIAS or Glock switch"
---

# Firearms Expert’s Testimony Excluded Because of His Limited Experience with Machineguns

Posted on May 8, 2025 by Expert Witness Profiler

Defendant Chase Farmer was charged and convicted of multiple firearms offenses in a trial spanning April 29, 2025, to May 6, 2025. Specifically, Defendant was charged with importing, possessing, transporting, and failing to keep proper records for drop-in auto sears (“DIAS”) and Glock switches from Russia, which are machinegun conversion devices regulated as machineguns under the National Firearms Act (“NFA”).

Four days before trial commenced, the Government filed a motion _in limine_ seeking to exclude various witnesses that Defendant proposed.

The Court granted the Government’s motion in part. However, the Court took under advisement the Government’s request to exclude Defendant’s proposed firearms expert, [Tyler Hilliker](https://expertwitnessprofiler.com/expert-witness/Tyler-Hilliker/1564208). The Court explained that it had doubts that Hilliker met the qualifications for an expert witness.

## **Firearms Expert Witness**

[Tyler Hilliker](https://expertwitnessprofiler.com/expert-witness/Tyler-Hilliker/1564208) founded Hilliker Arms in 2021, and for the following two years was engaged solely in instructing on safe firearms handling and concealed carry.

He has also completed several courses pertaining to firearms.

[Get the full story on challenges to Tyler Hilliker’s expert opinions and testimony with an in-depth Challenge Study.](https://expertwitnessprofiler.com/order/add?eId=1564208&pId=3)

## **Discussion by the Court**

The Court found that Hilliker’s experience with DIAS and Glock switches is derived solely from watching others work with them, mostly on video, and relatively few times. Moreover, Hilliker’s experience with machineguns in general is limited. He has only manufactured three machineguns: two AR-15s modified with traditionalstyle sears and an Uzi.          

Moreover, Hilliker based his conclusions in his expert report on modifying an AR-15 with what he called a “traditional” auto sear—not a DIAS. Thus, there was no “fit” between Hilliker’s proffered testimony and the pertinent inquiry in this case, which involves DIAS and Glock switches specifically.

## **Held**

The Court granted the government’s motion to preclude Tyler Hilliker as an expert witness.

## **Key Takeaway:**

While Hilliker may be knowledgeable about firearms in general, it doesnot mean he is qualified to be an expert witness about converting firearms into machineguns via DIAS or Glock switch.

## **Case Details:**

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