Privately made firearm in the US: results from a national survey

TL;DR

A national survey estimates that around 10 million privately made firearms are owned by U.S. adults, with half of them not having serial numbers.

Contribution

The study provides the first nationally representative estimates of privately made firearm ownership in the U.S.

Findings

Approximately 10.1 million privately made firearms are owned by U.S. adults.

Half of these firearms are unserialized.

Recently acquired privately made firearms are more likely to be serialized than older ones.

Abstract

Almost nothing is known about the size or composition of the stock of privately made firearms (PMF).

Estimate the size and composition of the U.S. PMF stock.

A probability-based online survey of US adults conducted in December 2024 were used to generate nationally representative estimates. 12,907/ 20,907 adults (59%) responded to the survey invitation; 4,059 owned a working firearm. Respondents were asked whether they owned PMFs, defined as “firearms that were NOT produced by a manufacturer (sometimes called privately made firearms), such as guns that were assembled from a kit, 3-D printed or otherwise put together” and if so, how many and what types. They were also asked about their most recent PMF acquisition.

We estimate that 2.9 million [CI: 2.2 million, 3.8 million] US adults own approximately 10.1 million PMFs. Most were constructed from kits (34%) or unfinished parts (32%); 16% were 3D printed, and the remainder were machined from raw materials (18%). Half 49% [CI: 0.43, 0.53] were unserialized. Among US adults who last acquired a PMF within 24 months of the survey, 67.2%, [CI: 48.7, 81.6] had a background check for their most recent acquisition, compared with 45.2% [33.9, 56.9] for PMF owners who last acquired a PMF > 24 months prior (P < 0.05). Comparable statistics for serialization were 68.9% [CI: 51.7, 82.1] and 53.8% [42.2, 64.9] (P = 0.14).

Approximately half of the 10 million PMFs owned by US adults were not serialized. More recently acquired PMFs are more likely to be serialized.