Editing Handloading (section)

=== Case trimmer ===
[[File:Hornady Case Trimmer.jpg|thumb|right|Hornady Manual Case Trimmer]]
Cases that have been fired and reloaded numerous times will need trimming due to brass flowing forward during firing, especially bottleneck cases. How much a case will grow depends upon load pressure, cartridge design, chamber size, functional cartridge headspace (usually the most important factor), and other variables. Periodically cases need to be trimmed to bring them back to proper specifications. Most reloading manuals list both a ''trim size'' and a ''max length''. Long cases can create a safety hazard through improper headspace and possible increased pressure.<ref name=nonte_2 />

[[File:Lee Trimmer.jpg|thumb|Lee hand trimmer]]
Several kinds of case trimmers are available. Die-based trimmers have an open top and allow the case to be trimmed with a file during the loading process. Manual trimmers usually have a base that has a shellholder at one end and a cutting bit at the opposite end, with a locking mechanism to hold the case tight and in alignment with the axis of the cutter, similar to a small lathe. Typically the device is cranked by hand, but sometimes they have attachments to allow the use of a drill or powered screwdriver. Powered case trimmers are also available. They usually consist of a motor (electric drills are sometimes used) and special dies or fittings that hold the case to be trimmed at the appropriate length, letting the motor do the work of trimming.<ref name=nonte_14 /><ref name=trimmers>{{cite web|url=http://www.forsterproducts.com/Pages/case_trimmers.htm |title=The Forster Case Trimmer System |access-date=2007-09-14 |archive-url=https://web.archive.org/web/20070405020430/http://www.forsterproducts.com/Pages/case_trimmers.htm |archive-date=2007-04-05 |url-status=dead }}</ref>