Pistol slide and gunsmithing glossary
By The Button Land Customs shop, machinists and gunsmiths
Plain definitions of the terms on our product and service pages: slide parts, optic cuts and footprints, machining, finishes, porting and FFL terms. Each one links to the parts or work it's about, so you can go from a word you don't know to the right page.
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Stripped slides and optic footprints are answered under Questions at the end.
Slides and parts
What is an upper parts kit?
The internal parts that go in the slide: firing pin assembly, firing pin safety, extractor and their springs and plungers. A lower parts kit goes in the frame. Parts kits.
What is a recoil spring assembly?
The guide rod and spring under the barrel that returns the slide forward after each shot.
What is a back plate?
The plate at the rear of the slide that holds the firing pin assembly in. Back plates.
What is a fire control unit (FCU)?
The serialized trigger and fire-control module in a Sig P320 or P365. Legally it's the firearm, so it ships to an FFL dealer. Fire control units.
What is a grip module?
The polymer grip housing of a P320 or P365. It isn't serialized; the fire control unit drops into it. Grip modules.
Optics
What is an optic cut?
A pocket milled into the slide so a red dot mounts directly on it. Optic cuts.
What are a combat cut and a race cut?
Options for the rear sight when we cut a slide for an optic. A combat cut puts a rear sight dovetail in front of the optic; a race cut removes the rear sight. A standard cut keeps the factory rear sight.
What are suppressor-height sights?
Taller sights that you can see over a suppressor, or through a red dot's window to co-witness it. Sights.
Machining
What are serrations?
Grooves cut into the slide for grip when you rack it. Front serrations are near the muzzle. Slide milling.
What is a slide window?
An opening milled through the slide to remove weight and show the barrel.
What is porting?
Holes cut through the barrel and slide that vent gas upward to reduce muzzle rise. V-ports, top ports and chunk ports are different patterns. Porting.
What is a flush cut and crown?
Cutting a barrel flush with the slide and re-cutting the crown, the edge of the muzzle. Barrel cut and crown.
What is debadging?
Milling the maker's logo off the slide. Slide milling.
Finishes and frames
What is Cerakote?
A sprayed, oven-cured ceramic coating in many colors. Cerakote guide.
What are DLC and PVD?
Very thin, very hard coatings applied in a vacuum chamber. DLC (diamond-like carbon) is one kind. Mostly black and grey, and very wear resistant.
What is laser stippling?
A grip texture lasered into a polymer frame. Stippling.
Buying
What is an FFL?
A Federal Firearms License. Serialized parts ship to a licensed dealer, who runs the background check when you pick them up. FFL transfer guide.
Pistol slide and gunsmithing glossary questions
What is a stripped slide?
A slide with none of its internal parts installed: no firing pin assembly, extractor, firing pin safety or back plate, and no barrel or recoil spring. You add those parts to finish it. Most custom slides are sold this way so you can choose your own parts.
What is an optic footprint?
The mounting pattern on the underside of a red dot: the size of its base, where the screw holes sit and where its recoil bosses are. A slide's optic cut has to match the footprint of the dot. Common footprints are RMR, RMSc, DeltaPoint Pro and ACRO.
What is a combat cut?
An option when we cut a slide for a red dot: we cut a rear sight dovetail in front of the optic, so the rear sight sits ahead of the dot instead of behind it. A standard cut keeps the factory rear sight, and a race cut removes the rear sight altogether. You choose when you book the optic cut.
What is V-porting?
A porting pattern cut through the slide and barrel in a V shape. It vents gas upward to reduce muzzle rise, and is shaped to keep flash away from your sights, which suits carry pistols. Top and chunk ports are more aggressive patterns that suit competition.