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Ruger SP101

• moderate
• Shop tier 2
• high confidence
• Revolver
• revolver
• double action
• modular lockwork
• no sideplate
• concealed carry
• small frame

field strip ~4 min · reassembly ~6 min · detail strip ~30 min

Specifications

Model-specific safety

• Opening the cylinder does not clear the revolver. Check every chamber individually and count them.
• The mainspring strut must be pinned before the mainspring assembly comes out, and that pin must stay in until the assembly is reinstalled. Removing it early lets the mainspring fly off the strut with great force.
• Never remove or install a loaded cylinder. A loaded cylinder can discharge if dropped or struck.
• Ruger double actions have no sideplate — the lockwork comes out as subassemblies. That makes owner-level disassembly feasible, but the manual still restricts anything beyond this procedure to factory service personnel.
• Never flick the cylinder closed.
• The .22 LR version must not be dry fired.

Under spring tension

• Mainspring and strut assembly (pin it before removal)
• Trigger return spring
• Cylinder latch spring

Easily lost parts

Mainspring seat · Mainspring strut · Cylinder latch and spring

Tools

Shop difficulty

Shop tier 2 Tier 2 — moderate among revolvers, for the full job: strip to the parts that get coated and put it back together working. Same modular Ruger takedown as the GP100 in a small frame (61 pieces): easy to the module level, but the trigger guard group holds a pawl spring and detent that launch, an awkward pawl spring pin, a spring-loaded cylinder latch and a trigger-return tunnel that is easy to damage. Moderate.

Parts: 60 numbered parts (SP101 base list; supplemental list excluded (60 line items)), from Instruction Manual for Ruger SP101 Double-Action Revolvers — Sturm, Ruger & Co., Inc., p. 33 ruger-docs.s3.amazonaws.com [1].

Bench time: about 30 min to strip, 45 min to rebuild (estimate). Estimated for an experienced tech: Ruger’s sanctioned modular takedown (grip, mainspring, hammer, trigger guard group, cylinder/crane) plus stripping the trigger guard group, crane latches and sights for coating. Rebuild is longer for the pawl spring/plunger, transfer bar and pawl alignment and the mainspring.

Small parts: 13 pins, 7 springs, 6 detents or plungers (counted from the manufacturer's parts list (one per key number unless a quantity is given))

What comes off for coating

• Grip and mainspring: grip screw, grip and locator, mainspring assembly captured on its strut with the disassembly pin — disassembly pin / paper clip
• Hammer and trigger guard group: hammer pivot and hammer (with hammer dog and spring), trigger guard assembly (latch plunger pushed through the frame hole), if the trigger guard is coated: trigger, pawl, pawl plunger and spring, transfer bar, trigger return spring assembly, cy — small screwdriver for the trigger guard plunger, pin punches, vise to hold the trigger while refitting the pawl spring
• Cylinder and crane: cylinder and crane forward out of the frame, crane latch, front latch and plungers if the frame is stripped bare, ejector, center pin rod and springs if the cylinder is coated — padded vise
• Frame: rear sight (pivot pin, elevation screw, two elevation springs), front sight (plunger-retained), firing pin, spring and plug only if required (factory-fit parts) — small punch for the front sight plunger

Special tools

• Disassembly pin (supplied, or a fitting pin/paper clip) — Capturing the mainspring on its strut; it must stay in until reassembly
• Small screwdriver/punch through the frame hole — Depressing the trigger guard latch plunger
• Bench vise with soft jaws and a gallon freezer bag — Holding the trigger while the pawl spring/plunger is refitted; catching parts
• 1/8" or smaller pin punch — Trigger guard group pins, sight pins

Known pain points

• Squeezing the loose trigger group moves the pawl and frees a spring and detent that launch and are lost. (disassembly)
  Source: Do-It-Yourself Ruger SP101 Trigger Job — Shooting Times shootingtimes.com [5] — “This will move the pawl (which rotates the cylinder), and a spring and detent under the pawl will be exposed and go ballistic into never-ever land (never-ever going to find that part).”
• The pawl spring pin is awkward to push in against heavy spring pressure; a vise and a plastic bag help. (reassembly)
  Source: Do-It-Yourself Ruger SP101 Trigger Job — Shooting Times shootingtimes.com [5] — “The pawl spring pin is in an awkward place and pushing it in was awkward. Consider doing this in a plastic bag to contain the pawl spring/pin because it is under a lot of pressure and a little slip will have you chasing parts.”
• The cylinder latch is under spring pressure and its spring and plunger escape if it is moved too far sideways. (both)
  Source: Do-It-Yourself Ruger SP101 Trigger Job — Shooting Times shootingtimes.com [5] — “It’s under spring pressure, so secure it down with a rubber band or tape.”
• The lip at the end of the trigger-return spring tunnel captures the plunger; damaging it means a new trigger guard. (both)
  Source: Do-It-Yourself Ruger SP101 Trigger Job — Shooting Times shootingtimes.com [5] — “You don’t want to damage the lip at the end of the tunnel because it captures the plunger. If you damage it, you’ll have to buy a new trigger guard!”
• The mainspring must stay captured on its strut with the pin until the assembly is back in the frame. (both)
  Source: Instruction Manual for Ruger SP101 Double-Action Revolvers — Sturm, Ruger & Co., Inc. ruger-docs.s3.amazonaws.com [1] — “When the hammer is cocked, the pin can be removed (it will fall free).”

Fit or check on rebuild

• Pawl and transfer bar positioned so the trigger guard swings home without resistance; trigger rotates and locks the cyli — Ruger’s own reassembly check.
  Source: Instruction Manual for Ruger GP100 Double-Action Revolvers — Sturm, Ruger & Co., Inc. ruger-docs.s3.amazonaws.com [6] — “if the trigger guard will not lock into position, re-check the position of the pawl and transfer bar”
• Timing / carry-up and cylinder lockup in single and double action; dry fire both ways — Ruger asks for single- and double-action dry fire after reassembly; worn pawl or cylinder stop gives the "does not lock up" fault (entry commonIssues).
• Hammer and trigger side play (shims) where fitted — SP101 manual reassembly puts hammer shims either side of the hammer; Shooting Times measures side play with a feeler gauge.
  Source: Instruction Manual for Ruger SP101 Double-Action Revolvers — Sturm, Ruger & Co., Inc. ruger-docs.s3.amazonaws.com [1] — “insert the hammer into frame with the hammer shims on either side of the hammer”
• Crane, front latch and cylinder latch lock the cylinder closed; cylinder spins free with no drag — Ruger’s function check (cylinder must spin freely; hammer must not cock with the cylinder open).

This is Pew-Takedown's rating, not the manufacturer's. How tiers are rated. Forum reports are owners' experience, not specifications.

Manufacturer videos

Official videos from Sturm, Ruger & Co.'s own channels, linked rather than copied. Where a video and the steps on this page differ, follow the manufacturer's manual and video.

• Ruger Double Action Revolver Disassembly RugerFirearms field strip · 2009-04-16
  Covers: Ruger double-action revolvers SP101, GP100 and Redhawk (per the video description)
• Ruger Double Action Revolver Reassembly RugerFirearms reassembly · 2009-04-16
  Covers: Ruger double-action revolvers SP101, GP100 and Redhawk (per the video description)
• Ruger Double Action Revolver Cleaning RugerFirearms cleaning · 2009-04-16
  Covers: Ruger double-action revolvers SP101, GP100 and Redhawk (per the video description)
• Tech Tip - Double-Action Revolver Disassembly Ruger Firearms · plays on ruger.com field strip · 2016-04-14
  Covers: Ruger double-action revolvers (generic; models not stated)
• Tech Tip - Double-Action Revolver Reassembly Ruger Firearms · plays on ruger.com reassembly · 2016-04-14
  Covers: Ruger double-action revolvers (generic; models not stated)
• Tech Tip - Double-Action Revolver Full Cleaning Ruger Firearms · plays on ruger.com cleaning · 2016-04-14
  Covers: Ruger double-action revolvers (generic; models not stated)

Procedures

Patent drawings

not under copyright

Drawings from US patents on this design. A patent shows the invention as the inventor filed it; the firearm that shipped can differ in detail, and later production often does. Use them to see how the parts relate, not as a parts reference or a procedure. Per the USPTO, the text and drawings of a patent are typically not subject to copyright; each patent here was checked for a copyright notice.

US Patent 11,215,417 — Safety mechanism for hammer-operated firearms

Jonathan Philip MATHER, Andrew James Beland, Geoffrey William Smith, Kenneth Bruce McLoud, Eric Mitchell Callum, Jonathan Barrett · assigned to Sturm, Ruger & Company, Inc. · filed 2020-07-29 · granted 2022-01-04. Full patent (USPTO)

A Ruger double-action revolver's hammer, transfer bar/blocking-pin safety and lockwork in the frame.

Why this is the Ruger SP101’s patent: listed on the maker’s patent-marking page — Ruger Patents — Sturm, Ruger & Co., Inc. ruger.com [4]: “Ruger SP101® 11,215,417”

Torque specifications

No sourced torque values from the manufacturer are recorded for this firearm. Where a fastener has a specified torque — action screws, scope bases, muzzle devices, barrel nuts — get it from the manufacturer or a gunsmith rather than estimating it.

What the manufacturer does say: The manufacturer's documents give no torque value. They say: "Install and tighten grip panel screw." (Instruction Manual for Ruger SP101 Double-Action Revolvers, PDF p. 25)

Materials and factory finish

As stated by Sturm, Ruger & Co.. Prep, masking and cure depend on these; a polymer or aluminium part, a nitrided or anodised finish, and a blued steel part are each a different job. Variants with other finishes may exist — check the maker's page for the exact SKU on the bench.

Parts list

Transcribed from the manufacturer's parts list (Instruction Manual for Ruger SP101 Double-Action Revolvers — Sturm, Ruger & Co., Inc., p. 33 ruger-docs.s3.amazonaws.com [1]) — SP101. Exploded view on p. 34. Key numbers refer to the exploded view in that document.

Function check

• Again, be certain the revolver is unloaded before any check.
• Visually inspect the revolver to ensure no components are damaged, missing, loose, bent, cracked, chipped, or peened.
• Open and close the cylinder and confirm it latches securely.
• Cock the hammer slowly and confirm the cylinder indexes and locks up at each chamber before the hammer reaches full cock.
• With the hammer at full cock, confirm the cylinder is locked with only minimal rotational play.
• Dry fire in single action and in double action through every chamber to confirm all parts are working properly.
• Confirm the trigger guard assembly is fully latched into the frame.
• If you observe excessive wear, stop using the revolver and contact customer service.

Maintenance

Lubrication points

• Crane where the cylinder rides
• Ejector rod
• Hammer and trigger pivots (one drop each)
• Cylinder latch

Cleaning notes

Clean the cylinder face and forcing cone thoroughly. If you shoot .38 Special in a .357 chamber, scrub the resulting carbon ring out or .357 rounds will not seat properly later.

Suggested inspection interval: roughly every 2000 rounds. This is a general guideline, not a manufacturer specification.

Wear parts to inspect

Hand · Cylinder stop · Forcing cone · Ejector rod tightness · Firing pin and return spring

Common issues

Similar manual of arms

• Ruger GP100

Sourcing