Ruger GP100 revolver: review

The Ruger GP100 revolver series represents reputedly the most rugged and reliable revolver ever made, with a tempting selection of different models and variants available offering cylinder capacities of 6, 7, 8 or 10 shots.

This is a very heavy handgun. Most GP100 models are chambered in .357 Magnum (which can also fire .38 Special) and the extra weight of the GP100 helps to absorb the significant recoil from those .357 Mag loads. The chunky Full Underlug (incorporating the the rod shroud) also serves as a counter-weight to reduce muzzle flip while making the frame practically indestructible. Often described using terms like “over-built”, “built like a tank”, “last a lifetime”, this hefty big iron comes with a brushed stainless look with rugged adjustable target-grade OEM sights. This is the sidearm I’d want if a grizzly bear is charging at me.

The GP100 is demonstrably more reliable than other revolvers, for example having a more potent hammer strike than a Model 19 Smith & Wesson (e.g. 3 different cartridges that had failed primer or light-strikes in the Model 19 when tested in the GP100 all fired). The GP100 works when you pull the trigger, when you need it to, and what could be more important than that?

The GP100 seems constructed to withstand thermonuclear armageddon. In most models, mine included, the metal of the frame and core components is 410 Stainless Steel. This is a martensitic stainless steel alloy, selected by Ruger because it responds exceptionally well to heat treatment, creating high tensile strength and hardness (comparable to the 4140 chrome-moly steel used in blued revolvers). Ruger operates its own world-class foundry, Ruger Investment Casting. This process allows Ruger to cast the frame as a single, solid slab of metal, without a removable side plate, thus eliminating an important structural weak point traditionally found in many other wheel-guns. Even the grip is bomb-proof, thanks to the grip peg design anchoring it in place. There is no metal backstrap, no traditional grip frame, and no beaver tail built in, so changing the grip module can greatly adapt the ergonomics. This is a trusted companion to many outdoorsmen, and its spacious trigger guard leaves plenty of room for thick gloves — handy in deer season. The GP100 may be more appealing as a nightstand weapon than a concealed carry.

The GP100’s cast steel is isotropic, exhibiting equal physical properties in all directions. In comparison, forged steel is strongest along its grain. Ruger’s investment casting under a vacuum results in a uniform, non-directional grain structure, providing multi-directional strength. This steel has equal tensile strength in every direction, which means the metal is affected uniformly by the multi-directional explosive forces unleashed by a .357 Mag cartridge. Because cast steel is slightly less dense than forged steel, Ruger compensates for this with a thicker frame, underlug and top strap. That’s why a GP100 can withstand over 50,000 full-power heavy .357 Mag loads without distorting the frame or losing mechanical timing. In a stress test by C&G Firearms in the UK (RFD Herts 221) it took about 14 tonnes of pressure to deform a GP100 cylinder, at which point the cast steel structure collapsed instantly, generating a small explosion presumably resulting from adiabatic compression and frictional heating.

Upon opening the crane of a GP100, note the spring-loaded latch that retains and locks the cylinder into the frame as close as possible to the cylinder. (This is in contrast to the crane being held into place by a small detent at the front of the ejector rod.) This is one of the features that makes it so robust. The triple lock design locks the cylinder in position at three different pints, for maximum resilience and shot precision. A transfer bar safety mechanism ensures that the hammer cannot strike the firing pin unless the trigger is pulled.

The GP100 is easy to field-strip and maintain for routine cleaning, although a full teardown requires a tool and can be tight. The trigger assembly pops out as a single unit, with no removable side plate or tiny parts. Aftermarket parts like trigger upgrades are widely available for this revolver, being one of the most popular revolvers of our time, but the factory parts and specs are perfect for me and I would not change a thing. In the US replacement parts are widely available, on eBay you’ll fund everything from a single spring to the complete cylinder and crane assembly with ejector. Parts are also widely available from online retailers internationally including Europe. Some parts are interchangeable between Ruger’s GP100 and Redhawk. The GP100 manual includes useful exploded parts diagrams. In the unlikely event that you ever need to remove or disassemble the cylinder assembly, and in any further disassembly, I recommend letting an experienced gunsmith take care of that, and take care with the tiny springs and be mindful that putting certain small parts back in place can be very fiddly, particularly certain small pins and plungers, one of which requires you to press and hold the correct mechanism to open up the corresponding hole. Very consistent and interchangeable parts were observed between different GP100s from the same batch as mine with sequential serial numbers, even the cylinders could be swapped without machining, although officially each cylinder is fitted for its specific frame. Very consistent trigger pull weights were measured between different GP100s from the same batch.

Inevitably the GP100 series will be weighed (literally and metaphorically) against comparable alternatives such as Smith & Wesson’s 686 series. The GP100 is quantitatively more reliable. The GP100 is quantitatively more durable, with performance sustained or even improved after 50k rounds while the 686’s timing and other performance metrics tend to deteriorate around the 10k rounds mark. The Colt Python is refined but much more expensive. Ruger’s own Super Redhawk is a competitive rival to the GP100, but is less versatile for varying loads.

When the GP100 was first released in 1985, revolvers were the most common form of service pistol for law enforcement in the US, primarily .357 Mag, sometimes with .38 Spl backup. The GP100 series is the 2nd generation of the original Security Six series, Ruger’s standby .357 Mag revolver, the GP100 being even more robust. (The brand name Security Six referred to the target market, private security and law enforcement, and the gun’s capacity.) A GP100 is designed to comfortably withstand the highest-pressure .357 Mag rounds. The GP100 drew inspiration from the Ruger Red Hawk and incorporates some of its robust features. The GP stands for General Purpose but this platform was soon widely adopted by law enforcement. In the early 90s it became the issued sidearm for officers in US Border Patrol and also Immigration before they switched to .40 calibre in 96. It has been adopted by special forces in various countries including the UK, Greece and Serbia.

Personally, although I’m more accustomed to using 9mm semi-auto pistols like my SIG P320, I do also train with revolvers and have used this form factor at shooting clubs internationally. (Coincidentally, both my P320 and my GP100 were manufactured in the same US state, New Hampshire.) A revolver offers a different shooting experience, and it’s hard to beat the stopping-power of a .357 Magnum for military, law-enforcement and home-defensive usecases. (Projectiles in .357 Mag / .38 Spl are heavier than those in 9mm, despite the diameter being only a negligible 0.0508 mm bigger.) Importantly, the large frame of my GP100 allows me to use my preferred thumb-over-thumbnail grip to hold the gun, thus benefitting from the same muscle-memory I’m developing when training with my 9mm semi-auto. (On smaller revolvers, thumbs-forward grips can be dangerous, exposing your support hand’s thumb to hot gas and even debris escaping from the breach through the cylinder gap, especially with my big hands.) I cannot find a superior tool for humane dispatch of large animals that fits in the glove compartment of my pickup truck or in an OWB holster on my hip. My order of preference for holster depends on the usecase, e.g. for woodland/hunting carry it’s in either a chest holster, a tactical thigh rig, or cross-draw OWB. The GP100 has the inherent safety of a revolver, requiring the trigger to be pulled to fire, and is drop-safe by design.

The kick of my 4.2″ GP100 is surprisingly comfortable and manageable. The felt recoil from a single shot with my GP100 using .357 Mag 158gr does not feel much different to a single shot with my P320 Compact 9mm 115gr. The metal of my 4.2″ GP100 in my big hands absorb the recoil very well. Naturally, a follow-up shot is much more clunky with the revolver, whether manually cocking it into single-action mode again or squeezing through the double-action, so staying on target between shots is more of a challenge. However, after 100 shots I can feel within my hand the extra work of managing .357 Mag recoil.

Obviously GP100 models with the longer or 6″ barrel will produce greater muzzle velocity and thus more terminal energy and a flatter trajectory. For me, the 4″ models are optimal, being significantly more compact and lighter and with a similar trajectory at practical ranges of 50m and even up to 100m. (E.g. my preferred .357 Mag 158gr bullet fired from a 4.2″ barrel would incur around 1″ more bullet drop at 100m vs a 6″ barrel.) The practical maximum range for most shooters to achieve acceptable accuracy with a .357 Mag revolver is around 50m. My own current GP100, a model 1705, has the perfect balance of different considerations. I also appreciate the friction, comfort and resilience provided by the rubbery thermoplastic elastomer (TPE) OEM Hogue grip on my model which is the most modern type of grip for a GP100. My synthetic grip is tough and can be swapped by removing the screw at the base. And even the grip of this gun is bomb-proof, thanks to the grip peg anchoring it in place. That said, I do also have a Hogue Coco Bolo wooden grip, because the GP100 is, after all, a coveted collector’s item as well as a tool.

My dream GP100 model, if it were not simply a pragmatic tool, would probably be Model 1784 with a classic checkered hardwood grip, elabourate decorative engraving and HIVIZ Fiber Optic front sight. But a GP100 is fundamentally a utilitarian machine, optimised for reliability and longevity.

For competition target shooting consider the GP100 Match Champion variants, offering improved balance, speed, and accuracy compared to the standard, utilitarian GP100. If you need 8 shots try the Super GP100 model. The .327 Federal Magnum variant holds 7 rounds, while the 22LR holds 10. You get 5 shots in .44 Special.

The .357 Magnum is arguably the most versatile handgun cartridge ever produced. To date, I think it offers the optimal balance of power vs control, making it difficult to beat as general purpose or all-purpose ammo. It was developed by Smith & Wesson, who also developed the “.44 Magnum” cartridge which delivers almost double the muzzle energy of a .357 Mag. (It would be “deer-legal” in the UK for the two “small deer” species, MJ and CWD, if pistols were allowed!) That extra power, of course, makes the hand-cannon much more difficult to control for accurate rapid follow-up shots. (In the famous movie, Dirty Harry, to make it look more manageable Clint Eastwood used low-recoil .44 Spl theatrical blanks in his Smith & Wesson Model 29 with a 6.5″ barrel.) My favourite and most used rifle is my M&P15-22, so I’m something of a S&W fanboy. The ammo I prefer carry with my GP100 is Hornady .357 Mag 158gr XTP.

In conclusion, a GP100 revolver is ultra-reliable handgun which, through almost half a century, has earned its reputation as an iconic and versatile firearm that’s built to last a lifetime. In fact, it will last for generations and improves with age like a fine wine, it’s an heirloom firearm.

GP100 zeroing and ballistics

The factory zero for a GP100 is presumed to be intended for a .357 Mag 125gr load with a Six O’Clock Hold sight picture. For heavier loads, aim lower (turn elevation screw clockwise). (Using a Center Hold sight picture out of the box would obviously print higher.)

The sight radius, geometry and rear sight configuration of a GP100 could indicate an intended 2 MOA per click on average, but of course a longer barrel reduces the MOA of each click. The GP100 manual reports 3/4″ per click at 25y, which would be about 3 MOA, but clearly that will differ with barrel length.

At 25y with my GP100 4.2″, 1 click of adjustment on the rear sights moves the point of aim by ~0.5″ which is ~2 MOA. Without fitting match-grade sights on my GP100, with the factory sights I would expect a small deviation in MOA between different clicks (up to approx. +/-0.25). Technically, a 3″ barrel would give 0.75″ to 0.81″ per click at 25y (~3 MOA) if these models had adjustable sights. My 4.2″ barrel is expected to give 0.52″ to 0.55″ per click at 25y (~2 MOA). A 6″ barrel is expected to give ~0.4″ per click at 25y (~1.5 MOA).

Out of the box, at 25m with .357 Mag 158gr my GP100 4.2″ grouped ~11.5″ high and ~3.75″ left. Note that I’m working in meters, whereby at 25m it’s ~0.55″ per click. I corrected the windage (side screw) with 7 clicks right (counter-clockwise). For .357 Mag 158gr, I can adjust elevation (top screw) 21 clicks down (clockwise). A .38 Spl 158gr should print 1″ to 2″ inches higher, so for that cartridge I need 3 clicks down from my .357 Mag zero (or aim ~1.5″ low). Fresh from the factory, the sight blade looked visibly offset from centre by, I guess, about a millimetre, and the notch does now look central to my eyes.

A heavier load prints higher because it is slower and thus spends longer in the barrel (by a fraction of a millisecond) during the upwards muzzle flip induced by recoil, and intuitively this effect is amplified by longer barrels. A 158gr projectile prints 1″ to 2″ inches” higher in .38 Spl vs .357 Mag because the smaller cartridge propels a lower velocity.

This Recoil “Dwell Time” Paradox is counter-intuitive, because heavier bullets fall faster, but in a .357 Mag revolver this is eclipsed by the effect of recoil. E.g. With my 6.5 Creedmoor rifles, the bullet is so fast that it exits the barrel before most of the muzzle flip is registered, and overall muzzle flip is also 500% shallower for that long heavy rifle barrel.

Hence, zeroing this gun is a somewhat personal exercise. The click values for a .357 revolver with a 4.2″ barrel significantly depend on who is holding it and how. You’re zeroing it for your own hold, whereas somebody else would probably need different click values. For instance, my own big hands, tight grip, and locked-wrists technique might absorb more of that strong muzzle flip. Thus, using the same gun and zero, somebody with smaller hands or just a different technique with might punch holes 4″ higher than I do, unless they adjust the rear sights for own particular grip. You’re zeroing your entire setup. The results can change if you alter your stance, move your head, sit down, shoot one-handed, rest the barrel on something, change your gloves, etc.

Specs of my current GP100 revolver which I bought brand new — Model 1705 (factory catalog number KGP-141) – serial 179-569xx manufactured in Newport, NH, USA, shipped in 2022, acquired privately in FL, USA in 2023 within a batch of several hundred (with sequential serial numbers) to be imported into the UK for a private contract:

• Capacity: 6-shots (note that certain GP100 models have a capacity of 7 or 8 in the cylinder)
• Calibre: .357 Mag / .38 Spl
• Trigger action: Double-Action (12-14 lbs) / Single-Action (4-6 lbs) – feels 2-stage in DA mode – a smooth action with a crisp predictable break
• Barrel length: 4.2″
• Overall length: 9.5″
• Weight: 40 oz.
• Rifling twist: 1:18.75″ RH
• Rifling grooves: 5
• Rear Sight: Adjustable
• Front Sight: Ramp (top of rail is serrated to reduce glare)
• Cylinder release: push-button
• Material: Stainless Steel (cast, not forged)
• Finish: Satin Stainless
• Grip: Hogue Monogrip (wrap-around polymer grip – durable, ergonomic over-molded thermoplastic elastomer [TPE] “rubber” over a rigid endo-skeleton)
• Safety: transfer bar
• Fluted cylinder: yes
• Checkered hammer top: yes
• Catalog: KGP-141
• UPC: 7-36676-01705-8
• Suggested Retail: $1,109
• GP100 OEM instruction manual

I was inspired to write this review when Ruger discontinued production of the GP100 on 13 October 2026, along with other models listed in their announcement to distributors that day. Manufacturing complexity was one of the reasons cited. Revolvers are among the most labour-intensive firearms to manufacture, and the indestructible GP100 is a feat of engineering. The marketplace for handguns is now dominated by semi-auto pistols. The GP100 product page was removed from Ruger’s website the same day. The Super GP100 remains on the website. (Fortuitously, I had been planning to write this review for some time and happened to archive many of the GP100 web pages and images from Ruger’s website in the week preceding the announcement, while compiling my notes, because I tend to archive important web pages that I link to in my reviews for posterity.)

Postscript on 25 Oct 2026: GP100s have been selling like hot cakes since the news broke, and stocks are already depleted with prices rising for these cherished tools both new and used. GP100s available to buy rapidly became rare in the US and are almost impossible to source internationally, especially for example in the UK where there was already a 1 year lead time to obtain a model not in stock.

In the UK handguns are an extremely niche market. Almost all firearm owners in the UK enjoy do so through the privilege of holding a “Firearm Certificate” (aka “FAC” aka “ticket”). For each type and calibre of firearm somebody owns in the UK, they require specific permission in advance from their local police force, and that permission is only granted if they can demonstrate sufficient need, e.g. membership of a club or running a pest-control company. However, an FAC authorises only Section 1 firearms. (This is different to Spain, for instance, where you can go to a shop and buy most guns and ammo freely after obtaining the licence.) Section 5 firearms, which includes all standard handguns along with the GP100, are strictly prohibited for civilians. Almost nobody in the UK can own a pistol, ever since the Firearms (Amendment) Act 1997. An established member of a shooting club in the UK can only own a GP100 if it is permanently modified by adding both a 12″ (30cm) barrel and a metal tail-brace extending from the grip to make the total length at least 24″ (60cm).

My own personal GP100 is a standard factory-spec model 1705, this being the short-barrel (4.2″) version with an overall length of 9.5″ (24cm), which is therefore unavailable to the civilian market except for those who hold a Section 5 licence, individuals with formal government authorisation including certain military personnel, or as legislated under Section 3.

The UK importer of Ruger firearms, Viking Arms, does not advertise the GP100 on their “sporting” civilian market website, because UK advertising regulations ban the marketing of Section 5 Prohibited Weapons to the general public who legally cannot obtain them. (The “defense” military and police arm of Viking Arms also does not advertise the GP100 on their website.) A very small number of specialist s 5 firearms dealers (e.g. Shoot Day Services, Tactical Solution, CG Firearms, BH Firearms) are authorised to supply revolvers to the extremely small number of approved s5 users in Britain, with all s5 services are strictly by private appointment only.

Technically, a GP100 bullet does not meet the legally required energy threshold for hunting large game in Britain, but under certain circumstances the GP100 may be legally used for dispatching a wounded animal such as a horse or wild deer e.g. under Deer Act 1991 Section 6 (3), (4), (4A) as amended by the Regulatory Reform (Deer) Order 2007.

Recommended accessories for the GP100 revolver

• Grips
  • Hogue grips for GP100 (Hogue Europe)
    • OEM Hogue overmolded rubber monogrip – black (SKU 80000) | Shop Ruger (Item Number 84139) | Amazon US
  • HRV Customs (ships internationally)
  • Optics Planet (ships internationally)
    • Hogue – GP100 – Coco Bolo – Top Finger Groove – Checkered – 80851 [includes stirrup, mounting pin, and screw – perfect fit for replacing the OEM rubber Hogue grip – note that a GP100 with a factory Hogue rubber grip uses the standard full-size GP100 frame pin setup]
  • Brownells (UK)
  • KSD via Havrin – Walnut – Diamond, Walnut – Dragon Skin
  • Altamont GP100 grips (USA – usually includes panel screw, cross-locator pin)
  • Note: that the ergonomics are dictated by the grip, from aftermarket big butt contoured target stocks to discrete compact options.
• Holsters
  • Craft GP100 4″ holster | OWB | belt side nylon | OWB – thermo-moulded Cordura
  • Triple K holsters for GP100 4.2″
  • Azula – GP100 4.2″ | Cross-Draw Outdoor with rerention strap | What I use: OWB – 2 Slot Pancake Holster – Classic Leather – Dark Brown (OWB pancake – international | cross-draw – international)
  • Galco Dual Action Outdoorsman (DAO) for GP100 4.2″ or Wheelgunner 2.0 Belt Holster (OWB) for GP100 4.2″ and others
    • International: DAO334 (tan) | DAO334B (black)
  • Ruger GP100 Triple K Belt Holster, RH, 4.2″ Barrel (other Triple K holsters)
  • OutBags USA NSC09 (Right) Nylon OWB
  • Holsterwelt (EU and UK)
• Hard cases
  • Seahorse SE-430 (snuggest fit) [internal 30,15 x 22,78 x 13,08 cm]
  • PELI 1400 or Peli 1200 for very snug diagonal fit
  • MEIJIA 13.35″ [internal Length 11.81inch Width 8.87inch Height 5.18 inches]
• Ruger accessories for GP100 including the OEM hard case with red latches (as supplied with “Match Champion” models)
• Tools
  • Rear sight adjustment (zero at 25m) – gunsmithing screwdriver: 1.8 or 2mm (5/64″) flat head slotted (parallel-cut or hollow-ground):
    • Wera Kraftform 2035 Micro Screwdriver Slotted Tip 1.8mm (05118004001)
    • Wheeler 36pc Spacesaver Screwdriver Set (4001005)
    • Wheeler 43 Piece Gunsmithing Screwdriver Set
    • NOTE: avoid jeweller screwdrivers whose blades are too thin, avoid standard household screwdrivers with tapered blades.
• Gloves – Mechanix – Men’s FastFit Gloves Covert – Black (FFTAB-55-010)
• Safety glasses rated ANSI Z87.1+: LITE Conqueror Tactical Eyewear – 5 Safety Cert. Military-Grade Eyewear
• GP100 guns and parts
  • Europe
  • Spain (Borchers is the official Ruger importer)

Recommended ammo

• Grizzly – .357 Mag – 200gr WLNGC – when you have 1 second to stop a charging grizzly bear. The GP100 can handle this, it was practically made for it. Wide Long-Nose, Gas-Check load. This hunting usecase requires a heavy load with an immutable flat nose. Caveat: you likely have 1 or 2 seconds to take the shot and if you miss the brain/spine a prime male grizzly will likely live for 10 to 30 seconds (versus 60 to 120 seconds for 158gr). 200gr is more likely to shatter major bones to bring the bear down. Be ready to to deliver follow-up shots at point-blank range. A 210gr load is not recommended for grizzly country because this degrades performance too far.
• Double Tap – 357 Mag – 200gr Hardcast Solid – Wide Flat Nose Gas Check Hardcast for 30 to 45 inches of linear penetration on a big dangerous animal when you need it most.
• Hornady
  • .357 Mag – 158gr XTP – Custom (Item #90562) (optimal for duty/defense use, medium game and humane dispatch, the Extreme Terminal Performance projectile provides deep initial penetration followed by controlled expansion, reducing over-penetration, ricochet risk is medium to high)
  • 38 Special – 158 gr XTP – Custom (Item #90362) (optimal for duty/defence use, varmint and humane dispatch, obviously a lower power cartridge vs 357 Mag.)
• Magtech
  • .357 Mag – 158gr – FMJ Flat (357D) (suitable for training usecases – does not expand or fragment, high potential for over-penetration albeit less than a round nose, high risk of ricochet and shrapnel) – note that a flat nose projectile packs more punch, it’s is stronger at the tip thus deforms less, less streamlined and thus encounters more resistance, so the flat edge and greater meplat transfers more energy and does more damage whether or not it passes through the target. [Many folks do use this round for HAD of large animals such as bulls or shire horses.]
  • .357 Mag – 158GR LFN “Cowboy Action” (357L) (lower power, less recoil – for training usecases, target competitions and humane dispatch, but – does not expand or fragment, potential for over-penetration, high risk of ricochet albeit with lower energy, fowls barrel with lead, use FMJ for duty usecases)
• Sellier & Bellot
  • .357 Mag – SJHP – 158gr (V312032) – duty/defence, training/target, perfect for humane dispatch of medium animals (rapid expansion, also more power than SP/FMJ/LFN)
  • .357 Mag – SP – 158gr (V311432) – duty/defence, training/target, humane dispatch of larger animals (penetrates thicker bone than SJHP)
  • .357 Mag – LFN – 158gr (V311882) – training/target round, human dispatch (slightly lower power, minimal deformation, over-penetration high risk)
  • .357 Mag – FMJ – 158gr (V311392) – training/target round (over-penetration high risk)
  • .357 Mag XRG-D 110gr (V312532) – duty/defense, humane dispatch (light, lead-free)

Other GP100 reviews

• GP100 review (Sootch00)
• GP100 review (Texas Gun Vault)
• GP100 review (Diesel Legiance)
• GP100 review (TheFirearmGuy)
• GP100 review (pliskin54)
• GP100 review (The Gun Warehouse) – pros/cons and other notable facts “GP100 shoots MOA groups after 50k rounds”
• GP100 design and history (Survival Gear Showcase)
• GP100 review (Fin Feather Fur Outfitters)
• GP100 reputation and mythology – 2,000 rounds without cleaning or maintenance, reputedly after 200k rounds still groups tight at 25 yards (Worn Trust)
• GP100 review after ~20 years of use (The Firearm Blog)
• GP100 review (Alien Gear Holsters)

Further reading

• 357 Magnum vs 9mm: Revolver or Semi-Auto for Self-Defense? (Ammo.com)
• .357 Mag vs 9mm for bear defence (Tactical Anatomy) – TL;DR: 9mm may be fun to use but fails the bear test
• Collectors guide to buying a GP100 or other classic revolvers (Luxus Collection)

Soundtrack: Marty Robbins – “Big Iron”

Trivia: GP100 starring on screen