burgerdude

Does anyone know what the current production sp101 .22 mainspring is rated?

laidlerj

As far as I know, the hammer spring for the SP101 is the same regardless of caliber - 14 lbs. It's the same spring as in the GP100 and (surprise!) the Super Redhawk. I found this last out when I replaced my SP101's hammer spring.

Jim

Sal1950

I don't know what the spring is rated at but be aware that it does have a different part # than the mainspring for all the other SP101 calibers. I suspect it may be a little heavier to lite rimfires but can't prove it.
But theres a reason they have a different part #?
Sal

KJS

Do .22 revolvers generally have especially heavy springs to smack the hell out of rimfire cartridges to ensure they go "bang"?

I ask because my S&W 617 has a notably heavier trigger pull than my GP100, and the GP has yet to find a primer it couldn't set off on the first strike after thousands of hits.

Sal1950

That is my experience and understanding, yes.
If you witness the posts here on the release of the new SP101 22lr-8, the number one complain was about the heavy trigger pull..

If you compare the tests made by Jeff Quinn at Gun Blast of the last 3 latest SP101s released, the DA pull measured,
SP101 327 = 9lb 6oz The New .327 Federal Magnum in Ruger’s SP101 Compact Six-Shot Revolver
SP101 4.2" 357 = 9lb 9oz Ruger Four-Inch 357 Magnum SP101 Double-Action Kit Gun
SP101 22-8 = 11lb 4oz Ruger Eight-Shot 22 Long Rifle SP101: Stainless Steel Kit Gun Perfection

So there's a reason Ruger put a different mainspring (it does have a different part #, KW00403 in the 22 as compared to KW00401 in all other SP101s).
I'm sure it wasn't just to p-ss customers off. LOL.
Sal

UPDATE TO Wolffs site,
RUGER SP-101 REVOLVER
Important Note:
Due to changes in this gun by the manufacturer, the spring below will not function in SP101 .22 caliber rimfire models manufactured during and after 2011.

laidlerj

I checked the Ruger website and my owner's manual - both agree that there is only one mainspring for all SP101 models - part # KW00401. Where did you find different part numbers?

Jim

Sal1950

Interesting, there was an addendum listed there when I wrote that and I got a hard copy with the documentation for my new 4" 357 SP101. Don't know why the addendum has disappeared from the site. They didn't update full manual yet either, witness there being none of the other 22 specific parts, like a 8 shot 22 cylinder.

INSTRUCTION MANUAL INSERT FOR
RUGER® SP101®
8-SHOT ~ .22 LONG RIFLE CALIBER
NOTE: With the exception of its capacity and caliber, the 8-shot RUGER® SP101®
has the same basic operational characteristics as all other SP101 revolvers. Please refer
to page 11 in the instruction manual for Ammunition information. Other features of
this revolver include a Hi-Viz® front sight, and adjustable rear sight.
AMMUNITION
Rimfire ammunition manufacturers use different types of brass for their cases and different
lubricants on their bullets. As a result of these variations, some rimfire ammunition
can cause extraction issues in double-action revolvers. If a particular type of
rimfire ammunition is causing extraction problems, then first clean the gun in accordance
with the instruction manual (see p. 22). If extraction issues persist, then try
another brand or type of rimfire ammunition.
ADJUSTABLE REAR SIGHT
NOTE: Each click of the rear sight adjustment screws (either windage or elevation)
will move the point of impact of the bullet approximately 3/4” at a distance of 25
yards. Move the rear sight in the direction you desire the bullet to move on the target.
RIGHT
LLEEFFTT
RIGHT
To raise point of impact: turn screw counterclockwise.
To lower point of impact: turn screw clockwise.
To move the point of impact to the right:
turn screw counterclockwise.
To move the point of impact to the left:
turn screw clockwise.
UUPP DDOWNN
ELEVATION WINDAGE
7/11
SUPPLEMENTAL PARTS LIST
Key Part Name Part No. Model
† 1 Frame KW00216 KSP-242-8
* 2 Cylinder, 8-shot KW00133 KSP-242-8
* 3 Ejector KW01823 KSP-242-8
* 4 Barrel KW00643 KSP-242-8
5 Rear Sight Elevation Screw W05911 KSP-242-8
6 Rear Sight Blade W05917 KSP-242-8
7 Transfer Bar KW01703 KSP-242-8
8 Rear Sight Cross Pin KW05913 KSP-242-8
9 Rear Sight Elevation Spring KW05914 KSP-242-8
10 Rear Sight Windage Spring KW05915 KSP-242-8
11 Front Sight, HiViz® W03610 KSP-242-8
12 Grip Panel Insert, Left W01030L KSP-242-8
13 Grip Panel Insert, Right W01030R KSP-242-8
14 Rear Sight Base W15900 KSP-242-8
15 Rear Sight Windage Screw W05912 KSP-242-8
16 Grip Panel Screw KW01300 KSP-242-8
* 17 Firing Pin KW02112 KSP-242-8
18 Mainspring KW00403 KSP-242-8
† The frame is a serial-numbered part and is not offered for sale.
* Parts so marked must be factory fitted.
1

laidlerj

Sal1950,

Curiouser and curiouser...

I went to the Ruger website today - just now, in fact - and the SP101 manual (see: https://ruger-docs.s3.amazonaws.com/_manuals/sp101.pdf) lists several parts specific to the .22 LR model (barrel, cylinder, firing pin, pawl, sight parts, recoil plate, etc.) but NOT a different mainspring.

Is it possible that some models had a different mainspring but that Ruger found there wasn't sufficient difference between them in function to warrant stocking two different parts?

At any rate, it looks as though someone wanting to replace the mainspring on a .22 LR SP101 could use 14 pounds as a reference for the "factory" rating and go from there.

Jim

Sal1950

The 22lr specific parts you see in that 3-2009 dated owners manual are for the old original SP 22lr. Notice the cylinder listed for it is a 6 shot? Notice the cylinder listed in the supplement I posted (dated 7-11) is a 8 SHOT
Take the info in that 7-11 supplement as the facts, the one on Rugers site is obsolete.
Sal

laidlerj

I'm not doubting you, Sal, it's just that I didn't immediately notice that the date on the information you posted was "7/11" (it's kinda buried). Of course, since it's newer, then it's more up-to-date than what is on the Ruger website today.

Still, do you have any idea if the new mainspring (KW000403) is different in any way from the old mainspring (KW000401) that was ALSO used in .22 LR revolvers (albeit with only 6 shots rather than 8)? Is it a different strength or a different length? Unless there is some significant difference in the trigger/hammer configuration of the 8-shot .22 LR SP101, I can't see that there would need to be any difference in spring strength.

Of course, I am always open to the very real possibility that I am wrong. It may be that Ruger belatedly decided that the .22 LR needed a different spring weight. My SP101 is in .357 Mag and I've never owned one in .22 LR - were there problems with ignition or peening of the rimfire firing pin that would prompt a change in spring strength?

I'm not questioning your expertise - just asking questions.

Jim

Sal1950

Not a clue Jim, can only surmise there must be some reason for the specific part #.
I doubt you'd get any info out of Ruger on the question.
If you'd really like to know you might try a polite email to Wolff springs. They definitely are aware of something going as as witness the IN RED warning on their website about the 22-8 mainspring.
Springs for RUGER SP-101 Revolvers
Maybe they'll tell you what Ruger changed in the mainspring on the SP101 22-8
Sal

paochow

I installed the stock 14# spring from my SP101 357 in my Sp101 .22lr and the DA pull weight dropped about 14oz, so I'm thinking the.22lr spring is heavier. I ended up sticking with the 14# spring as it doesn't give the occasional light strikes I had with the 12# wolff.

Sal1950

That is my suspicion also, that they are a little heavier than then std SP101 mainspring.
Sal