Mark II one-piece vs. three-piece mainspring housings

[kean57]

Hello.

Does anyone know when Ruger switched from the three-piece mainspring housings to the one-piece (and back again)? Some time in the early '90s Ruger supposedly told Chad Hiddleson that they were going to switch entirely to one-piece cast mainspring housings...but they obviously switched back within a few years.
I recently acquired a MK II Competition Target Model (224-prefix, late 2000 production) that came with a one-piece mainspring housing...but I have other MK IIs produced earlier (223-prefix) and later (225-prefix) that have three-piece housings. I have read that the first one-piece housing were seen on production guns as early as 1992/3...but don't know when exactly this change occurred. Anyone have approximate serial number ranges for the one-piece housings? Thanks,

Jim (kean57)

 

[chet15]

kean57
The changes are described in my pocket booklet "Reference of Ruger Firearms", first full paragraph on page 36. I evidently do not have good notes on the group of 3 piece housings past the mid 211- prefix, but sounds like you've discovered a really late range of 3 piece housings.
By the way, Ruger never told us they made the change...this variety is something we discovered when the first solid housings started being seen.
Chet15

 

[SGW Gunsmith]

I've only seen the "one-piece", cast mainspring housing on the stainless steel pistol grip frames and not any pistols that were blued. Curiously though, when I do get one with the one-piece mainspring housing in a stainless Mark II pistol on my bench, it seems like they always have the two-piece bolt body. It would be interesting to get the scoop on what the heck was involved with those changes.

 

[chet15]

I've only seen the "one-piece", cast mainspring housing on the stainless steel pistol grip frames and not any pistols that were blued. Curiously though, when I do get one with the one-piece mainspring housing in a stainless Mark II pistol on my bench, it seems like they always have the two-piece bolt body. It would be interesting to get the scoop on what the heck was involved with those changes.

Ruger was just trying to save a few pennies by making a solid mainspring housing. Same goes with the two-piece bolt.
Chet15

 

[DUNTOV]

I've only seen the "one-piece", cast mainspring housing on the stainless steel pistol grip frames and not any pistols that were blued. Curiously though, when I do get one with the one-piece mainspring housing in a stainless Mark II pistol on my bench, it seems like they always have the two-piece bolt body. It would be interesting to get the scoop on what the heck was involved with those changes.

I have a 22/45 1st design one piece in blue

 

[chet15]

I've only seen the "one-piece", cast mainspring housing on the stainless steel pistol grip frames and not any pistols that were blued. Curiously though, when I do get one with the one-piece mainspring housing in a stainless Mark II pistol on my bench, it seems like they always have the two-piece bolt body. It would be interesting to get the scoop on what the heck was involved with those changes.

I have a 22/45 1st design one piece in blue

Be sure to send me a PM on the serial number and model so I can update the Reference of Ruger Firearms.
Thanks!
Chet15

 

[SGW Gunsmith]

I've only seen the "one-piece", cast mainspring housing on the stainless steel pistol grip frames and not any pistols that were blued. Curiously though, when I do get one with the one-piece mainspring housing in a stainless Mark II pistol on my bench, it seems like they always have the two-piece bolt body. It would be interesting to get the scoop on what the heck was involved with those changes.

I have a 22/45 1st design one piece in blue

Well, I'll be danged! I never even thought to look at my first year production 22/45, as I was always focusing on the steel frame pistols with the two-piece bolts and solid mainspring housing assemblies. But..............sure enough.