SP101 FRAME CHANGE?

[Bluto]

Please forgive my ignorance here. I'm about to buy a new SP101 bobbed hammer revolver. Was there a recent past change in the frame design? A guy on a local WS with one for sale suggests his is "pre change" therefore better. Thanks for all responses.

 

[rdf009]

Ruger started using some MIM (Metal Injection Molding) parts on the SP101s about a year or so ago. The new trigger for sure is MIM, but I'm not sure what else. And the lettering on the barrels of the newer SPs is laser etched instead of stamped. But other than that, there has been no "frame change". For what it's worth, I have both an older SP101 and a newer one (with MIM parts and laser etching), and haven't noticed any difference in ability to function properly.

 

[Bluto]

rdr009: Thanks for your response and info. That must be what I heard as a "change". I'm not a fan of mim parts, and I really don't like Laser etching. I'll have look for a used gun.

Jim

 

[DPris]

The firing pin retention method is also different now, retained from the rear, not the front. That involved a minor frame change.
Denis

 

[pisgah]

The original SP101 was chambered in .38 Special, and later in .357 for 125 gr. and lighter bullets only. Reason for the restriction -- the frame, therefore the cylinder, were not long enough to accommodate longer loads. The frame and cylinder were lengthened. Although there have been other minor changes through time, this was perhaps the major one.

 

[DPris]

That was several years ago, unlikely to be either the "recent" change mentioned, or any reason to believe the original .38 Special frame was superior to current SPs.

 

[pisgah]

That was several years ago, unlikely to be either the "recent" change mentioned, or any reason to believe the original .38 Special frame was superior to current SPs.

And no reason to believe the seller nwhat he's talking about, either. :wink:

 

[Bluto]

Thanks to all for info. Are not "mim" parts finished in such a manner that polishing or removing any material might soften the surface that material was removed from?

 

[pisgah]

No. MIM parts are consistent all the way through, unlike machined and hardened parts which have a thin hardened "skin" that can be filed through to softer material.

 

[Bluto]

No. MIM parts are consistent all the way through, unlike machined and hardened parts which have a thin hardened "skin" that can be filed through to softer material.

Thanks for clearing that up. I recall when Colt started to go with mim parts in their 1911's. A lot of speculation then about quality of such parts. About then I got out of 1911 collecting as it was breaking my personal bank. I carry a revolver, most often a J Frame or DS. I thought about a SP101 as the extra weight might help with recoil as I now have arthritis in both hands.
I would not shoot .357 out of it.

 

[DPris]

I'd agree with Pisgah that the seller doesn't know what he's talking about.
Indications are that the frame change involving the firing pin is actually beneficial, and I see nothing about earlier frames that makes them "better".
Denis

 

[Knuckles]

alas!... I found a frame change in the cut-out for the grip.

My uncle Mike's "boot-grip" fits a little sloppy on my newest Sp101... to the right of the pin.

Hey' ain't that a kicker?

Ruger changed the frame on the SP101's around the time the 327mags came out, thus the extra space cut from the left side.

You can tell what gun the Boot-Grips will fit by looking at the hammer.
If it sticks out from the frame it is the old model and you're golden, but if your hammer sits flush you have the new frame and you get the gap on the left.

It doesn't hurt anything but it is not a good purchase for someone like me with OCD's :wink:

Please share this info with others.

Take care, Bud (knuckles)

 

[louiethelump]

In some cases, MIM actually improves the small parts used inside auto pistols. I know the S&W 9mm police guns had a problem with the draw bars cracking until they went to a MIM part there. It allowed them to radius the insides of the corners to get away from the square corners they had by forging and broaching............ and the bars quit breaking........ They also had problems with the disconnector that was a stamped part with a pin through it, and then made of plastic. MIM allowed a one piece part made of steel that corrected that problem as well. The consistency of the MIM parts in S&W revolvers allowed them to take advantage of the more precision machining of the frames made possible by the computer driven milling machines, and the two together allowed a much closer fitted action with much less fitting making it much easier for you to change your own hammers and triggers. Not all progress is backwards.

 

[Knuckles]

+1 'lump

 

[harley]

I dont have the newer lazer etched version but I believe besides all mentioned there was one other small change. the cylender stop was removed. This is more disturbing to a traditionalist or S&W guy.

 

[mustang99]

No. MIM parts are consistent all the way through, unlike machined and hardened parts which have a thin hardened "skin" that can be filed through to softer material.

Unless I am missing something, this is well-intentioned, but incorrect advice.

Through hardened = same hardness all the way through

Case hardened = hard skin (HRc 50+), usually .008-.012" thick

These 2 heat treat methods can be used on both MIM and machined parts, depending on the material they are made from. So you can't generalize that ALL MIM parts are through hardened and ALL machined parts are case hardened. Hope this helps, and I hope I did not ruffle any feathers.