Is this normal for a GP-100 ??

G

Greg All Calibers

New member
One of my very best firearms is my beloved Ruger KGP-141 GP-100. I spent a lot of time with it, and know it well.

I have a question for all of your that have one, or know about them...

... does the back part of your cylinder (actually it's the crane), rub on the frame right below the forcing cone, when you close the cylinder?

I picture is worth a thousand words. Take a look below. Is this considered 'normal' to have this rub. I would think you would not want any clearence for a firm lock-up, but wanted to be sure.

Thanks for the feedback !

Here you can see the scratch from the crane rubbing when it's closed. All the other scratches below are from manufacturing, and they do not rub anything, so disregard them.

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It's hard to see the scratch on this side, but this is where the crane is rubbing. Is it supposed to make contact with the frame here?
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I just checked mine and there is no signs of any rubbing in that area. It is very close (estimate .001 or less), but not touching.

(Excellent technical pix, BTW.)
 
Mine's mighty close, but does not appear to have the scratch mark your photo shows. It's really difficult to tell with the machining marks left on the frame. I mine has contact, it is very, very slight.
 
I think you should forward a link to this

thread to Ruger Customer Service. Your description and photos are pretty clear.:)

That looks like the gas-check area, and I don't think it should be contacting like it is. My question is, is this a relatively recent development, or has it always been this way?
 
Oh yes! I have seen that before and you have a warped crane and you should send it back to Ruger-post haste!
There is a very,very rare possibility that your frame is bent but I doubt it. That area is very close indeed and is checked by quality control before it left the factory. That is one of the 'beauties' of Ruger in that they have excellent QC and it just would not have left in that condition.
We are talking much pressure when a 357 round is touched off and the last thing you need is a malfunction in the cylinder-cone area. That could be a stick of dynamite going off in your hand!
Don Mallard
 
Mine doesn't touch either...whew...had to jump up and look real quick.

I looked at your pictures and it appears to me that the end of your cylinder might be making that mark. It looks like it was caused by rotational action and not the opening/closing of your cylinder.

Do you have a lot of back and forth play in your cylinder? (cylinder endshake). You might have stretched your yoke.


Bob
 
Good pics. Good advice above. Try email with thread to Ruger and back it up with phone call if no response in a couple of days.

Sam
 
Mine looks just like yours. I never gave it a thought before. Mine is currently dirty and it is obvious because the rest of the area is covered with powder fouling and that area is shiny.
 
OWN TWO

Checked; both DO NOT have those marks, and both have taken some heavy loads.
One has been my primary test bed for 180g deer loads.

(Both wear Pachmayr Decelerators)
 
Spent the majority of the afternoon doing a trigger job on the gun, including the new springs (hammer and trigger from Wolff). The action is excellent. Butter smooth !

I have about 3000 rds through this gun. All factory loads, about 60% 357, and the balance 38 and 38 +P.

It's always rubbed there, when you close/open the cylinder (not when it goes around). From day one.

The cylinder does not bind in any way, remember it's the crane that is rubbing right under the forcing cone (again, only when you close/open the cylinder). And the rubbing is very slight.

I believe it's manufacturing tolerance, probably should not touch- but should not cause any issues either. But of course, will check with Ruger to be sure.

Any more input is appreciated, especially if you have a GP-100 to inspect.

By the way, anyone know how to remove the cylinder from the crane. Is it pinned in?
 
Greg . . .

1) Excellent posts, explanations, and documenting photographs. THANKS!
2) Neither of my KGP-141s exhibit this mechanical interference.
3) I agree it's likely "manufacturing tolerance buildup" -- and it may not be crucial.
4) However, I strongly endorse conferring with Ruger and having them FIX THE PROBLEM TO YOUR SATISFACTION.

Regards.
 
Confound it!! I believe I reside in the "marked" camp with Greg. I am thinkin like 444 since the contact area is shiny, and I can also see small gouges. I am going to the range tommorrow, and I will ask the smithy. Also, Sturm Ruger gets off vacation tommorrow I think, so I will also attempt to call Customer service.

Take Care,
Rhyno
 
Solved

After close measurements with a micrometer, it appears there was slightly (a few thousands) to much frame under the forcing cone that remained after they finished the gun at the factory.

I bet they start with a rough machined frame that would normally rub slightly, and then during the finishing process that area is deburred/dehorned just enough to allow clearence for the crane.

So I did it myself. Mine you, I am not into taking much metal off a pistol that handles 357 rds... so at most I removed .002", if that. At least that's what the micrometer says. I started with Aluminum Oxide and Silicon Carbide 150 grit, then 240, then 400. Then wet-sanded with 600 and then 1500 Ultra Micro Fine. The last step was to polish the area using Mothers (my favorite).

Now there is no touching or rubbing. Everything else checks out. Will take to range tomorrow.

Here are my post-finishing pictures. I performed a trigger job, and also the work above. Compare this shot of the frame to the original pictures. I closed and opened the cylinder about 50 times before the picture, no rubbing. Also polished the right side of the frame and eliminated all the machining marks.

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and a pic of the entire gun. Man, this is one sweat looking Ruger.

5temp.jpg
 
3000 rounds? It doesn't even look like the topstrap is broke in! I must commend you on your cleaning and care of that firearm, It looks better than new.

How long did it take you to do that work?

Bob
 
Bobshouse,
Thanks for the feedback. After a single rd or more is put through any of my firearms, I field strip them and perform a detailed cleaning.

Anyway, back to your question... the work took about 4 hrs for the frame adjustment because I wanted to work very carefully as to not take too much metal off, so I did it by hand (sandpaper on a pop stick). I did not even use my dremel tool (which I do use for trigger jobs). The trigger job took 3 hours (included several complete assy/dis-assy to adjust).

Here is a picture of my colt pony. It has seen about 2000 rds. I dehorned it using the same technique, but started with a file to round off the complete rear near the hammer for a confident CCW draw (summer gun, 4513TSW all other times). Gave it kinda of a SM&A job (for those with Pony's, you know what I mean!).

Happy New Year.

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