Hand spring modification


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JN01
January 8, 2011, 05:50 PM
One of the weak points of SA Colt revolver repros is the little leaf spring that puts tension on the hand, they can easily break off. The slot in which it fits is very narrow and tight, making replacing just the spring difficult. Fitting a new hand/spring assembly requires careful fitting so that it is timed properly, not really a skill that I possess.

I know some of the SAA repros have a coil spring which is installed in a hole drilled from the rear of the frame and held in place by the grip frame.

Anybody know of someone who could modify a '51 Navy to use a coil spring?

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rdstrain49
January 8, 2011, 06:22 PM
http://www.theopenrange.net/articles/Tuning_the_Pietta_Part_One.pdf

http://www.theopenrange.net/articles/Tuning_the_Pietta_Part_Two.pdf

this may help, if I got the right one.

J-Bar
January 8, 2011, 06:39 PM
Mr. Pettifogger is a genius, and his step by step instructions for adapting a Ruger hand spring and plunger work.

But there is another alternative.

The flat hand spring can be replaced with a piece of straight spring wire, if you have the means to drill a precisely placed hole in the hand.

Break off the factory spring, and remove the little piece of the hand that covered the base of the old spring. Drill a 1/16" hole through the hand at the point where the old spring was attached. Using a triangular file and some patience, file a groove all the way around the bottom of the hand. Insert a straight piece of spring wire, about .035" diam, give or take a few thousandths, through the hole and bend it so that it fits into the groove in the bottom of the hand. Then trim and bend the other end of the wire to approximate the shape of the old spring.

Pictures attached.

You can solder the wire to the groove if you want, but the pressure of the spring in the hand slot in the frame will usually hold it in place.

It does not take much pressure to hold the hand in the proper position. This wire can generate enough pressure to slow down the hammer drop and cause misfires, so play with it to generate just enough pressure on the hand to make it engage the ratchet.

I have had 10 1851s modified this way. None have broken yet. I learned to do it this way from Michael Allee, a wonderful gunsmith in Kansas City.

Good luck.

JN01
January 8, 2011, 07:22 PM
Great tips, just what I was looking for. That tune up tutorial is outstanding as well.

Thanks.

rdstrain49
January 8, 2011, 07:40 PM
J-Bar, that is just too simple. Mr. Allee must be a wonderful resource to have. I've got to try that. Thanks

Jim Watson
January 8, 2011, 08:14 PM
Great. I have seen Colt clones that were "Rugerized" but the wire handspring has the advantage of letting you work on the cheap part.

J-Bar
January 8, 2011, 08:21 PM
If you are going to try the wire hand spring, I suggest buying two or three replacement hands from someplace like VTI gunparts, and practice making a few on those.
Then when you are confident of your technique, you can work on the one in your gun. That way you are less likely to screw up the one that is already fitted to your gun. And if you do screw it up, you will already have spares on hand ready for final fitting.

rocky branch
January 9, 2011, 01:03 AM
Great idea using the wire!

I have a few old hands t practice on/

SixxshootinSam
January 9, 2011, 02:20 AM
I used my wife's hair clip, those cheap ones that you bend slightly and they clip into place. The metal is very strong yet springy. I cut the middle piece off and used that as my new spring, it has yet to fail on me.

mothernatureson
January 9, 2011, 02:56 PM
I have just opended up the groove on the hand, and placed in its place a small length of guitar string, bending an angle at one end, small enough to work in the slot of the frame. i cant remember if I put some jb weld on it as well. But does not take much of a spring to keep pressure on the hand to engage the cylinder. Just play with the spring , I wouldnt go to the expense of practicing on extra hand/springs. That fix was done a few years ago, and is still working fine. Good luck!

mothernatureson

Cap n Ball
January 9, 2011, 03:59 PM
My gunsmith replaces the hand spring with flattened piano wire with excellent results.

Jaymo
January 9, 2011, 04:26 PM
I like this idea. I wonder if the wire type trigger/bolt spring can be used as a replacement for the leaf type trigger/bolt spring in the 51/60 Colt and 58 Rem repros from Pietta et al.

mykeal
January 9, 2011, 05:28 PM
Yes. I've used this one to good effect in several replicas:
Heinie SA trigger/bolt wire spring (http://www.brownells.com/.aspx/cid=0/k=Heinie+spring/t=P/ksubmit=y/Products/All/search=Heinie_spring)

Noz
January 10, 2011, 10:43 AM
I do the Pettifogger mod on the hand spring. Drill the frame for a Ruger coil spring and plunger.
Again, not rocket surgery. First one I did I sweat bullets over the precision required. Then did the others in an assembly line type of operation. No sweat. I have six frames converted but I use two. I have the two frames tweaked to the nth degree and simply change barrels and or cylinders as the mood strikes.

Conversion takes about 2 minutes.

dudlee
April 14, 2011, 09:48 PM
I received the smaller Ruger spring and plunger from Brownells that is listed in the Pettifogger mod and am ready to drill the frame on my EMF 1851 Navy.

Q1:I was wondering how much of the spring is sticking out when you assemble the backstrap onto the frame?

Q2: Is it harder to get the backstrap on and keep the spring from getting pinched? My Uberti 45 colt has a set screw that keeps the spring in the frame.

Q3:The difference between the #42 drill bit recommended(.0935) and a 3/32 (.0938) bit is .0003 inch. Has anyone used a 3/32 bit? I've got lots of them but no #42 bits.

madcratebuilder
April 15, 2011, 08:26 AM
I received the smaller Ruger spring and plunger from Brownells that is listed in the Pettifogger mod and am ready to drill the frame on my EMF 1851 Navy.

Q1:I was wondering how much of the spring is sticking out when you assemble the backstrap onto the frame?

Q2: Is it harder to get the backstrap on and keep the spring from getting pinched? My Uberti 45 colt has a set screw that keeps the spring in the frame.

Q3:The difference between the #42 drill bit recommended(.0935) and a 3/32 (.0938) bit is .0003 inch. Has anyone used a 3/32 bit? I've got lots of them but no #42 bits.
#1 about a quarter to three eighth inch.
#2 yes
#3 use either size bit, .0003 makes no difference in this case.

dudlee
April 16, 2011, 06:52 PM
The Pettifogger spring and plunger mod went pretty well. I did try to make a new spring from a piece of feeler gauge but the part of the hand thats crimped over the flat spring broke off.. The Pettifogger mod should be much more reliable..
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