Strengthening the Uberti 1862 Police mainspring.

[OldFrenchy]

Applied this simple workaround to give my Police model a heavier mainspring to help prevent hammer blowback and cap sucking (along with hammer face dressing). I placed a small lock washer at the base of the mainspring between the frame to extend the length of compression.  It may weaken the mainspring over time, we'll see. I had read of someone doubling up on the mainspring to make it heavier, but I was unable to do that as the second mainspring rose high and I couldn't get it under the hammer roller. It significantly made the hammer cocking heavier.
I will let you know how it (or if!) It works.

[Captainkirk]

I've done that by simply installing the washer between the spring and grip frame. I've been told a thick leather washer works better as it doesn't have a sharp edge to bear against the spring

[ShotgunDave]

That should do the trick Frenchy. I've seen others do that and they report that it does indeed work.

[bigted]

I have and shoot a 2nd generation Colt 62 and it has a significant heavier mainspring.  This revolver is not a cap suckered and the action is very smooth. Had to fiddle a bit with it when new but she is a peach to shoot. Very accurate too.

I believe that you are on the right track with the washer under the spring. Bettin you fix a bunch of problems with this fix and if you switch to nipples with a smaller vent hole your cap sucking should be a thing of the past.

[OldFrenchy]

Agreed. Took the little police to the range and there is still considerable cap sucking. The nipple vents are obviously too large and blow back the hammer.
I am in search of replacement nipples with small vents.

[G Dog]

You're experienced and been at that Police for awhile, Frenchy.  I understand that but I'm thinking this may not be a flash channel diameter problem.  I'm thinking main spring tension.  Even after your fix you may not have enough.  I've used the leather washer fix and torqued the main spring screw down blood-tight on one of my Colts and it fully solved a blow back issue.  You may have accurately diagnosed this, though. 

What's the tension like when you cock the piece?

Not second guessing you here, bud.  Just sayin.

[45 Dragoon]

Ok, normally, putting a leather  or steel "spacer" under the spring will lighten the spring tension not increase it. Leather isn't good because it dries out, cracks, rots .  .   . same with rubber, cork  .  .  .   the best of the spacers is good ol steel.  The "pliable" spacers (the bad ones) effectively allow some cushion to effectively minimize the contact area of the bolster (mounting surface). The small steel washer actually becomes the bolster and since it has a small area, allows more flex for the spring.   I say all this but by no means mean to step on any toes. I also realize this isn't what the OP was intending to do.

So, what the op could do is put a bit of an upward bend at the end of the spring under the hammer roll. This will increase the tension applied as well as increase the hammer speed. I call it (affectionately lol!!) Goons "kickass main spring"!! 
 If that doesn't provide enough tension, you can use a feeler gauge leaf, narrowed to fit under 1/2 to 3/4 the length of the spring  plus, they already have a hole for mounting!!. The leaf will act as a helper spring much like on a solid axle auto  leaf spring setup. This method works well and is in at least one pair of state championship revolvers.
  I'm afraid the position of the lock washer as pictured in the op's revolver will definitely weaken the main.

Mike

[Zulch]

You're experienced and been at that Police for awhile, Frenchy.  I understand that but I'm thinking this may not be a flash channel diameter problem.  I'm thinking main spring tension.  Even after your fix you may not have enough.  I've used the leather washer fix and torqued the main spring screw down blood-tight on one of my Colts and it fully solved a blow back issue.  You may have accurately diagnosed this, though. 

What's the tension like when you cock the piece?

Not second guessing you here, bud.  Just sayin.

G Dog. Which smaller vent hole cones would you recommend as a fix for cap sucking? Thanks Tim

[G Dog]

Thanks again, Mike.  You provide the best information available anywhere.  I've saved some of your posts over the years and refer to them regularly.  Taken together, your posts are more informative than any book ever published on the subject. Please keep them coming.  (You also have the modesty and demeanor of the true professional.  I know you don't want to hear that but I'm sayin it anyway.)

Some time ago, without being very sure of what I was doing, I did "bend" the top part of the main spring upward on a Remington. Like you mentioned in your post above.  That worked real well and has given good firm hammer strikes ever since.

***

Mr. Zulch -  I'm afraid that I have no suggestions.  I have always found that stock Pietta cones work well for me.  I guess it's just dumb luck in the Great Pietta Crapshoot. Long ago I got a six pack of Pietta replacement nipples and have only used one of them. One cone on an Pietta 1997 '61 sort of mushroomed and would not take a cap but the replacement has worked fine for years now.

I've not used them but lots and lots of experienced long time shooters swear by SliXshot.

Thanks again, guys.     

[45 Dragoon]

G Dog, thank you so much for the kind words!!
  I first did the "kickass main spring"  on a Remington because after lightening the main, it didn't have enough tension to stay in the safety notch!! The hammer was basically Out Of Gas at rest!!! I was like HOLY COW!!   Then it dawned on me that if I moved the end of the spring higher, it would have tension!  Voila!!!! I've been doing that across the board for years now (except for ROA's of course).

 A by-product of this little mod is you get an acceleration of the hammer at the end of travel (the "kick in the ass so to speak!!). This was realized with comparing this mod and a Walker /Dragoon V main spring. The way that spring rides in the semi circle  cup in the hammer, the geometry of it accelerates the hammer at the end of travel .  .  .  a rather ingenious design even if unintended ...!!

Mike

[Navy Six]

So, what the op could do is put a bit of an upward bend at the end of the spring under the hammer roll. This will increase the tension applied as well as increase the hammer speed. I call it (affectionately lol!!) Goons "kickass main spring"!!

Thanks for the suggestion of bending the mainspring tip upward under the hammer roll. Is it necessary to heat that area before bending? I noticed both my Uberti Pocket models exhibit the same characteristic--when initially pulling the hammer back the mainspring feels extremely light. Once passed that point of rearward hammer travel the mainspring tension feels sufficiently strong. I wonder if that initial weak spot is the source of the hammer blowback problem. Either way Mike I would like to try your idea of bending the mainspring as I am determined to get passed that annoying blowback problem on the Pocket Models. 

[45 Dragoon]

Hey, no heat needed. Not much of a bend. I'll try and post a pic.

Mike

[Navy Six]

Thanks Mike, a picture would be a great help!