1872 Open Tops help needed

[Doc O]

Howdy
  Just picked up my second set of 72's, 45 schofield from cimarron. They shoot great but think I'll replace the firing pins with some from the smith shop. What I need to know is, after installing the new pins will I need to open up the flash holes? If so, what is the best and/or easiest way to do so? Is this something I can do myself with simple shop tools? Any and all help welcome. Thanks Doc O

[River City John]

When I had my firing pin on my OT changed out they did not have to open the pin hole through the frame. They did heat treat the tip of the firing pin so that it would be harder and not mushroom like the original part did.

I believe the part came from VTI, but not sure.

I guess try it and check the fit first. A small jeweler's rattail should be all it takes to gently open up the hole.

[Pettifogger]

I put in some Smith Shop pins in mine a few weeks ago.  One went right in.  The other was holding the hammer back just a tad.  After checking and double checking where it was hitting, I used a small round jewelers file to open it up just a tad.  Shot them last week with BP.  They are in .44 Russian and worked fine.

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[Doc O]

Thanks for the replys.
   Another question is I'm getting some flatening of the primers with the factory pins. The factory pins are percing the primers so could this be the cause of flatened primers? I'm shooting APP under a 200gr bullet. I shoot this same load in my 75 Remingtons with no problem. Doc O

[Grouchy Spike]

Doc, the stock firing pins were a headache for me.  A pair of Open Tops would  pierce the primers, develop high primers after firing, and on one of the sixguns the cylinder would jam because of high primers. The problem was worse with 125 gr cowboy loads, less so or not so with other manufacturers.  Polishing chambers didn't help.

I sent the pair to Alan Harton in Houston who installed the Smith Shop firing pins after some polishing and shaping, and the problem went away.  Alan also did a complete action job on the pair including rebuilding the hammer cam, hardening it, trigger job, polishing and hardening the hand, opening up the rear sight notch, installing new front sight with parallel sides and serrated backside.

The Open Tops are completely new pistols.  They shoot everything without a problem including lightly loaded 38 Short Colts with 93 gr bullets, and all the ammo that had primer problems before the action job.  Smooootttthhhhhh!

A second pair of Open Tops with serial numbers about 10 less than this first pair WOULD shoot all of my ammo but with occasional pierced primers, but no high primers.  But they felt like they are filled with gravel when cocking.  This pair is now with Alan for the same treatment including Smith Shop firing pins.

Stock firing pins were the cause of the primer problems, Smith Shop firing pins were a solution.

[Major 2]

So I have decided to change out my OEM firing pin, and order one from the Smith Shop ... what is the tool I need to do the swap ?
A drift pin punch I assume but what size to I get ?
From Brownells ?

[Doc O]

Got new pins from the smith shop, had to open the pin hole just a little and they work much better. Also went to CCI primers rather than feds. Guest I'll use the original pins for thumb tacks.
          Major 2; I didn't have the corect punch on hand so I broke off the end of the right size drill bit, worked fine. Doc O

[litl rooster]

Thanks for the replys.
   Another question is I'm getting some flatening of the primers with the factory pins. The factory pins are percing the primers so could this be the cause of flatened primers? I'm shooting APP under a 200gr bullet. I shoot this same load in my 75 Remingtons with no problem. Doc O

  Mine were piercing also I took a file across the tips of the firing pins.  Just a minut amount., maybe 3 licks.  The piercing stopped.

[Flint]

Shortening, as Doc O did works, I shortened/blunted mine with an Arkansas stone and stopped the piecing.  The factory firing pin is too long and too sharp.  The only problem shortening can give is in a case of excessive headspace or endshake, or firing pin protrusion too short.  The minimum foe a Colt SAA is .046, max about .056 protrusion.