Hammer Follow on 10mm Witness Hunter

[Reverendpdp]

I recently replaced the recoil spring to a 20#,  added a shock buffer and replaced the hammer spring with an extra power one, all hoping to slow down the reward recoil.  When I tested the gun this way it ran fine.  Then I added an optic (Deltapoint), and now the hammer falls when I hit the slide release or sling shot the slide.  Doesn't make sense I know.  Thinking that maybe it was the heavy hammer spring, I went back and reinstalled the stock HS.  BUT the hammer is still falling.  Any suggestions?  I'm not too mechanical but can follow videos to take the gun apart and put back together.  TIA

Edited February 22 by Reverendpdp

[DesertTortoise]

Just a guess but I wonder if the extra mass from the red dot combine with the extra energy from the heavy recoil spring is jolting the hammer off of the sear. 

 

You could maybe put in a new sear spring and trigger return spring and see what happens.

[HesedTech]

Did you mill the slide for the optic? I’m not familiar with the Hunter, but all the rest have of the Tanfo large and small frames have a firing pin block. If you mill the slide the FPB has to be reduced in size. This could be your problem. 
 

To find out, remove the FPB and see if the issue goes away. 

[Reverendpdp]

Yes, the slide was milled for the optic. And yes I experimented by removing the firing pin block, and the problem was resolved. But now I have a slide without an FPB and do not know what to do next.

[HesedTech]

12 hours ago, Reverendpdp said:

But now I have a slide without an FPB and do not know what to do next.

You have two choices, do the work to the FPB yourself or send it out.

Patriot Defense will cut down your FPB, Tanfoglio | Firing Pin Safety Bock - Modified - Patriot Defense

Basically, it has to be cut shorter to compensate for the slide material milled off. You keep the same FPB spring.

 

If you are nervous call PD and ask them.

[Reverendpdp]

1 hour ago, HesedTech said:

You have two choices, do the work to the FPB yourself or send it out.

Patriot Defense will cut down your FPB, Tanfoglio | Firing Pin Safety Bock - Modified - Patriot Defense

Basically, it has to be cut shorter to compensate for the slide material milled off. You keep the same FPB spring.

 

If you are nervous call PD and ask them.

Hmmm.  Patriot Defense milled the slide.  I guess cutting the FPB is not assumed.  The funny thing is that the gun ran fine before, but once I put the optic on, the problems started.  I find it weird.  

Is the cutting down of the FPB relatively easy?  I have files and a dremel. lol.

[HesedTech]

9 hours ago, Reverendpdp said:

.  I find it weird.  

Is the cutting down of the FPB relatively easy?  I have files and a dremel. lol.

I have had PD do several slides for me and unless you send the whole gun to them or ask they assume the owner knows enough.

 

As far as you doing the work, it’s basically filing down the part that goes against the optic until it fits and runs in the gun. If you cut too much off buy a new one. I do believe the FPB is hardened so it may take some work. 
 

Good luck and have some fun.