Milsurp Hi Power hammer moves a little at start of trigger pull

[IMtheNRA]

I have one of the Israeli surplus FN Hi Powers that were on the market about ten years ago. Today, I noticed that the hammer moves like it "tries to fall" just a fraction of a millimeter at the beginning of my trigger pull. It is just a tiny movement that stops abruptly.

As I proceed with the trigger pull, the gun fires as expected.

In the past ten years, I removed the trigger disconnect, and installed a slightly softer hammer spring, but I don't have the notes with me to look up the exact weight of the new hammer spring at the moment.

What do you think is causing this movement of the hammer, and is it a sign of something wearing out inside this nice old Hi Power?

 

[Mizar]

Your hammer's full cock notch is either worn or cut at an incorrect angle. It will get worse to the point when the hammer will not stay cocked.

Boris

 

[IMtheNRA]

Boris, thank you for your insight. Since this is an educational opportunity for me, would you mind telling me what is going on with the faulty hammer's notch to cause this motion?

Is a new hammer a drop-in replacement part or does one expect to have to fit it to the gun?

 

[jonnyc]

It is usually a good idea to install a "matching" hammer and sear, and fit them together.

 

[rellascout]

It sounds like the hammer sear engagement is worn. This can happen with age. I would recommend getting a hammer and sear set from MidwayUSA. I like the C&S parts. IIRC they sell a matched kit.

 

[Mizar]

+1 to jonnyc. And may I add: by a competent gunsmith. The top angle of the full cock notch (the lower one on the hammer) gets rounded from the sear rubbing in it and wearing it off. This condition leads to hammer follow, but how soon it depends from material hardness, depth of the notch, condition of the sear and etc... Before you buy a new (and expensive) hammer and sear set do consult with a gunsmith - he may be able to re-cut safely the existing hammer.

Boris

 

[rellascout]

+1 to jonnyc. And may I add: by a competent gunsmith. The top angle of the full cock notch (the lower one on the hammer) gets rounded from the sear rubbing in it and wearing it off. This condition leads to hammer follow, but how soon it depends from material hardness, depth of the notch, condition of the sear and etc... Before you buy a new (and expensive) hammer and sear set do consult with a gunsmith - he may be able to re-cut safely the existing hammer.

A C&S hammer and sear set will cost you $119 and if you can detail strip the BHP you can instal it. A smith is going to cost you almost as much to "fix" the old parts.

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=273608

 

[Mizar]

rellascout, when I give advise to someone I don't know I prefer to be on the safe side. Seen my share of butchered simple DIY jobs.

Boris

P.S. Isn't 100$ for a simple re-cutting of a hammer notch too much?

 

[rellascout]

rellascout, when I give advise to someone I don't know I prefer to be on the safe side. Seen my share of butchered simple DIY jobs.

Boris

P.S. Isn't 100$ for a simple re-cutting of a hammer notch too much?

Again in general a match C&S set is a drop in. If you can detail strip your BHP you can instal them. I understand the caution but in the end the C&S parts are a major improvement IMHO over the stock parts so the $100 not an even swap. Every BHP I have installed C&S parts into had an improved trigger pull after the instal. I have done them myself and had gunsmiths do it as well. I will admit the one done for me by Wild West Guns was better than my instal. LOL

I have never had someone re-cut a hammer and sear for me but most smiths in my area will charge you $50 to look at a pistol. LOL

 

[IMtheNRA]

Thanks a lot to all of you! I think I'll take this as an opportunity to improve the awful trigger pull a bit and order the C&S parts. I feel very comfortable installing the parts, provided they don't need any fitting or stoning. I've had taken another HP apart into all of it's component parts just to see what's what and I had no trouble putting it together. Had only a handful of parts left over

I"m OK with parts swapping; gunsmithing - not so much.

 

[The Lone Haranguer]

That is called "hammer camming" and is common for the CZ75, but it is not normal for BHPs.

 

[Mizar]

On a CZ 75 the hammer is moving in the opposite direction - towards shooter.

Boris

 

[velocette]

+1 for the Cylinder & Slide hammer & sear. They are well made and fit properly. Stock BHP hammer & sear are not as hard nor as well cut as the C&S parts.
The only difficulty in installing the sear yourself is dealing with the sear spring as you install the sear pin. A little patience works nicely.
Rellascout knows his BHPs very well and his advice good.

Roger