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velocette
May 24, 2009, 08:31 AM
I'm looking for information on how to "set" the sear spring on a MkIII BHP. I'm slowly working my way through my .40 BHP with Cylinder & Slide hammer, sear, spring kit & wide trigger. Last on the list is the sear spring. Trigger pull now is 4.75 lbs, & looking for 4#. Any suggestions?

Roger

JMBstudent
May 24, 2009, 04:28 PM
Roger,
I just finished smoothing out my HP trigger.
I noticed the C&S sear was rubbing against the frame.
I ended up reducing and polishing the sides of the sear as well as the side of the frame and ejector.
I reduced the hammer notch height to .020" and lightly polished the hamer notch sear face.
I also added a small secondary face to the sear.
Care must be taken with the hammer notch as the angle is less than 90 degrees.
The purpose of the acute angle is to trap the sear at full cock.
The geometry of the HP is not the same as a 1911.
For safety, it is important to maintain the 85/86 degree hammer notch angle. Light polishing only.
The trigger measured 3lbs 8ozs with a friends digital trigger scale.
I did not reduce the sear spring pressure.
I haven't really done any work with the sear spring or the main spring.
Maybe there is something there, I don't know.
I feel comfortable with this trigger and I would be reluctant to lighten it any further.
This from a 1911 guy with 2 1911 pistols at 2lbs 8ozs. Competition only.
I have tested my HP for hammer follow with the pistol in all positions.
It passed every test.
The trigger is clean and the break is sharp.
I'm happy, as are several people that shot the pistol.
I'm looking for a wider trigger than the stock, as that is what I prefer.
This pistol is NOT for carry. It is for target and competition work only.
I would stay closer to 5 lbs for carry.
I cannot recommend using stock parts to lighten an HP trigger as I have no experience with the stock sear and hammer.
I would suspect the hardness of stock parts.
Don't forget to double check the thumb safety after any trigger work.
Be prepared to replace the thumb safety.

velocette
May 25, 2009, 09:00 AM
JMB student;
Thanks for the information. Most of what you've suggested has been done. The sear is free of any side to side friction, I have cut a small undercut on the lower edge of the sear & deburred all corners & edges. All that is left is the sear spring that someone in the past (me) "adjusted" to cure a hammer following problem with the original hammer / sear. I just think that I went too far and I do not know where it was originally.
Incidentally, the Cylinder & Slide wide trigger is quite a bit better than the original narrow one from Browning.

Taking it out today to try to wear it out even with the 4.75# trigger pull.

Roger