One of the peculiarities of the 1911 sear you have to consider is its curve. As stock is removed from its sear surface to effect a 'trigger job', the sear leaf spring rotates the top of the sear further to the rear, and the safety engagement surface on the other side of the sear axle pin is rotated forward. This movement of the sear safety engagement surface forward will eventually create open space between the thumb safety's sear prop surface and the sear safety engagement surface when the safety is engaged. Thus, the safety could be within dimensional specification, but allow this kind of partial sear release.
Took it apart again today to check how everything was setup and to further examine the hammer/sear. Added some images, to my untrained eye, it looks as though someone may have tried to smooth down the hammer and/or sear (although it could also be really worn down as well).
Great photos.
Your hammer is most of the problem. Its sear surfaces are on two different elevation planes. Only the starboard hammer sear surface is actually bearing on the corresponding sear surface. You can see this from the contact pattern on the sear. Someone has polished/ground it as well, but it isn't really possible to determine whether this was an attempt to correct poor manufacture or whether this polishing caused the dimensional error. Regardless, this greatly increases contact stresses on both the hammer and sear, and creates a binding torque around the pistol's x-axis as well.
Someone has also polished/ground the sear. Note the bright spot on the flat between your fingers in the third (lowest) photo. Again, it isn't really possible to determine whether this was an attempt to correct poor manufacture or whether this polishing caused a dimensional error(s). The distance from the sear hole centerline to the sear surface (specified 0.4045 -.0030 inch) also appears to be short, but this can only be determined for certain with a shadowgraph.
You should replace the hammer and the sear. Bob Serva at Fusion Firearms offers excellent quality hammers and sears which would be appropriate for a MIL-SPEC style 1911:
https://www.fusionfirearms.com/sear-black
https://www.fusionfirearms.com/mil-spec-hammer-black
There are many other good sources for quality versions of these parts, but most have race gun or Commander styling which would change the appearance of your pistol. Then again, many people like those styles......
Agree, The Hammer is worn right at the first corner is not square to the sear face... Now if your going to replace the Hammer you can get a Match sear that has a 20 Deg cut on the sear face. https://www.brownells.com/handgun-pa...prod41848.aspx
(Hammer) https://www.gunpartscorp.com/products/1635460
NRA Life member, NRARSO, Howell Gun Club member, MDFI Alum 2019 & 2020, 2023 GOA Life Member. MGO life member.
Was considering the Harrison parts actually....https://shop.harrisoncustom.com/hd-1...o-ignition-set
I know they're a bit pricier than other parts but I've used them in other 1911s before (and this one, the trigger is actually a Harrison) and they make some fine parts.
It looks like it has been Bubbatised.
Teachers leave them kids alone
Hey! teacher! leave us kids alone!
If you get Harrison's 0.4045 inch 'True Radius' sear, tell us how it works out. Interesting variation on the traditional sear engagement surface designs.
You should always determine sear engagement pattern with Prussian blue when you install a new fire control group, regardless of how well made. Tells you whether you have frame hole alignment issues.
P.S. - Nothing in your photos suggests a frame hole alignment issue of any kind, but always check.
Last edited by 10x25mm; 08-28-2018 at 10:59 AM.