Need your help again Tuner...hammer follow

[Malikovski]

Well a few months and a few trips to the range and my 1911 is acting up again.

I bought a Springfield GI model new, and it had a nasty catch in the trigger pull.

1911 Tuner graciously walked me through the diagnosis and resolution of the problem over on the m1911 forums (original thread is here). Everything was great and the pistol passed all the safety checks.

Then a couple weeks ago I was as the range and the hammer started falling to half-cock occasionally. Sure enough, it no longer passes the same checks. Cocking the pistol and applying pressure to the hammer causes it to slip off the sear and fall to half cock.

DOH!

Well I tore it apart again, and even though the hammer and sear did not have any new visible wear on them, clearly a few hundred rounds had smoothed the surfaces enough that the hammer hooks no longer reliably hold the sear. Assembling the hammer and sear on the outside of the frame, it looked like the hooks might be a little short. I figure I will replace the hammer and sear at some point, so no harm in my monkeying with the parts to try and fix the problem and maybe learn something in the process. Being careful not to change the 90 degree angle, I deepened the hammer hooks slightly.

The hammer now will not fall with direct pressure, BUT, if I rock it from side to side slightly as I apply pressure, it will still drop to half cock.

Looking closely at the hammer/sear contact, I suspect that the surfaces are not mating flat, such that the sear is making contact with the hammer hooks along a line rather than a flat surface. It's close, but that's my suspicion at this point.

Whether I get a new hammer/sear set or keep monkeying with this one, I am going to need to get them mating properly if this is going to be reliable enough for carry.

Can I do this without shelling out $200 for a jig set (e.g. here)?

Edited to add:

Forgot to mention what has been done to the pistol. All parts are original except a new 16 lb. recoil spring and an EGW firing pin stop (buggered one up, but the second one fits). A few surfaces have been lightly polished (no dremels involved), but I came to the conclusion that the pistol should work without having the polish everything to a mirror shine and left it mostly alone, except for the trigger work done in the thread linked above. It has only had about 300 rounds though it and the hammer follow really caught me by surprise.

 

[1911Tuner]

Half-Cocked

Lock the slide back...pull the trigger and hold it...and release the slide at full speed. If the hammer doesn't follow, increase the tension on the center leg of the sear spring. Adding a little on the left leg probably wouldn't hurt anything either...but try the center leg first.

If the hammer does follow with the trigger pulled, You've probably got a hammer hook to sear interface problem. Not highly likely that the hooks would wear that quickly, though anything is possible with MIM. Seen it go both ways.

Cutting the hooks deeper into the hammer didn't likely do any good. The sear rotates. Rotating it farther into the hammer means that the hooks don't sit squarely on the primary angle any more, if they did to begin with. All you accomplished was to give the sear more room to move before it gets away from the hammer hooks.

 

[Malikovski]

Hmm...yes, the sear does rotate. I try to think before I file, but it doesn't always work!

Actually I didn't realize how the angles of the hammer hooks and sear interact until I read the thread here about how the 1911 safety works, which showed very clearly how the sear and hammer engage. Then I went back and examined those surfaces, so it was probably my monkeying that caused that problem.

At this point, the hammer is not following (did the test you describe and it passes for now). Pushing on the hammer also doesn't budge it, unless I also wiggle it.

What next? Another few hundred rounds and see what happens?

Any idea what would have happened to quickly? The hammer/sear surfaces did not look at all worn...in fact they still had some parkerization left on them. Surely the leaf spring wouldn't degrade that fast...

 

[RogersPrecision]

The fact that you could 'push off' the hammer is quite significant. You also say it will still 'push off' if you wiggle it side to side.
Something is definitely wrong.
Careful, careful, careful.
I think you might be close to a dangerous situation.

 

[Malikovski]

Yes, I quit shooting it as soon as it failed the push-off test, and won't try it again until I confident the problem is resolved.

A picture is worth many, many words written by a novice, so here's what the hammer/sear look like now:

I'm hardly one to judge, but it doesn't look quite "right" to me, especially comparing to the very clear pictures in the safety thread (here). That looks solid while mine looks somehow precarious.

At present, it will not push off as long as pressure straight forward is applied. However if I wiggle the hammer side to side, it will. I assume it twists enough to rock one of the hammer hooks onto the secondary angle on the sear and that's enough for it to slide off. No one ever told me to rock the hammer side to side while applying forward pressure to see if it will push off, so maybe I'm doing something that just won't happen during firing when I test it that way.

 

[Malikovski]

PS I should probably mention I am just as interested in learning and gaining skills as fixing the problem.

I would rather spend hours reading manuals, spend a few hundred dollars on jigs and parts, and go through half a dozen hammers and sears for practice, if in the process I acquire the skills to do this sort of work, then throw in some drop-in parts and fix it in 15 minutes.

I love working on guns as much as shooting them...

 

[RogersPrecision]

In that case......
My best advice would be:
Get a machinist/gunsmith to mill your hammer hooks to .022" height, dead on perpendicular to the floor.
Obtain a sear jig and set it to a stock Colt sear angle.
This will provide a solid foundation for the further necessary work.

 

[Malikovski]

No, no, no...if I send it off to a smith, I'll never be the smith.

Surely people cut hammer hooks without milling machines. What's the preferred hand tool for this?

 

[RogersPrecision]

"Surely people cut hammer hooks without milling machines. What's the preferred hand tool for this?"


Darned if I know.
I've heard tell of hammer fixtures. My guess is the results will be less than perfect.
Wilson hammers have very nice .021" square hooks. Of course they are commander configuration and non-compatible with a gov't grip safety.
Good luck.

 

[Old Fuff]

Surely people cut hammer hooks without milling machines. What's the preferred hand tool for this?

Files and stones, and I have a box full of ruined hammers and sears that were removed from other folk's guns because someone thought that they knew it all. Bro. Rogers, who does this sort of thing to make a living, gave you some very good advice, but it wasn't the answer you were looking for.

Anyway you aren't the first to bring the subject up, and a lot of time and effort can be saved if you go to the link shown below. I suspect you'll soon learn more then you ever wanted to know.

http://www.thehighroad.org/showthread.php?t=132013

 

[1911Tuner]

Hammer

I'm still tryin' to wrap my head around bein' able to make the hammer fall by "wiggling" it. Is that a straight side-to-side wiggle...or do you twist it while you wiggle? How much wiggle room is there between the hammer and frame? Odd situation...

On your pictures...My failing eyes seem to detect a little angle agreement problem...from the gap in the corner between the back of the sear nose and the corner formed by the hooks and the floor. Hard to say from here. The hammer hooks themselves look to be a little rounded on the ends, which...if they are...could be a major player in letting them slip off the sear.

 

[Malikovski]

"Is that a straight side-to-side wiggle...or do you twist it while you wiggle? How much wiggle room is there between the hammer and frame? Odd situation..."

I'll try and describe it better. If I hold the pistol as though I were going to fire it, cock the hammer, and then pull up on the spur with my left thumb, it does not fall (it did fall to half cock at the range but not after some ill-advised monkeying trying to make the hammer hooks deeper). This is the normal "push off" test as far as I know.

Now, if I hold the pistol in the same manner, pointed away from me, apply the same pressure, but at the same time pull the hammer left and then right, maintaining the forward pressure, it does fall off the sear. I assume it moves enough that one of the hammer hooks slips off the sear. I don't know why I did this test...I think I was just trying to fuss with it different ways to see if it would malfunction. I don't know if this is applicable at all to what happens during firing.

The hammer moves side to side quite a bit, and a 0.015" feeler gauge will fit between the hammer and the frame. Normal, or more than should be?

Btw, I was not intending to scorn good advice from Brother Rodgers, or anyone else, only inquring if there was something I could do with resources on hand.

It sounds like not, and that some new parts are in order, and then most likely a jig.

Any recommendations on parts that will work on a GI style pistol would be appreicated...preferrably not too pricey as I'm sure I will not be getting it right on the first try.

 

[1911Tuner]

Suggestions

At this point, I'd say that you're in the market for a new hammer and sear. Might as well go for the disconnect and sear spring too. They're cheap compared to reconstructive foot surgery.

I do believe that EGW offers a nice spur-type hammer...Call George and ask him. That's Evolution Gun Works. Find'em on the web.

 

[Malikovski]

"At this point, I'd say that you're in the market for a new hammer and sear. Might as well go for the disconnect and sear spring too. They're cheap compared to reconstructive foot surgery."

New parts are indeed in order. I did a high res scan of the parts and your old eyes must still be working fine...there is a slight rounding on the ends of the hammer hooks and the angle is pretty clearly a touch greater than 90 degrees. I take it both of those will contribute to an unsafe situation and a tendency of the sear to slip off when it shouldn't.

I know EGW. There are no spur hammers on their web page but I'll call and see. Would you replace anything else as long as I'm monkeying? I figure I will do hammer, sear, hammer strut, disconnect, sear spring, and new pins. I think that will clean all the MIM out of the gun. Not looking for anything fancy here, just 100% reliable, safe, carry piece with a 5 lb. trigger.

Many thanks for your assistance again. I don't know anyone in person I can go to with questions. I'd be lost without forums like this and people willing to help...

 

[SACOLT]

Berryhill custom guns carries a tool steel spur hammer. You can take a look for yourself here.
http://www.berryhillguns.com/

Look at the parts section.

 

[1911Tuner]

Berryhill

Wow! Nice hammers! I wonder if they're original spec, or if the hooks and half-cock notch have been rotated...

I gotta call Dave!

 

[SACOLT]

Tuner, they're not to pricey either. right around thirty bucks.

 

[1911Tuner]

Pricey

SAColt wrote:

> Right around thirty bucks.<
************

For a machined, wide-spur hammer???

 

[Malikovski]

Wow...much nicer looking than the spur hammer that came with my pistol. I think I can check one item off the shopping list...

 

[SACOLT]

Tuner, that's what his web sight says.
https://www.berryhillguns.com/secure/parts1.html

 

[Dave Berryhill]

Thanks for the heads-up on this thread John. To answer your question, those wide spur hammers are made from a casting. The quality is excellent and if you ever manage to break one, I'll replace it. I don't know of anyone who makes a wide spur hammer out of bar stock. They would be expensive because you'd need to start out with a piece of steel the width of the spur and machine a lot of material away on the sides.

If you like that hammer, I've got a new one on the way that's even better. It's a narrow spur hammer that is EDM and CNC machined from bar stock. It's made by the same company that makes the ignition parts for C&S. It's comparable to the Tactical and Tactical II hammer (as is the "Ultimate" commander hammer that I sell) except it will have a narrow spur with serrations similar to the factory Colt spur hammer. I'll also have a Commander ring hammer made with the same specs. I'm hoping to have these later this week.

I prep the wide spur hammers using a mill like Chuck mentioned. The Ultimate commander hammer, as well as the new spur and ring hammer, come with the hooks nicely prepped so I usually don't touch those.

 

[SACOLT]

Dave lookng forward to them.

 

[Magnumite]

I use a method using an old Wilson hammer jig and feeler gages to recut hammer hooks if needed - and I really don't like to do more than smooth the hooks if at all possible. I first cut the floor (if needed, just enough to get them square) by setting the hammer higher on the surface of the tool. I measure the floor to pin distance to make sure I haven't gone astray.

Using the Kuhnhausen book, I gather info to see how far off the outside diameter of the hammer pin hole the plane of the hook engagement surface is cut at. I put the hammer on the hammer bar which comes with the tool. The hammer is oriented on the hammer jig surface in the cut out with the hammer bar on top of it, hook engagement surface up. Then I place the respective size feeler gage under the hammer bar on each side of the hammer. Then I carefully use a safe side smooth cut file to touch the hammer hooks. I finish off with appropriate stones and even use the jig to break the top edge of the hooks.

By varying the thickness of the gages under the hammer I can get different angles on the hooks, though I normally use a neutral to undersquare hook angle.

Not sure of the responses I'll get on this, but using hand tools and jigs, I get safe, smooth results.

 

[Old Fuff]

Malikovski:

The hammer moves side to side quite a bit, and a 0.015" feeler gauge will fit between the hammer and the frame. Normal, or more than should be?

I don't know that this would be unusual with today's makers who buy their parts and pieces from outside sources, but according to my USGI blueprints The slot in the frame should be .310" - .315" wide, and the hammer should be .306" - .309" thick. So under the worst of circumstance you could get a .009" gap, but the chances of matching a frame with the widest slot with a thinest hammer are unlikely. 0.015" would seem to be a bit out of spec.

But I have no reason to think that the makers are paying any attention to Uncle Sam's drawings.

 

[Malikovski]

Slot is 0.319" and the hammer is 0.305", so a little large, and a little small respectively. As long as the hammer is moving straight back, I suppose there is no reason it would be pushed to one side or the other, but I don't like the amount of side to side twist that is possible. Perhaps new parts will remedy this to a degree as well

Thanks for pointing me to that other thread on hammer/sear interface. I read through some of the clinic threads, but I didn't see that one at the bottom, unfortunatlely.

Great read, but it did not quite cure me of inquisitiveness re: the 1911, and I get the feeling I ought to also get my hands on Kuhnhausen soon.