Sear Jigs

[muscle]

Hi guys,

Im hoping to fit a new sear, hammer disconnector and trigger on my HS before sending it off to Ken Crawley. I figure since the gun is headed off to him anyways I can take advantage of learning a piece of the 1911 (I want to do a custom build eventually) and have it looked at by a good smith.

I read all night about fitting the sear to the hammer till my eyes started popping out of my head. Seems to me that all the differant sear/hammer jigs are not at all perfect.

And I dont expect to buy a tool in order to accomplish a task in an hour that takes 20 years to master... just a tool that can help me get started.

My question is, is there a jig that most recommend to get the parts close with some minor fitting? I realize that alot of higher end parts come from the factory in pretty good shape.

I've looked at the Yavapai and Marvel jigs. Seems to me that having the parts outside the gun in a jig is pointless as to what their relation is when inside the gun.

Ive also read somewhere that brownells sells a pin set that allows you to place these parts together outside the gun but I am unable to find anything on their site.

[Hawkmoon]

You are correct -- a jig is only as good as is its match to the hole spacing of the frame. If the jig is perfectly to spec, it works best only if the frame is 100% to spec.

The external pins fit directly to the frame, so they take into account any variations in tolerances. The Brownells part number for the 1911 is 080-622-001

[Anopsis]

I use those same pins to check my work. I use the Power Custom Series I fixture (also available from Brownells - sku# 713-070-002). It offers the ability to do sear and hammer work on guns other than 1911s (heresy, I know). I picked it up after reading Weigand's 1911 2.5# trigger job writeup on Brownell's website, and I'm very pleased with it.
I can't offer a fair comparison vs. other jigs, as I stoned stuff by hand before. Good luck!

[Spindly61]

I use both of the above also. You then need stones 1/2x1/2x6.
It gets a little pricey,but I am glad I got them. Keep us posted.

[gbw]

I use the Power Custom also, with good results. It's expensive, and will not do the hammer hooks (except height). The lowest pull I can get consistently is 3.5#. Any lower and I'm flirting with a trigger bounce - hammer drop, with which I'm not comfortable. 3.5 is fine with me.

The only way I've found to make sure the hammer and sear are in full contact in the pistol is to Sharpie the sear faces and reassemble, and test. Then, even if the pin holes are not perfectly parallel and straight you can correct for some minor offsets. The exterior checks haven't been totally reliable for me. Maybe others have found other reliable methods.

[Spindly61]

I don't have one yet,but it is on my wish list. Whats another $100.00.
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=928&title=YAVAPAI+1911+AUTO+SEAR+TOOL

[muscle]

Thanks for the info so far guys.

Is there a tool or method for squaring up hammer hooks? And I've read to use a squaring file/not use a squaring file....use a stone/not use a stone.

To me, using a file on the hooks would be drastic. Using a stone would take less material off but if the stone dulls, you have radiused corners.

[muscle]

And before somebody says it, I know probably the best way to square up the hooks would be on a mill. But Im wanting to be able to do this by hand on my benchtop. :D

[muscle]

I don't have one yet,but it is on my wish list. Whats another $100.00.
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=928&title=YAVAPAI+1911+AUTO+SEAR+TOOL

Yea thats the Yavapai jig I've been looking at. Allows you to use a micrscope to look at the fitment of the hammer/sear. The only thing I dont believe it does is allow you to look at both sides. But it is an interesting jig.

[gbw]

It is baffling to get conflicting advice. I once asked about widening a barrel hood with silver soldered shims. Got 4 different answers, all different. (I did it, it seems to work fine). Mr. 1911Tuner gives the best justification for his answers, by far.

FWIW: I use the HS file, very carefully, very slowly, to square up the hooks. Normally I see contact on only one side of the sear initially. It takes practice to get a feel for this. Then I stone them lightly when I see the contact I'm after. Also, probably everyone knows this, but when ready for final long-term assembly, I permatex or super-glue or lock-tite the left end of the pins. So the parts rotate about the pins, and not the pins in the frame.

[wichaka]

I use Brown's sear jig, and an old Tom Wilson hammer jig. The Wilson hammer jig isn't made anymore, but might be able find one ebay or the like. That's where I found mine.

Also get yourself some stones, an .020" shim, and a hammer hook squaring file.
Brownells sells the 1911 trigger kit that has the stones & file. Then pick up the adjustment pins, and shim.
Add a couple good manuals.......have much patience, and you should be good to go.

Just make sure to do all the safety checks before firing the gun.

[Kruzr]

I use the Power Custom Series I also. I use the external pins and a 10x loupe to check the engagement.

[Greg Derr]

The (Bob) Marvel jig is very good. It uses the external pins to check the sear/hammer fit. Allows you to square the hammer hooks and trim them. I also have the Power jig. I have a few others, but turn to the Marvel most often. I check the sear/hammer hooks in a machinists microscope. One thing I have learned with the stones is " less is more better" take only a few light strokes with each stone.

[wichaka]

One thing I have learned with the stones is " less is more better" take only a few light strokes with each stone.


Amen brother......... :)

[muscle]

I use the Power Custom Series I also. I use the external pins and a 10x loupe to check the engagement.


Thats a new one... 10x loupe?

Ive got an order building at brownells. The marvel jig and hook squaring file are both out of stock. The stones are on it including a trigger track stone.

[Spindly61]

Right now I use a 10x loupe also for engagement check also. I would like a little more though. It is the eyepiece type not the eyeglasses clip on.

[muscle]

Right now I use a 10x loupe also for engagement check also. I would like a little more though. It is the eyepiece type not the eyeglasses clip on.

so would something like this (http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=5769&title=OptiVISOR) work well or look for an actual 10x eyepiece loupe?

[pa_guns]

Hi

The only way I have found to really get the surfaces right is with the Sharpie. I have a number of magnifying gizmos, but none of them really beat a simple low power microscope.

I like the ceramic stones and keep a couple just for triggers. No matter what kind of stone they can get worn down faster than you might think.

Bob

[Spindly61]

I found this (http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=21162&title=POCKET+MICROSCOPE) for less. I'm going to order one too. Thanks for making me look.

[Jerry Keefer]

[QUOTE=muscle]And before somebody says it, I know probably the best way to square up the hooks would be on a mill. But Im wanting to be able to do this by hand on my benchtop.

Muscle;

The mill is very good, but the surface grinder with the properly dressed wheel is near perfection... The control is better and the surface finish is superior to the mill. I never do hammer hooks by free hand. It's nearly impossible to get absolute true and square surfaces. Good hammers are very expensive, and costly to ruin. I've been playing with the design of a fixture that would allow "out of the shop" (matches/Camp Perry, etc.) hammer work that is precise. There is a need, as none exist. A diamond lap supported in linear bearings perhaps. Still working on it. Also, as Gregg mentioned, a good tool makers microscope and an optical comparator are tremendous tools which allow infinate inspection, and micro adjustments to be made.
Good Luck

Jerry

[muscle]

I agree Jerry but a decent benchtop grinder or even a small mill would be way beyond the scope of the home gunsmither. The enjoyment gained by performing these tasks yourself outweighs the need to ship the gun out to get a precision trigger job done by someone reputable and having such equipment.

Im hoping to get an excellant carry trigger bordering on a match job done with some simple tools and perhaps a good jig.

So far im leaning towards the Marvel jig. :D

Keep us posted on your prototype jig...

[Jerry Keefer]

So far im leaning towards the Marvel jig. :D
.........................................................
I think you'll be very pleased with the Marvel..

Jerry

[pa_guns]

Hi

There certainly is room to improve the existing sear jigs. The jigs I have seen work, they just take a bit more user intervention than a lot of stuff. The amount of work isn't the issue, it's the judgement required.

With all the tool makers out there I hope we see something a bit better at a reasonable price.

Bob

[muscle]

Hi

There certainly is room to improve the existing sear jigs. The jigs I have seen work, they just take a bit more user intervention than a lot of stuff. The amount of work isn't the issue, it's the judgement required.

With all the tool makers out there I hope we see something a bit better at a reasonable price.

Bob


This is what Ive seen so far. Im thinking with a combination of a good jig, a pinset to allow you to see the engagement on the outside of the gun and a sharpie to see whats happening inside, I can put a reasonable trigger together.

On a side note, I am unable to find a marvel jig anywhere for sale... :(

[pa_guns]

Hi

Your success with the external pins can be highly variable.

1) The holes in the frame need to be square
2) The external pinset has to fit well in the frame holes
3) Your "normal" pins have to be a tight fit and be straight
4) The diameter of your normal pins and the external ones needs to be the same

If any of that's not true the external pins may not be telling the truth.

Bob

[1911Tuner]

Whew! Glad I don't mess with these ticklish trigger jobs. 5 to 5.5 pounds clean is more my style. :D

[pa_guns]

Whew! Glad I don't mess with these ticklish trigger jobs. . :D

Hi

But that way you miss out on the fun and challenge of a pistol that randomly fires 0 to 8 rounds with each trigger pull. :D

Bob

[berkbw]

Hi

Your success with the external pins can be highly variable.

1) The holes in the frame need to be square
2) The external pinset has to fit well in the frame holes
3) Your "normal" pins have to be a tight fit and be straight
4) The diameter of your normal pins and the external ones needs to be the same

If any of that's not true the external pins may not be telling the truth.

Bob

What would be the acceptable difference in end pin spacing on one side vs. putting the test pins in the other side? Would 1 - 2 thousands be OK?

b-

[pa_guns]

Hi

As Tuner points out it all depends on just how freaky you are trying to get.

One problem is getting the angles going in the wrong direction. If you do that then the hammer goes forward as you start to pull the trigger. The change in angle that makes or does not make that happen is a less than a degree as I recall. The desired condition is that the hammer stays steady or comes back a little as the trigger is pulled.

That's a lousy explanation - there's a lot better one in the sticky, but you should at least get the idea.

When you get close I know of no way to do it outside the pistol and get it right. I'm sure there are people somewhere who can, but I'm not one of them.

Bob

[muscle]

pa_guns wrote:

3) Your "normal" pins have to be a tight fit and be straight

The hammer and sear pin will fall out of the frame by excessive shaking. I thought that the hammer pins will usually fall out by their own weight. However there is no excessive play that I can feel by hand. Do i need to get oversize pins or is this acceptable?

I understand the holes in the frame needing to be square and by using the external pins I am simply getting the angles very close. Once this is done I would sharpie the sear and put the parts into the gun for final tuning. Im thinking this final fitting would show any deviation from being fitted outside the gun and be corrected then.

Would this be an acceptable method?

Tuner:

I dont think I will go below 4 1/2 lbs on this 1911. I agree for liability and safety purposes, there should be adequate pre-travel and trigger pull on a carry gun. Once the trigger can break clean without any creep, I can then proceed to adjust trigger pull by adjusting the sear spring and by using a heavier mainspring?

Also FYI

There seems to be differant Marvel jigs on the market. The first one is from Marvel Precision seen here. (http://www.marvelprecision.com/2002pics/searjig.jpg) The second one is a brownells variant seen here (http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=920&title=BOB+MARVEL+1911+AUTO+SEAR+%26+HAMMER+JIG)

Im thinking the brownells unit looks to be a better jig.

[Spindly61]

Unless you have a vast ammount invested in measuring equipment it is going to be very difficult to measure accurately.
All final fitting on a good trigger job is hand lapped or stoned with the parts in the gun. It takes a feel and experience to get there. If you are at a gun show and can pick up used sears and hammers I would. A good question is " do you know the minimum overall length a sear can be?" Drawings with tolerances are a must. Kuhnhausen manuals have some drawings but are not enough to make a pistol. Just right now I was looking for a tolerance for squareness for the sear pin hole and can't find one.
Some dimensions for the frame have refrences that are not even on the pistol. Makes it a little hard to measure. I am all for people doing a trigger job. I'm all for people grinding a cam shaft too. But how many would attempt it? I just want you guys to understand what you are getting into. Be prepared is my main message here. If you have all the equipment needed and information to know when something is in tolerance and when it is out of tolerance. I just want you guys to be safe. I guess these things are ticklish Tuner.

[pa_guns]

Hi

You can make a very nice trigger without going nuts about it.

The only point I was trying to make earlier is that unless all the parts are tight the external pins will not tell you the whole story. Simply put - save some money.

Bob

[Spindly61]

I wasn't going nuts about it . I just feel we get a little complacement about these things. The written word can sometimes be misunderstood because we have no clue on inflection. I just want people to understand what they are messing with. If I offended anyone it was not meant in that manner. I meant my comments in a constructive way.

[muscle]

Your point is well taken Spindly and speaking for myself, I do not take anything for granted. However I do feel with my skills, patience that I am up for it.

I agree that one thing one should have is a source for specs on these parts. I wiould be willing to take suggestions on that as well. ;)

[Spindly61]

Thanks muscle,
Jerry Kuhnhausen Manuals for tolerances.
"Colt 45 Automatic" "The US M1911/M1911A! Pistols"
I didn't mean to sound gruff or grumpy.

[Jerry Keefer]

[QUOTE=muscle]There seems to be differant Marvel jigs on the market. The first one is from Marvel Precision seen The second one is a brownells variant seen
Im thinking the brownells unit looks to be a better jig

Muscle;

Both were designed by Bob. The one you refer to as the Brownell model is more complex and is intended to also cut hammer hooks. It is more difficult to use and adjust. It lacks the fine adjustment screws and the rollers. I added the these features to mine. The fine adjustment screws allow precise metal removal, and make over cutting the sear face less likely.
The other (blue) is an excellent sear jig with the fine adjust/roller features and is more user friendly. Both are excellent.

Jerry

[muscle]

Wow thanks for the info Jerry. :D

As for the hammer hooks, isnt it just as important to cut these evenly as part of the overall trigger job? Ive read that .20 is fairly standard for a match trigger, however for a carry gun maybe broaden that to .24 to .26? (with the sear primary angle at .20 with proper break angle) Without some sort of jig to cut the hooks evenly how would this be done?

[Jerry Keefer]

[QUOTE=muscle]Wow thanks for the info Jerry. :D

As for the hammer hooks, isnt it just as important to cut these evenly as part of the overall trigger job? Ive read that .20 is fairly standard for a match trigger, however for a carry gun maybe broaden that to .24 to .26? (with the sear primary angle at .20 with proper break angle) Without some sort of jig to cut the hooks evenly how would this be done?

Yes: Very important.
Those numbers are about right. Yesterday I mentioned that the precise dimensions of the hammer are very difficult to achieve by hand. I do it with machinery and instruments that are capable .0001; but many smiths can get satisfactory results with feeler gages; stones; etc. and I don't mean to imply that your undertaking is futile.. Not at all. With care, I am sure you'll do fine, and most shooters will be pleased with the finished trigger job.
Take Care & Good Luck
Jerry

[wichaka]

Yes, it is important for the hooks to be even and square.

020" is the norm for aftermarket hooks anymore. I like mine around .023", but have done many with the .020" measurement.

I think the adjustment pins are important, as you can't see the engagement with the parts inside the gun. And they'll let you know right off, how you're doing and if your pin holes are off a bit.........given the hammer and sear is in proper spec.

[1911Tuner]

Veering off-topic just a bit...Anybody familiar with the past practice of the
"Cheater" trigger job that some of the old slow-fire Bullseye shooters got caught using once upon a time? IIRC, NM limit was 3.5 pounds. (Never shot pistol in BE competition.) The "Cheater" let them check to specs, then gave'em about one pound with a little sleight-of-hand. Very ticklish...and risky if not done correctly, both in the mechanical execution and in practice.

[pa_guns]

Hi

You can make a very nice trigger without going nuts about it.

Bob


I wasn't going nuts about it .


Hi

It's amazing what can happen when you *assume* you know which message is right ahead of the one you are typing. I obviously need to use the quote button more often. When I started typing the message qoted, I was looking at one that was a couple back.

and

No, what was the magic Bullseye trick, break the sear spring after the test? :D
(so much for using the quote button - obviously need more practice).

Bob

[Spindly61]

How was it done? Just a wild guess, 2 sets of hammer hooks?

[1911Tuner]

Nope and nope. No disassembly required. Very neat little trick, and very hard to catch. Betcha Keefer knows about it. ;)

If I tell ya the secret...promise not to use it? :p

[gbw]

I'd love to hear it, and DO promise not to use it.

[1911Tuner]

I'd love to hear it, and DO promise not to use it.

Suuuure! And the check's in the mail...right? :D

A'ight. A quick description and I'll stop hijackin' the thread.

For informational purposes ONLY! Y'hear? ;)


Okay...On your collective honor not to try this at home.

Once the thumb safety is correctly adjusted to block all sear movement, the smif scrapes a little material away from the fitting area of the lug, so that the sear will move when the trigger is pulled...but not enough to let the sear get out of the hooks. With careful "fitting" the sear can be moved as much as 3/4ths of the total hook length, creating a "Redneck Set Trigger."
Most don't push it that far though, and settle for half the total.

When it's time for the shot, the shooter flips on the safety...feigns a practice squeeze or an intense focus before takin' the shot...or anything to conceal what he's doing. Time for the shot...safety comes off, and ...Ba-Da-Bing! Instant 16-24 ounce trigger. I've seen some let off at 12 ounces. Very ticklish triggers. Very risky bidness.

Best results are obtained with squared hooks. Undersquare hooks tend to pull the sear back in. Oversquare hooks tend to push the sear the rest of the way out and fire the gun before you're ready.

Told ya it was risky...

[muscle]

Tuner that setup could also create a runaway gun it seems with the safety off.

[1911Tuner]

Tuner that setup could also create a runaway gun it seems with the safety off.

Don't see how. When the safety is off...it's off. How it functions...or malfunctions...when it's on doesn't affect how it functions when it's off.

[pa_guns]

Hi

Let's see - time for a new fixture ... :D

I suspect the magic safety "fix" depends on a fairly stable trigger job at 1/4 engagement left. As things wear it could get a bit exciting. Of course you could just use the safety as a trigger ...

Bob

[muscle]

yea i had to grab my 1911 and look at it to see what you mean. the safety would allow for sort of a set trigger. Yea the trigger would need to definately be stable for something like that. would be pretty scary..

[1911Tuner]

Of course you could just use the safety as a trigger ...


'Fraid not. If the sear gets out from under the hooks, the hammer will knock the safety off just as surely as if you thumbed it down.

Like I said...We are trained perfeshunuls. Don't try this at home.