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View Full Version : Which sear jig to get?


yggorf
December 18, 2009, 07:23 PM
I've gone through the Brownells catalog and they offer 4 sear jigs:

1. http://www.brownells.com/.aspx/pid=1299/Product/1911_SEAR_JIG
2. http://www.brownells.com/.aspx/pid=21082/Product/ULTIMATE_1911_SEAR_JIG
3. http://www.brownells.com/.aspx/pid=920/Product/BOB_MARVEL_1911_AUTO_SEAR___HAMMER_JIG
4. http://www.brownells.com/.aspx/pid=17780/Product/SEMI_AUTO_SEAR_JIGS

Most of these are made by Marvel. Which is the one to get, or do I need more than one to be set up to do hammer/sear/trigger work?

stiles
December 18, 2009, 08:40 PM
get 4

yggorf
December 18, 2009, 08:48 PM
Stiles, do you mean get #4 on the list or get all 4?

dreamweaver
December 18, 2009, 08:51 PM
I have the first one on your list. works OK, but need to be careful not to get carried away. i had to buy a new sear and hammer for my commander after an over done trigger job made it go full auto!:eek:

stiles
December 18, 2009, 09:13 PM
yes get number 4.

yggorf
December 18, 2009, 11:11 PM
Hold the phone! I just found even more of the damn things:

5. http://www.brownells.com/.aspx/pid=928/Product/YAVAPAI_1911_AUTO_SEAR_TOOL
6. http://www.brownells.com/.aspx/pid=9853/Product/SERIES_I_STONING_FIXTURE
7. http://www.brownells.com/.aspx/pid=9875/Product/SERIES_II_STONING_FIXTURE
8. http://www.brownells.com/.aspx/pid=9875/Product/SERIES_II_STONING_FIXTURE

Why so many?

Tom-C
December 19, 2009, 09:49 AM
Yggorf

The differences in the fixtures is versatility. Anything made by Ed Brown, Al Marvel, Bob Marvel or Ron Powers is going to work well. The differences reflect how they made tools for themselves before things like this were commonly available

The more expensive fixtures are more versatile and more durable. The Ed Brown, Al Marvel and Bob Marvel products are 1911 sear only. The Ron Powers Series I is for sears and some work on hammers. For the 1911 it does great on both. For other hammers you need the Series II. The Powers Fixtures will work on almost any sear and hammer, but you need to buy adapters for each.

If you are going to work on hammers and sears get the Brownells Trigger, Hammer/Sear File and Stone set. Set it aside and ONLY use it on hammers and sears (http://www.brownells.com/.aspx/sid=3380/sku/Hammer_Sear_File___Stone_Kit). That way the corners stay sharp. Also a set of Trigger Adjustment pins (http://www.brownells.com/.aspx/pid=677/Product/TRIGGER_ADJUSTMENT_PINS)

You can also polish the faces on a 1911 hammer with a lathe tool (HSS steel) and lapping compound. The lathe bit is inexpensive, hard steel and lasts forever.

yggorf
December 19, 2009, 08:56 PM
Do the Marvel and Power jigs all do both hammer and sear stoning? Is it necessary to do both?

Tom-C
December 20, 2009, 08:45 AM
There are several parts to a trigger job on any 1911. The hammer and sear are important but only two of the parts. The trigger has to fit tight and still ride smooth in its track. The disconnector needs to be polished where it touches the trigger/sear and be smooth in its hole. A lot of the final effort necessary to pull the trigger is resistance to the sear (3-finger) spring.

There are two parts in smoothing the sear, the primary angle and the secondary or relief angle. The primary angle must be precise all the way across and all the various fixtures enable you to do that more precisely and repeatedly. All of the tools help you with the primary angle because that is the critical one that touches the sear. Realize that there will be only about 0.020” of contact between the hammer and sear.

The relief angle lets the sear get closer to the hammer so a smaller length of hammer hooks can still work. It is not as critical for either angle or length. The flat should be almost as wide as the primary angle and here is where the adjustment pins and a good magnifier really helps (especially with old eyes). Only some of the tools help with this because it is relatively easy to do with just a stone and the sear in your hand. Both the Marvel’s and the Ron Powers Series I both do. The Ed Brown and the Brownells do not.

The hammer needs the hooks shortened to about 0.020” This can be done in the Ron Powers Series I or in a bench vice. Both require that you put a feeler gage blade on the hammer and cut the hooks down to match. Then you need to polish the face of the hooks, while maintaining exactly 90° to the face of the hammer. You can do that in a Ron Powers Series II fixture or on a lathe tool with some lapping compound.

All these things can be done by hand without any fixtures, but how many sears do you have to ruin before you have paid for the fixture? The Ron Powers Series I will also do most other sears with other adapters.

Also if you do any work on any of these parts, when you take it to the range, load only one round and shoot it about 5 time or so to ensure you did everything correctly.

Have fun

yggorf
December 20, 2009, 12:22 PM
Thanks Tom-C. It sounds like the Power Series I or II (I assume the II will do everything the I did and more) is the one to get.

One more question on this subject - I notice some manufacturers offer sear, hammer, and disconnector sets that are supposed to be EDM cut, highly polished, and matched. If I just buy one of these sets, can I avoid the work the jigs are made for completely?

Tom-C
December 20, 2009, 05:02 PM
Both Powers fixtures will do both hammers and sears.

I have a Powers Series I fixture, lots of stones and quite a few adapters so I have never felt the need for a Series II or to buy the matched sets.

The firearms industry is very competitive. Brownells and Midway only sell what works. They both have extensive gunsmith sections and will take back anything that you are not happy with. There are a number of well known companies that make matched sets and if they didn’t do what they advertise, then Brownells and Midway would not carry them.

The “drop in” sets (sear, sear spring, hammer and disconnector) go for about $145 to $200 at Brownells. An EGW “matched and ground: ready for precision fitting” set with the same parts is $85.00.