A strong lower temp silver solder??

[PKLeRay]

Fellas I am on the final stretch of a build and, I had to cut off and move some lugs that were cast in an investment cast brass trigger guard. The areas are thin so i dont want to use a silver "braze" since the melting points are so close. Whatya guys use?

[Acer Saccharum]

You could cut a rectangular hole in the finial, and fit the tenon into the hole, then peen the tenon over.

[kutter]

I'd make a new lug from sheet brass.  Same idea as some make bbl lugs from sheet steel.
Fold the sheet brass over on itself then spread the feet out at a 90* angle. The feet set on the inside of the guard,so you can file them a little for a nice contact.
Sometimes those who make bbl lugs like this sweat solder the standing section together with hard solder ('silver solder').
 I'd run some soft solder into the joint just to make the assembly as one.  I wouldn't bother with high temp silver solder.

Then simply soft solder the new lug in place on the guard.
The extra surface contact of those 'feet' makes for a very strong solder joint. You can make them as large as you want on the inside as far as the contact surfaces go and it'll beef up an extra thin guard .
A little extra depth to the inlet is needed but only enough to accomodate the thickness of the sheet brass 'feet' .

[sydney]

Hi Check brownells they have several different temp solder
   also jewelry supply houses
      Sydney

[Blacksmoke]

Rio Grand Jewelry supply house have a brass colored solder that I have used many times on cast brass. It flows at a lower temp than brass and is just as strong as silver braze.  Great for soldering on lugs to trigger guards.     Hugh Toenjes

[LRB]

  Use Brownell's Silvaloy 355 silver braze. Very strong, easy to work with, flows at 1205°. Excellent for brazing brass.

[smart dog]

Hi PK,
I've done exactly what you describe several times.  I do what Acer described but use round stock and a round hole, countersink the hole and peen the post.  Then I use Brownell's Hi-Force 44 low temp solder which contains 4% silver and flows at about 475 degrees.

dave

[T*O*F]

Then I use Brownell's Hi-Force 44 low temp solder which contains 4% silver and flows at about 475 degrees.

Ditto.  Why risk overheating your guard and having it sag or melt?  If you wanted to do that, you wouldn't even need solder.  You could just flow the two pieces of brass together.

[LRB]

  The heat used in Silvaloy 355 will not cause sag, and is very much stronger than Force 44. Just propane used with a Mapp gas torch head will do the job quickly. In this case, even a standard torch head may work.

[E.vonAschwege]

You've already received some excellent answers, but I'll add my 2c.  Silver brazing will make a joint almost stronger than the brass itself.  I use "Easy" solder, which flows around 1150 degrees - well below the melting temperature of brass.  I also use a brass color solder that melts around 1250, makes for nearly invisible repairs on brass and tarnishes dark.  I use propane (two if needed) and have never had anything sag or melt.  If you want to use soft solder, you can stake a lug much like doing so for a barrel staple, then heat and solder for extra security. 
-Eric

[Scota4570]

I recently used, Bernzomatic pc3,  melting temp 1310 deg F melting temp.  You can use mapp gas.  Them temp is considerably lower than other brazing rods. 

The color is just a little darker than the brass of the trigger guard I used it on.  I could build up material with it and add on. 

[Hungry Horse]

 I'd use Stay-Brite silver bearing solder. It melts at about 400 degrees, and is so strong that a trade gun I helped a friend build survived a load with an air gap. The barrel pins looked like miniature handlebars, and the lock bolts were bent. But the soldered on lugs remained in tact.

           Hungry Horse

[jerrywh]

 What Blacksmoke is talking about is called silvalloy 45. That is what I use for theses type of jobs. It maelts and flows at about 1245°F.    I use this flux.
http://www.riogrande.com/Product/Handy-Flux-Paste-for-Soldering-and-Annealing/504083?Pos=1
If you are not sure of yourself just practice on some scrap first.  you can find silvalloy 45 on the web.