This might sound like a joke to some of you, but maybe there's a "gunsmith way" of doing this..

The white dot on the front sight of my USP "fell" out at the range yesterday, I just got the gun and its the 2nd time out with it, WTF?? I didn't even think that dot CAN fall out, I thought it is painted on.

Where the dot was theres a little indention, I was thinking of dropping a very small drop of white-out or white paint in it.

Any suggestion?? I figure I'm not calling HK and be without my gun for 6-8 weeks...

The dots are just paint.

The reason they often fall out is, the installer doesn't take time to degrease the hole, and the paint doesn't adhere well.

To repair, use a solvent like lacquer thinner to degrease the hole, then dry it.

You can use model airplane paint, appliance touch-up paint, Wal-Mart hobby paint from the paint department, or even something like White-Out.

For the price and durability, model airplane paint is the best buy.  

Personally, to insure a long lasting job for the customer, I used Rust-oleum gloss white paint.
I bought a small can and transfered it into some of the small model paint jars.  
The gloss showed up better than the flat.

STIR THE PAINT, or you get too much solvent and it doesn't do as good a job.

Apply it with a toothpick or a small artist's paint brush.

LET DRY until BONE dry, then apply lube to prevent rust.  It takes the paint longer to dry down in the hole.

THANK you, for explaining the why and how to repair, I am greatful that we have people here that gives truly useful informations. Can't say that about some other forums...

off to model airplane store...

A few years back, Teddy Jacobsen advised me to use Testor's model enamel and put a coat of clear over it.

found some white gloss Rust-oleum for the lawn chair project this spring, easy enough to put a tiny drop with a toothpick.. Now the front dot looked just like the rear dots. I'm a happy camper again

Lets hope it stays put.  When you say "apply lube to prevent rust"  you mean things like BF CLP or Hoppes oil etc.. nothing fancy, right?  or do what hamishdhu suggest, a clear coat of enamel (eg nail polish, since I can "borrow" the wife's ??)

Any lube to keep the sight from rusting.  
You need to do this IF you degreased the sight.  If you didn't, the dot may come out again.
If you did, there's nothing on the sight now to keep it from rusting.

I never added any clear coat, since the Rust-oleum hardens up quite nicely.

Quoted: Any lube to keep the sight from rusting.   You need to do this IF you degreased the sight.  If you didn't, the dot may come out again. If you did, there's nothing on the sight now to keep it from rusting. I never added any clear coat, since the Rust-oleum hardens up quite nicely.

Thanks again, I think I understand your post now, I was thinking putting lube "on top" of the white dot once I painted in... but you are referring to the sight material become rusting. dah  

by the way, any recommendation on a sight pusher that will work for all of the following?
SA 1911s, GLOCK, HK USP, SIG 229, Beretta 92fs.. the slides all looked different, especially the Beretta with the safty right there by the rear sight!

got to be something "idiot" proof , solid build, and "affordable" (like under $200 ).. I am danger to my poor guns with a hammer and a drift punch!!

The gun owners best friend:  Brownell's Gunsmith Supply:
www.brownells.com/

Buy ANYTHING from them, and they'll send you a free catalog.  It's the best catalog in the gun world.

Some sight tools:
www.brownells.com/aspx/NS/store/productdetail.aspx?p=9777&s=25256

www.brownells.com/aspx/NS/store/productdetail.aspx?p=8846&s=21913

AND hold on to your wallet:
www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=6841&title=UNIVERSAL+SIGHT+INSTALLATION+TOOL