Beretta 686 Silver Pigeon trigger assembly

What you describe sounds like a small lock-screw to keep the larger screw from working loose.
(if the small screw is in the edge of the large screw head)

However, that's just a guess.

Go here for a schematic and see if you can I.D. what you are looking at.

http://www.brownells.com/.aspx/pid=0/sid=894/schematicsdetail/686-Silver-Pigeon-Competition

rc

It's just as RC said, removing 78 will allow removal of 55. The only thing you'll need is a screwdriver that properly fits the screw slots so you don't bugger them up. Chances are good that 78 will be somewhat tight, and 55 may not be tight at all. Both should be RH thread.
When you put it back together, be careful of the alignment of 55/78. 78 should seat within 55 easily, without resistance.

Which means hollow-ground gunsmith-type screwdrivers, not your typical Ace hardware ones. Removing the stock should give you ample room to spray a cleaner on there to blow any gunk out, then relube. Taking apart any trigger group can mean springs flying if you are not familiar with it. I know with SxS guns it is best to have the hammers cocked when removing the trigger groups; I am not sure if it applied to Beretta actions as well

I would suggest unless you take your own clocks & watches apart to clean them, you do as oneounceload suggested.

Just take the stock off and hose it out with spray cleaner, and then re-lube it.

If you have a double gun like that with an inertia trigger that works though?
Don't mess with it!

O/U's don't get all that dirty inside the action.

rc

http://bbs.shootingsportsman.com/showthread.php?765-beretta-686-trigger

The advice is to remove the stock, flush out the guts and relube, and reinstall the stock.

I don't think you'll find anything at Midway that will be thin enough. This is what you want:http://www.brownells.com/.aspx/pid=44342/Product/MAGNA-TIP-reg-THIN-BIT-SET
That or grind your own.

There is a discussion here of how to do some of this on the 68x series. Including which of the thin bits you need to pull the trigger group. To clean the triggers you don't need to pull those two screws - but if you need to drop the trigger group out of the receiver you will have to remove those two screws. - and the one hidden under the safety.

http://www.shotgunworld.com/bbs/viewtopic.php?f=57&t=278811