A quick search on old posts concerning trigger adjustments on the older Vanguards shows that all references to the original vanguard have been pulled. If you can get an older manual, or if one of the Nation members has an old manual, if an adjustment can be made, it'll be in there. My 2007 manual says "Unload the rifle, remove the trigger guard assembly, loosen the lock nut on the front adjusting screw. To increase weight of trigger pull, turn the front adjusting screw clockwise until the desired pull weight is established. To decrease the weight of the trigger pull, turn the front adjusting screw counter-clockwise till desired weight is established." Actually theres not much adjustment that will happen when adjusting it this way, but thats all you can do. You have to be careful not to back off the screw(while decreasing the pull weight)or the safety will lock up and not work.( you'll have your rifle in the safe position but you can still pull the trigger and it will go off which is extremely dangerous) Putting in the Timney trigger is the best advice I can give you, and you won' regret it.