Savage Model 12 VARMINT

A friend of mine owns the above rifle and is having problems with the rifle firing. It has been allright shooting chucks since he got the rifle but now it refuses to fire every time. He is using factory loaded Winchesters. I forgot to ask him if the primers were dimpled.

It is in .223 caliber and the owner says there is a nice healthy "click" when the adjustable trigger is pulled, but no "boom". Then sometimes it fires when he pulls the trigger.

Bolt has been pulled and firing pin checked. Cleaned with brake fluid.

Took rifle out last Saturday to shoot some pasture poodles and rifle would not fire. It has got me beat! Told him to take it to his local gunsmith and have him look at it.

Could there be something in the Accu-Trigger mechanisms that could be causing this?