The idea that aftermarket triggers "just need to be installed and they work", isn't always so. Yesterday, I installed a new Timney on a Weatherby Vanguard. The Vanguard was a wood stocked model that wears a .300 Win Mag barrel. The new trigger was fastened to the action with no problem, and the pull weight and over travel were adjusted. Sear engagement was good from the factory. After placing the barreled action in the wood stock, the sear wouldn't catch the cocking piece as the bolt was closed. The stock had a tall 'pressure pad' in the forearm barrel channel, you could see the barrel move as the front action screw was backed out. OK, the action is being tweeked by the overly tall pressure point. Using my barrel channel tool and a scraper I removed most of the pressure pad. (Some light barrels benefit from slight upward pressure to dampen harmonics.) Same result, so completely floated the barrel. Re-installed the barreled action, same result. I put a dial indicator on the action before I loosened any guard screws. Here's another problem, the bedding isn't nearly "stress free". With the action under stress because of the bed it gets fastened to, it had the Timney still "jacked-up" to where it wouldn't hold the cocking piece (and firing pin it's attached to). I removed the barreled action again, and increased the sear engagement. Re installed the barreled action, same result. Increased the sear engagement more, still no success. The proper solution here is to do a stress free bedding job, preferably using pillars. My client didn't want to spend the money for a bedding job. He had me re-install the factory trigger. I spent over 2 hours on that Vanguard. I didn't earn a thin dime! So the moral is, what's touted as "drop-in'" isn't always. especially when dealing with wood or a flimsy 'plastic' stock. The Timney I installed on a X-Bolt, right after that, required about an hours stock work so the safety would function properly.