RE: How important is Locktime?
Barrel Time and Lock Time - You may have heard these terms before. The reason they're important is that a gun and/or a marksman can move enough to throw the aim off target by the time the bullet actually leaves the barrel. The faster the barrel and lock time, the less affect movement will have on aiming point. It's worth considering when you're shopping for a gun, barrel length, and cartridge.
Two things affect barrel time: Barrel Length and Velocity. Sometimes rifle shooters are shocked at how accurate single shot pistols can be. One of the reasons is that the single shot pistol's shorter barrel cuts the barrel time tremendously. Consider a 10¾" BF Silhouette Pistol in 7mm US. A 140 gr bullet traveling 1900 fps takes just .47 milliseconds to travel the length of the barrel. Now consider a 26" rifle in 7mm Remington Magnum. A 140 gr bullet traveling 3100 fps takes .70 milliseconds to travel the length of the barrel! The 7 Mag has a slower barrel time than the 7US... Shocking, isn't it? Well, the lesson to be taken from this comparison is that an extra few hundred feet per second gained by a longer barrel may actually be a handicap when the increase in barrel time affects your ability to shoot accurately. What's more, a slightly slower cartridge in a well balanced barrel length might be more natural pointing while giving the same or comparable barrel time to a long barreled magnum.
Lock time is affected by the quality of your trigger system and the complexity and travel of your firing mechanism. A bad trigger makes it difficult for the shooter to anticipate sear release. Drag, creep, roughness, etc. The shooters trigger control affects his timing. Beyond this, the complexity of the trigger affects the lock speed. For example, to achieve light trigger pulls, some trigger systems have compound linkages that might slow the sear release. A T/C Contender actually has two sear releases. The first is directly released by the trigger. That sear swings up and actuates a sear connected to the hammer. This lets the hammer swing forward. A dramatic example of slow lock time is the old Flintlock firing mechanism. The trigger releases the hammer which strikes the frizzen and a spark falls into the flash pan. The flash powder ignites in a Phoosh and the flame travels from the pan into the barrel to ignite the main powder charge. Try and keep holding the sights on target while all of that is happening! Thankfully, modern firearms locktimes are much faster.
On hammer based actions, look for simplicity in trigger mechanisms and short hammer travel distances to get the fastest lock time. On in-line actions such as bolt actions, look again for fast trigger systems and short traveling firing pins. The long firing pins in bolt guns have a lot of mass to accelerate but in recent years, the introduction of lightweight titanium firing pins (available as an aftermarket kit) has helped.
So What's the Point? Everyone has been taught not to jerk the trigger, not to flinch, and not to breath when aiming and firing a shot. Probably airgun shooters and shotgunners are more keenly aware of "following through"... keeping the aim on target all the way through and beyond the trigger squeeze. All of these are the things you do to minimize the effects of barrel time and lock time. You should also take barrel time and lock time into account when deciding which gun to buy, which cartridge is suitable, and and how long of a barrel would be best.