Lock Time

[Terry]

Does anyone know how the Lock Time of various actions compare?

 

[serial # 001]

This is from my notes from 1997. Maybe you can use it. Don't remember where I got it.

Brand Lock time Bolt lug area
miliseconds square inches

Remington 700 3.0 .107

Rugger 77 3.4 .104

Savage 110 2.7 .119

Weatherby Mark V 3.6 .104

Winchester 70 3.0 .073

 

[jonbearman]

I'll be darned,the savage beats them all hands down. I am amazed.

 

[Terry]

Anything on Custom Actions?

 

[BigDMT]

I always upgrade the firing pin and spring when building a rifle on any factory action. It's always a cheap and easy upgrade and can't hurt anything to hit the primer faster IMO. Wolffe or Tubb springs are always a sure bet for faster lock time.

 

[Robert]

I always upgrade the firing pin and spring when building a rifle on any factory action. It's always a cheap and easy upgrade and can't hurt anything to hit the primer faster IMO. Wolffe or Tubb springs are always a sure bet for faster lock time.

I am always very cautious about increasing spring force.
None of the replacement publish their characteristics, and I know from experience some of them are uselessly compressed over their maximal chatacteristics length. Publishing a force in pounds, Newtons, or whatecver means very little without the load at the cocked/decocked lengnght while in the bolt.

A soring maximal force is obtained at a certain length, usually about 2/3 of its initial lenght, which should be close to the decocked length in our case. Over-compressed would mean nothing else than excessive fatigue, as no extra force is obtained when over-compressed.

Now, if the replacement spring is only compressed to a fraction of its macimal force, it carries useless weight and, even if it is agreed that the sprig extra weight is only taken at half its value or the weoght in motion, this extra weight slow the locktime somewhat, as any extra weight additiont.

Elements who are to be considered for locktime:
-Spring load at the cocked position, which is not necessarily the maximal listed spring force.
-Mass of the parts in motion
-Lenght of travel. I would tend to consider here the travel at impact, when the striker hits the primer bottom, which is close to the total travel less protrusion.

For instance:
-Remington 700: FP travel dry firing = 270’’; at impact = .200.
-A match action I know quite well: dry firing = .157’’, at impact = .102’’.

Playing with one element only adds very little in terms off locktime IMHO. For instance on the above comparison, the length of travel at impact has been reduced some 100%, FP mass reduced by about 30%, Spring force some 45% and locktime more than halved.

Of course, mass and lenght of travel are design featires, not easily modifiable...It is howeber where more gain can be achieved.

But locktime reduction is not of te same importance for bench shooting or sporters.
R.G.C