Recoil springs: give me the scoop on these again?
Higher than normal spring weight will do what for you?
Lower than normal spring weight will do what for you?
I seem to remember one of them reduces perceived recoil, but for the life of me, I can' recall... so I'll ask the resident experts for a quick refresher course.
You've touched on one of my favorite subjects... One that I've made a study of for years, with several conclusions drawn. The main one being that it's better to be slightly undersprung than oversprung... for reasons of functional reliability under all conditions, assuming that all else is well with the gun.
If you remember only two things about a recoil spring, (or any spring) remember that a spring works both ways. The other thing to remember is that whenever you change a spring rate or load, it affects the timing of the slide by increasing or decreasing the speed in one direction or the other
The elapsed time of the cycle isn't changed much if at all.
The time required to complete one full cycle will be about the same regardless of the spring rate. It will simply be biased in one direction or the other, depending on whether you go lighter or heavier. To sum up the action of a recoil spring as simply as I can:
Heavier equals slower backward and faster forward.
Lighter equals faster backward and slower forward.
Heavier reduces impact stresses between slide and frame. It also makes the gun more sensitive to "Limp Grip" syndrome.
Heavier Increases impact stresses between the lower barrel lug and the slidestop crosspin. Slower backward equals faster forward. No way around it. Going to a heavy spring doesn't really "protect" the gun. It just changes the place that takes the beating.
Heavier makes the magazine timing more critical. The faster the slide moves forward, the less time the magazine has to catch up... especially on the last round when mag spring tension is at its minimum.
Heavier doesn't increase or decrease recoil. Recoil is what it is, and is wholly determined by mass and velocity of the bullet and the weight of the gun. What it does do is tire your hand more quickly because you are fighting two separate forces. Muzzle flip, and the push of the stronger spring as the mass of the slide attempts to overcome the resistance of the spring. Simply put... as the spring is compressed, it's fighting to un-compress against your hand at the same time. The stronger it is, the harder you have to fight it. You won't notice a lot of difference between a 16 pound and an 18 pound spring until you fire about 8-10 magazines in a row in fast succession, but the difference is there.
For what it's worth, I've compiled a lot of data in the last 20 odd years on recoil springs. At every opportunity, I've hit local... and some not-so-local gun shops and tested the recoil springs in new pistols. Even though the accepted load/rate for a Colt Commander is 18 pounds, I've never found a new Colt Commander that was delivered with a spring that hit that mark. Most fall between 15 and 16 pounds, and some have been as low as 14.
I've encountered very few Colt Government Models that were equipped with the standard 16-pound spring. Most of those are dead on at 14 pounds. I've also noticed that fewer Colts give problems with stovepipe stoppages and rideover feeds with the magazines supplied... both of which are usually caused by overspringing.
Installing a heavy spring to force a balky pistol to go to battery more reliably is a band-aid that covers the real problem, and isn't a reliable way to accomplish that goal anyway. Much better to tweak the gun to go to battery with a 12-pound spring and use a 16 than to force it to battery with an 18 or 20 pound spring and hope for the best.
One last point in case you're concerned with reducing slide/frame battering is that there's another spring at work in that function. The mainspring. Mainspring loading determines how much resistance the hammer offers to the slide as the slide moves rearward and pushes the hammer to full cock. You can increase the mainspring loading and get the same buffering effect with alighter recoil spring as you can by going to a heavier recoil spring alone... and you can do it without the magazine timing issues that can pop up to spoil the show.
CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.
In May 2000, while shooting 460 Rowland level loads in a 20 ounce Patriot pistol, I was taking a severe beating. I started flinching by pushing my shoulder forward with each shot.
per Recoil Spring Selection Tips (by Bill Wilson)
The stock spring was just tuned for 7.7 gr. of powder.
I built a 42 pound triple recoil spring assembly tuned for 10.8 gr., and the flinch went away.
I was shooting quantities with 14.6 gr. when I got the flinch.
The heavy spring was not right for the heavy loads, but gave less slide to frame shock.
0) 45 acp................. 185 gr. 7.6 gr. AA#5 jams w/stock Patriot spring
1) 45 acp..................185 gr 10.2 gr AA#5 1100 fps 18,000psi
2) 45 acp +P...............185 gr 10.8 gr AA#5 1200 fps 21,700 psi
3) 45 Super................185 gr 12.4 gr AA#5 1312 fps 28,000 cup
4) 460 Rowland............ 185 gr 14.5 gr AA#5 1500 fps 38,800 cup