Proper Mainspring Tension per Douglas Wesson

redwagon32 · #1 05-17-2020, 12:14 AM

I was reading my 1938 copy of Douglas Wesson's "Burning Powder" recently and saw that backing out the mainspring tension screw "several turns" resulted in a dramatic loss of accuracy even if there were never any misfires.
I assume there has been a big increase in primer quality in the last 80 years and I also know many people now use Wolff springs to improve the trigger pull and keep closer to the same hammer force. Has anyone experienced this much loss of accuracy by reducing mainspring tension?

ArchAngelCD · #2 05-17-2020, 12:55 AM

Sorry, I never noticed a loss of accuracy with a backed out screw. Interesting though.

Protocall_Design · #3 05-17-2020, 10:38 AM

This phenomenon is pretty well documented. Few shooters will ever encounter it though, because you have to be shooting at a bench rest rifle level of accuracy to see it. He doesn't say what distance the shooting was done at, but probably at least 25 yards, maybe 50.

Most people can't shoot one hole cloverleafs as pictured to begin with, so it's unlikely they would ever find this situation. Many revolvers are capable of this level of accuracy with the right load in a Ransom rest, however.