Recoil spring question

[Hockey7711]

I have a S&W model 39, and noticed that there are different recoil springs available.
The original with unknown rating, a 16lb, 20lb, and 22lb.
If I switched to a lighter or heavier one, what would the effect be?
I've been having some ejection problems lately, might this help?

 

[Jim Watson]

Wolff thinks the standard is 14 lbs. I would not go up or down more than one notch for standard ammo.
But what kind of "ejection problems?"
My first response is to clean out from under the extractor.

 

[cfullgraf]

If the recoil spring is too heavy (strong, stiff, high spring rate, choose your definition), the ammunition used may not cycle the slide to eject the spent case and pick up the next cartridge.

If the spring is too light (weaker, low spring rate), the recoil from the ammunition will beat the gun harder under recoil that may cause damage to the gun.

If a 14 pound spring is standard, with standard ammunition, a 16 pound would probably work fine but you may get a few cycle problems with the occasional light cartridge.

 

[Hockey7711]

When it does eject, it doesn't throw the cartridge very far, sometimes not at all, causing a jam.

 

[12Bravo20]

OP,

Does your pistol have the aluminum or steel frame? If it is the aluminum frame then you definitely do not want to go too light on the recoil spring weight. While I do not know much about S&W pistols, I do know that other brand pistols with aluminum frames will get beat up bad with a worn out or too light of a recoil spring. I would also stick with the OEM weight for the recoil spring if you shoot mostly bulk 115 grain ammo.

I would go ahead and remove the extractor and make sure it and the slot it sits in is clean. If the extractor is sticking, it can cause ejection problems as much as a bad recoil spring can.

 

[Robbins290]

Normally what I do is start with the heaviest and work down until it cycles. All of my 3rd gens are on the heavy side with recoil springs and they run like a top.

 

[RainDodger]

I had a Model 39 for many years. Generally they work quite well and I would use a stock spring and figure out where the ejection problem is, before adding an unknown. As said above, I would thoroughly clean under the extractor and ejector, and make sure the breech face is spotless... basically make sure the pistol is super-clean, with a new, factory recoil spring. In that state, it should work great with factory ammo. Then report back how it's working... my two cents.