I own a model 1911 "Pro Series" that I purchased about a year ago. After putting about 1,200+ rounds thru it, I think it's time for a new recoil spring, but because it's a 9mm no one seems to know what tension spring came with the gun from the factory. I've even called S&W and for some odd reason they wouldn't tell me. I'm thinking it's about a 10lb. to 12 lb. tension spring. If one of you folks knows exactly what the factory tension is I'd appreciate knowing. Thanks for reading my question.
Barrie99

1,200rds is hardly enough to worry about a recoil spring. If you are using standard 9mm ammo you should be plenty good for 5k+ before replacing. The main thing I look for is how far is the ejected brass flying, 4-6' is what I like to see, if it's more then I go with a new spring. 12# is probably right but I go back to the ejection pattern, if further go heavier, falling out on your hand you need a lighter spring.

Sir:
Thank you very much for a clear and very well explained reply to my question. Happy plinkin'

Colt lists an 181/2 pound spring as standard for the 1911 9mm/38 super.

I have tried that spring but dropped to a standard 16 pound spring as I shoot moderate reloads.

A 12 pound spring will work, but would be really light for full power loads.

BLM

Bruce Lee:
Thanks for the additional information, I will get a 16 lb. spring and try it as I only shoot 115Gr. round nose ammo, nothing hotter than that. Thanks again.
barrie99

I also have the S&W 9MM Pro Series and I'm pretty sure the factory spring is 16lb, possibly 18lb. Flings the empty's about 7 feet.

__________________
Virtue,Liberty & Independence

7 feet is more than enough for me, thanks for the info, it is much appreciated.
barrie99

I purchased a S&W pro, I also purchased a "recoil spring gauge" when I purchase a new 1911, I take it down for a cleaning and lube, at that time I measure the recoil spring, my new S&W 1911 Pro 9mm recoil spring measured 11 lbs, keeping track of the rounds fired through it, I'm now up to 3,300 and I keep checking the recoil spring still at 11lbs, brass drops at my feet as the did when the gun was new. I shoot light loads with cast bullets. Purchasing a recoil spring tester takes the guess out of should the spring be replaced.

I didn't know they were available, I will look into it. You say the rounds drop at your feet, one guy said they he thinks they should eject 3 to 4 feet away. I'm not a gunsmith so I really don't know how far they should eject but given what you said, which is really what I wanted to know, 11 lbs. is right if that's what the gun came with from the factory. Thank you.
barrie99

One thing to keep in mind with the recoil spring testers is that they don't always match the rating that the factory gives. They're great when comparing one spring you have to another, but just checking new springs out of the package they often will run 1-2# different rating than marked. I have a couple of guns that I just use for Bullseye with very light loads, they are sprung to just drop the brass out at my feet. That's fine for that type of gun/shooting, but you wouldn't want that in a gun use for self defense or combat shooting because of the possibility of a jam.

Thanks to everyone who answered my question regarding the tension of the stock recoil spring on the 1911 9mm S&W "Pro Series". Just as an fyi to all, S&W told me that the gun came with a 20lb. spring, I find that a bit hard to believe as the brass only goes about 2 to 3 feet after being ejected. From all the replies I received I think I will stick with a 16lb. spring and see what happens. Again, thank you to all who replied.
barrie99

The 20# sounds like the hammer spring, 10mm is the only one I've heard of using that high of a recoil spring. I just took my 1911 Pro Series 9 spring out and checked it with my gauge and it measured 11#. Like I said earlier it usually runs a pound or two light of what the package gives for a rate. You can try the 16# but I'm guessing if it ejects it won't be far.