What weight recoil spring for STI 2011?

[fieryotaku]

STI told me 12# but Dawsons website says 9-10 is what I need which one is correct?  I am only shooting 115 and 124 RN factory ammo out of it I also have my slide milled for an optic..

[ltdmstr]

9 lb.

[fieryotaku]

5 minutes ago, ltdmstr said:

9 lb.

Thanks!!  I wonder why they recommend a heavier spring?

Edited May 26, 2020 by fieryotaku

[Sarge]

3 minutes ago, fieryotaku said:

Thanks!!  I wonder why they recommend a heavier spring?

I think guns are inherently more reliable with heavier springs up to a point. 

[fieryotaku]

2 minutes ago, Sarge said:

I think guns are inherently more reliable with heavier springs up to a point. 

interesting this is going to be a range/home defense gun so I may also order a 11-12 pound spring and test reliability

[Sarge]

2 minutes ago, fieryotaku said:

interesting this is going to be a range/home defense gun so I may also order a 11-12 pound spring and test reliability

I meant that from a manufacturer standpoint mostly. Guns can be, and often are, 100% reliable with lighter spring setups. I have an Open gun that will run fine with a 7lb spring but if it gets even a little dirty it will start failing to feed 100%. With an 8lb spring I can shoot it for weeks with zero problems. And STI used to ship with 9 or even 10lb springs.

[bcane98]

I’ve been running the stock 12# spring in my DVC3 shooting Blazer 124gr 9mm, and runs like a sewing machine with my hand loads; CFE pistol 5 gr, 1.55 OAL.  
 

What magazine release is on yours?  I’ve seen a few with that similar design.

[MikeBurgess]

they ship with heavier springs for reliability, competition shooters tune springs for performance, 

there is more to it than just the recoil spring weight, there is also how hard to you hold the gun, what is the main spring weight, what is the shape of the firing pin stop, how much does the slide and optic weigh, what does the frame grip and light weigh, what do you lubricate the gun with (grease, oil, heavy, light), how tight is the action. 

 

so the question becomes what is your goal and how do you want to get there?

[mvmojo]

I run a 7 lb. Spring with 147gr Xtreme 9mm bullets over 3.8gr WSF at 1.15 OAL in an STI SteelMaster.  Runs reliably with soft, flat shooting.  I tried a 6 lb spring & it ran fine but the dwell time of the slide return was noticible and weird! 

[Aircooled6racer]

Hello: I would use a 10lb ISMI recoil spring or check the brand of spring you are using and make sure it is what the package says. Not all spring are as marked. Are you using defense ammo? If so I would use a 11 pound spring and test for at least 500 rounds to make sure it goes bang all the time. Thanks, Eric

[mvmojo]

I use Wolff springs in my 2011 SteelMaster.  I've checked them with a spring gauge and found them to be within specs.  But, I'm referring to springs used in a competition gun, not a self defense carry gun.  For a carry gun I use factory springs.  FWIW, 500 rounds is a pretty stringent test, statistically more than needed to get a greater than 95+% confidence level.  But when your life is at stake, the larger the sample size the better!

[Yeti]

Get conventional Wolff 10, 11 & 12# recoil springs.  I'd start with testing 11# since you have RD slide  mounted and shoot factory 115/124gr.