Brandon04GT Posted June 12, 2017 Share Posted June 12, 2017 (edited) So I have an STI 2011 Tactical DS 5.0 in 9mm. It came from the factory with a 10lb recoil spring and 15lb mainspring. I had since changed the MS to a 17# and have been experimenting with different recoil springs. I had since tried a 12# (would barely cycle), 11# (shells would just dribble out the ejection port) and a 10# (so far has been the best one albeit the slide is still cycling slow) I had put about 600 rounds thru it before sending it back to STI for unrelated reasons which resulted in them refinishing the slide. A few days ago I put it 400 rounds thru it. Shells were ejecting 1-3' away and after a few hundred rounds, the slide really began to feel a bit slow. I am wondering what other spring combos I can try to increase performance while maintaining durability and reliability. Althought I was shooting Remington UMC and Blazer Brass 9mm which seems to be loaded on the lower side, I am setting this gun up for "HD/Duty" instead of gaming so I may also be shooting some stouter HD rounds. So far I am thinking of either: 1. Replace the mainspring with a 15# and hope I don't get light strikes. 2. Replace the mainspring with a 15# and go up to an 11# recoil spring to help with speed. 3. Keeping the existing 17# mainspring/10lb recoil spring combo and shooting it more to see if the gun breaks in further and smooths out. I'm guessing since I have a full rail version with a more meaty/heavier slide, that doesn't quite help either. Thanks Edited June 12, 2017 by Brandon04GT Link to comment Share on other sites More sharing options...
jcc7x7 Posted June 12, 2017 Share Posted June 12, 2017 17 MS 8-9 Recoil Spring 7lbs works great BUT if you grip softly it won't cycle the rounds out of the mag, so for a duty gun wouldn't be my choice Link to comment Share on other sites More sharing options...
Aircooled6racer Posted June 12, 2017 Share Posted June 12, 2017 Hello: 17lb ISMI mainspring and a 9lb ISMI recoil spring works great. Make sure you keep it well oiled as well. I used Mobil 1 15W50 for summer and 0W20 for winter. Thanks, Eric Link to comment Share on other sites More sharing options...
Brandon04GT Posted June 13, 2017 Author Share Posted June 13, 2017 Thanks for the responses. I am thinking about trying a 9mm recoil spring, but would't that slow my slide down even more on the forward stroke? Link to comment Share on other sites More sharing options...
Jim Watson Posted June 15, 2017 Share Posted June 15, 2017 Just speculating, how about one of the contoured low resistance hammers like the Optimum or Cammer? Link to comment Share on other sites More sharing options...
mike4045 Posted June 15, 2017 Share Posted June 15, 2017 9# spring and minimum 17#ms. I use a 10# in my guns but I run a heavier load. It run wwb 115 just fine. I would check mag feed lips for burrs. It could cause rounds to drag coming out of the mag slowing down your slide. Last year I picked up guide rod that had a few high ridges slowing the spring movement. I found that by accident when detail stripping gun. Playing with spring noticed it was really tight to the rod in a couple spots. Link to comment Share on other sites More sharing options...
Ocd666 Posted June 15, 2017 Share Posted June 15, 2017 I've run a 15# ms for 2yrs no light strikes using Cci federal mag tech and S&B primers. I've used 9,8,7 recoil springs settled for the 7# variable Wolfe with shock buff as my loads are only 105PF. Put about 5000 rounds through it. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted June 15, 2017 Share Posted June 15, 2017 Switch to Brian's Slide Glide - it will really smooth out your gun .... Link to comment Share on other sites More sharing options...
Bob DuBois Posted June 17, 2017 Share Posted June 17, 2017 Have two Eagles and a Trojan in 9mm. Love um. All three have 15 pound recoil springs along with my 40 and 45 guns. Never had a light hit using Winchester Primers. Trojan has about 30.000 rounds with the same spring runs Great. Put the 10lb recoil spring back in or a 9lb along with 15lb main, Put a little Mobil 1 in there when you change the spring it will run. Link to comment Share on other sites More sharing options...
spininfirec Posted March 7, 2018 Share Posted March 7, 2018 Ive messed with a lot of different springs. I run roughly 125 pf with 147 gr fyi. Ive had too high of a main spring, up to 19lb and the gun wouldnt even run my 125 pf loads due to the mainspring slowing down the slide. I run a 13lb now with a 7lb recoil spring. Ive tried as low as 5lb but the slide had too much lag and tossed that asap. The 6 lb felt nice but it was a tad slow to shoot fast and clean. Not a good thing but I could be a little more lacks with my grip. I'm working up now trying 8lb soon. But I have run a 7lb on a 5" and 6" slide both. Ive also had gun issues and required heavier springs. Ive gotten my guns cleaned up and could run any spring combination reliable. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now