STI Reliable 9mm single stack on 10 round mags at PF 135, possible?

Discussion in 'Competition 1911's' started by johnmyster, Apr 18, 2020.

  1. johnmyster

    johnmyster Well-Known Member Supporting Addict

    152
    Feb 4, 2020
    So, not experiencing this in my 45 guns. I even had a few 45 kimbers running reliably with 200gr swc at 145 pf. Just frustrated because it would be nice to have a 9mm option. Seems like the gun is barely on the edge of running. So I'll toss all the variables at the experts. What are my goals? Reliable feeding, reliable slidelock, etc.

    I have a Trojan that just came back from STI to try and clear up infrequent nozedive jams. Aside from that issue, gun was good. My reloads are a 135gr coated at 1000 fps at 1.125". I'm sure that coated bullets at low PF are THE contributing factor...that FMJ and more power would help. Current recoil spring is a 10# conventional, measures 9.5# on the tester. Current mainspring is 17#.

    STI gunsmith Ricky was a pleasure to talk with. He fit a new barrel. Seems some of the earlier guns had steeper ramps and were cut too far from the magazine. I don't doubt that it ran fine on their range. They also sent me a Tripp mag and suggested I switch from my ETMs, which I have.

    It now takes a tap on the back of the slide 1/10 shots. Better than a nozedive jam but not cool. I also lost reliable slidelock. Both issues point to short stroking of the gun.

    Experts, what would your approach be?

    Reloads: I am experimenting at 1.15 oal. That's a frustrating move because I'll have to load shorter for other guns, even though those only represent a small volume of shooting. I've also gone up a tenth of powder, to try and get slidelock back, and perhaps tolerate a stiffer recoil spring.

    Springs: It seems like I need more spring for feeding, but that would hurt slidelock even more. Should I go down even further on mainspring to try and get some slide velocity? I've never had light strikes on Remington primers.

    Extractor: STI says they reset my extractor. I had it set light to help feeding. Perhaps it's now too tight to feed smoothly?

    Technique: Keep my thumbs off the slide.

    Other: I have an EGW raised mag catch on hand. Perhaps that would help with the feeding aspect? The trip mags have some clearance to the ejector.

    Other, other: Buy a higher end gun?

    End rant. Thanks for reading/responding.
     
  2. bladeandbarrel

    bladeandbarrel ISO The Very Best 1911's Supporting Addict

    890
    Apr 6, 2019
    In my experience, the metal follower ETM mags will cure almost any 9mm if you are looking for 10rd capacity. in a 5" 9mm I like a 19# hammer spring and 10-11# recoil spring. Extractor tension should hold an empty case at 90 degrees with less than 10 thou of cam out and the hook should lightly kiss the inside of the extractor bevel when feeding but not leave a gouge in the case during the firing cycle.
     

  3. fieldgrade

    fieldgrade resident crank

    Mar 13, 2017
    Only trouble with ETMs in 9mm is they stand taller and insert farther than others. I’ve bent ejectors in two Colts with them due to the mag contacting the ejector.
     
  4. David R

    David R Well-Known Member

    384
    Oct 7, 2018
    I can't help much. I shoot a Dan Wesson PM-9.

    Stock 10 lb recoil spring and stock main spring.
    115 grain HAP @ 1050 fps. PF 120.7
    Zero problems feeding or ejecting. My wife shoots this gun and does not hang on to it near as tight as I do. It works perfect for her too.

    I have a Springfield 4" RO Champion. It will shoot those loads for me, but not her.

    I load these in batches of 1500. We both shoot Bullseye.

    David
     
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  5. zipper046

    zipper046 Well-Known Member

    Dec 28, 2013
    sounds like you may have a few issues going on....

    1) Nose Dive....I've found (in my own experience) that different mag's may cause this. Some mag's have mag catch holes (cutouts) slightly higher or lower than others....case in point: DW mag's in my CCO run fine, load fine, lock back fine....Wilson mag's sometimes nosedive the first round when loading from slide lock HOWEVER with a SLIGHT upward push on the bottom of the mag and then releasing the slide - the round feeds perfectly...it seems it sits a TAD LOWER which was causing the first round to hit too low on the feed ramp. I'd try a few different mag's and see if that helps...2nd step is the feed ramp recut, but it seems you had this done already, so I'd try some different mags

    2) Slide Lock issue....refer to #1 above....the same thing has occurred with mag's.....since some mag's sit SLIGHTLY LOWER than others, I've found the one's that sit lower sometimes don't allow the follower to rise enough to engage the slide lock....the other option is to fit a new slide stop...measure the "nub" that the follower engages and make sure it is wide enough to engage the follower but without impeding the follower (may have to use a few swipes with the file with a new one...or not...)

    If you haven't installed the EGW raised mag catch yet...I'd try that...it may help resolve your issues....

    I'm no whiz bang 'smith....but have had similar issues that I've worked through with the above....YMMMV...
     
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  6. johnmyster

    johnmyster Well-Known Member Supporting Addict

    152
    Feb 4, 2020
    Thanks all. David, thanks for letting me know that low PF is possible with springs in this ballpark.

    For the record, the new barrel and mags seem to have resolved nosedive. Increased OAL certainly won't hurt.

    After checking, IMO, extractor tension is too tight. Loaded round will not shake loose at all. Extractor claw bottoms out on interior of tunnel with no brass in place. I will adjust this, which may free up some momentum on the last part of the ride home.

    The tripp mags have pretty substantial engagement with the slide catch nub and the followers don't rock/wiggle laterally. They do have adjustment of the engagement tab, which I can approach. However, I'm still inclined to suspect the slide lock is short stroke issue unless extractor cleans up the feeding cycle.

    For all the sherlocks out there, I get that I massively did myself a disservice by changing too many things at once. Barrel, OAL, mags, etc.

    IMG_2984.JPG
     
  7. zipper046

    zipper046 Well-Known Member

    Dec 28, 2013
    LOL...we've all been there brother!! LOL...
     
  8. bladeandbarrel

    bladeandbarrel ISO The Very Best 1911's Supporting Addict

    890
    Apr 6, 2019
    Whip out your file!
     
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  9. jcc7x7

    jcc7x7 Well-Known Member

    Nov 2, 2019
    I've run 9mm 1911 for years. Some can be finicky
    General rule of thumb with 9's for me have been load long as your chamber/mags will allow.
    I run mine at 1.150 with a Bayou TC bullet.
    Tripps, Wilson or CMC mags which ever your gun likes.
    Mine will reliably run with all three
    Fresh recoil springs often 5k, I run 8 or 9 lbs Wolff variables
    19lbs MS
    Check your crimp on your reloads via plunk test, also your OAL with the plunk test.
    Check Extractor tension
    FWIW
     
  10. johnmyster

    johnmyster Well-Known Member Supporting Addict

    152
    Feb 4, 2020
    Thanks all.

    I'm 100% plunk test on a few different barrels at 1.150" OAL. My CZ 75 won't be happy, but that doesn't get shot much anyhow.

    Extractor tension lightened. I fit the EGW raised catch and adjusted all Tripp mags so that they just begin to touch the catch with 1 round still in the magazine.

    If all sorts itself out, I may back down on the load eventually. For now, it would be nice to run on a 10# recoil spring, but "fear" I may be buying some 11 and 12# if return to battery needs the extra umph and slidelock is sorted.
     
  11. Rick McC.

    Rick McC. Well-Known Member

    688
    May 3, 2013
    This!

    I reviewed a Wilson ACP a few months ago that came with a couple of the new design 9mm ETMs. They fed anything, and the brand new pistol ran without a single malfunction for as long as I had it, which was over 500 rounds fired without cleaning or re-lubing.

    So, I bought four of them from Wilson. I checked some of the cheaper mag places first, but none had any of the new design ETMs; they were all the composite follower ones.

    I loaded all four of the new mags up, took them to the range the next morning, and they functioned flawlessly, including feeding hollow point ammo in a 15 year old Wilson Professional that had never fed HP ammo successfully before. They’re the only 10 round 9mm 1911 mags I’ve ever owned that would feed the top round in a full mag that smoothly and reliably.

    They really are that good, and a big improvement over the previous ones.
     
  12. bladeandbarrel

    bladeandbarrel ISO The Very Best 1911's Supporting Addict

    890
    Apr 6, 2019
    Yep. But people are too stubborn to listen. LOL
     
  13. Rick McC.

    Rick McC. Well-Known Member

    688
    May 3, 2013
    I’ll bet the new design ones won’t.

    My 10 year old ETMs were a bear to seat when the slide was forward, but these new ones seat nicely.
     
    Last edited: Apr 19, 2020
    fieldgrade likes this.
  14. fieldgrade

    fieldgrade resident crank

    Mar 13, 2017
    I wish I knew this last night when I ordered six Dawson Competition mags (Metalforms), although I have run them before and they run good. Still I would have liked to try these new Wilsons. I might yet.
     
  15. Rick McC.

    Rick McC. Well-Known Member

    688
    May 3, 2013
    I’ll bet your first round feed and FTRB issues would disappear with a 13# recoil spring.
     
  16. Rick McC.

    Rick McC. Well-Known Member

    688
    May 3, 2013
    Words to live by!
     
  17. johnmyster

    johnmyster Well-Known Member Supporting Addict

    152
    Feb 4, 2020
    The Wilsons aren't bad...I currently have ten (for sale) and seven tripps. I can say that the Wilsons had nozedive more often and more severely than the Tripps in the first three rounds. Five of my wilson mags are new style. I get that mags are a part of the "weapon system." The rest of the system needs to be agreeable for any mag, and that's what I'm trying to sort out.

    I can confirm that the Wilsons sit higher in the gun, and that the EGW raised catch buys most of that height back with the Tripp mags.

    Rick, thanks. Next range trip I'll experiment with 12-13# recoil springs. Even if 10# gets it done, once the spring starts to set and the gun is dirty, does that put me blowing match stages vs running a little extra spring. That's the exact scenario that made me build a spring tester a few months back.
     
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  18. bladeandbarrel

    bladeandbarrel ISO The Very Best 1911's Supporting Addict

    890
    Apr 6, 2019
    metal follower or polymer follower wilsons?

     
  19. johnmyster

    johnmyster Well-Known Member Supporting Addict

    152
    Feb 4, 2020
    I have some of both, but metal were the ones I was using.
     

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