cheers623 Posted February 5, 2014 Share Posted February 5, 2014 My wife and I have been shooting USPSA for years. Been using my various STI .40 cal 2011s with no problems ever. I've tuned maybe 14-18 140mm magazines using the Dawson vids and tools, various spring and follower combos, and lots of different basepads. All with good effect and reliability as long as the ammo and gun were setup correctly. HOWEVER....I finally purchased a dedicated Limited gun to be my wife's. An STI Tactical in 9mm...there's the problem. The gun is fine, extractor tuned, ejection fine, feed ramp polished blended, chamber polished, breech face good to go, etc. It runs with no problems with the 126mm mags. BUT, with the 140mm mags loaded more than 17-18 rounds it has a nosedive failure to feed from the top round EVERYTIME. Dawson 9mm basepads, STI 9mm factory followers de-burred, 140mm STI springs, and polished/de-burred STI spacers. I've even tried the Hardy steel spacers. Same problem. Now, the load is not helping possibly. Her favorite load is Rainier 124gr hollowpoints, over Ramshot Competition, with COAL of 1.135". We've tried loading both longer and shorter and still get the exact same problem. So my question is...what can I do? Should we give up on the hollowpoints entirely and start with round nose profile? I'm skeptical because the nosedive is so pronounced I think it'll have the same problem regardless. Different followers, springs, etc? Any mag tuning gurus that specialize in 9mm 140 length mags? Most folks that shoot 9major use round nose bullets around here. I've tried bending the spring, 1 coil after the follower to add a nose-up bias on the springs...no luck. It just seems like the tapered wall cases curve too much after around 17-18 rounds in the mags. The mags will hold 21 rounds but never work with more than 17-18 in them. My wife is really disappointed. Any help is GREATLY appreciated. Cheers623 DVC Link to comment Share on other sites More sharing options...
yoshidaex Posted February 5, 2014 Share Posted February 5, 2014 Try a grams follower and spring combo. Link to comment Share on other sites More sharing options...
superdude Posted February 5, 2014 Share Posted February 5, 2014 Yes, that tapered case is a problem. It's also likely due to the mags not being designed as well as they should be to reduce the nosedive gap. You might have to use RN bullets, and if you do, the best ones are HARD, like FMJ and not plated bullets like Rainier. Plated bullets are soft and their copper plating isn't as slippery as we think. Hard bullets bounce off the feed ramp much better. Link to comment Share on other sites More sharing options...
Kingman Posted February 5, 2014 Share Posted February 5, 2014 Grams follower and spring. Then Buy SVI tubes. Link to comment Share on other sites More sharing options...
sandrooney Posted February 5, 2014 Share Posted February 5, 2014 I had a 9mm Edge, Grams followers and springs, stock spacers inside of STI mags. MGB 124 CMJ and it ran flawless. Link to comment Share on other sites More sharing options...
tjs375 Posted February 5, 2014 Share Posted February 5, 2014 Open the front of the feed lips about to about .370" and set the back to .365". I found that it lets the round sit higher in the feed lips and only uses the top third of the feed ramp. I use Grams springs and followers for Sti tubes, they just work. Link to comment Share on other sites More sharing options...
EEH Posted February 5, 2014 Share Posted February 5, 2014 (edited) I have a custom 6" sti with caspainslide, sti mags with grams springs and followers and SS spacer.They run great.You can buy SV mags and forget about spacers,,my sv tubes will run 9mm hollow point without spacers.. Next match get one of the open guys to let you borrow a sv mag and give it a try Edited February 5, 2014 by EEH Link to comment Share on other sites More sharing options...
lcs Posted February 5, 2014 Share Posted February 5, 2014 GRAMS 9mm followers (they come with springs), spacers, and you should be good to go. OAL 1.160 to 1.165 with spacers. All I use is 115 JHP and they run 100%. If the JHP or 121 IFP hang once in awhile on the feed ramp--just shorten the OAL a touch until they run. Link to comment Share on other sites More sharing options...
jstagn Posted February 5, 2014 Share Posted February 5, 2014 try the dawson pads on the mags that work, then you will know if its the mag. Link to comment Share on other sites More sharing options...
EngineerEli Posted February 5, 2014 Share Posted February 5, 2014 I have a new 9mm eagle for 3gun/limited minor, and I put the grams guts ss spacer and Dawson pad on one 140 mag, I have only tested it with 5-10 rounds, I'll have to try mine with a full load before a match. I'll be watching this thread... Also, are the rear spacers supposed to rattle around until the magazine is loaded or is there some way to affix it to the mag? Link to comment Share on other sites More sharing options...
BrianATL Posted February 5, 2014 Share Posted February 5, 2014 They should rattle Link to comment Share on other sites More sharing options...
troupe Posted February 6, 2014 Share Posted February 6, 2014 What recoil spring and hammer spring are you running ? Link to comment Share on other sites More sharing options...
Sarge Posted February 6, 2014 Share Posted February 6, 2014 I have a new 9mm eagle for 3gun/limited minor, and I put the grams guts ss spacer and Dawson pad on one 140 mag, I have only tested it with 5-10 rounds, I'll have to try mine with a full load before a match. I'll be watching this thread... Also, are the rear spacers supposed to rattle around until the magazine is loaded or is there some way to affix it to the mag? I don't like anything to rattle, whether it be a car or a magazine. I rough up the back of my spacers and silicone them into the mags. They pretty much last all year. When one comes loose I will take them all apart and resilcone them all. Link to comment Share on other sites More sharing options...
EngineerEli Posted February 6, 2014 Share Posted February 6, 2014 I tend to agree, I hate it when parts fit loose. Exactly what type of 'silicone' do you use? I may have to give it a try. Think it would work with the plastic sti spacers too? Link to comment Share on other sites More sharing options...
424D57 Posted February 6, 2014 Share Posted February 6, 2014 One more vote in case you don't yet have sufficient confidence in the replies here- Tune the tube per the Dawson video, and get Grams 11 coil 9mm guts. We use the STI tubes/hardy spacers/grams guts for 9 minor and 9 major 2011s up to 23-24 rounds in the mag with no problems. -424D57 Link to comment Share on other sites More sharing options...
cheers623 Posted February 6, 2014 Author Share Posted February 6, 2014 Thanks for all the replies. I guess I'm getting Grams stuff. I already tuned the mag bodies and feedlips per the Dawson video but, I've been trying to ge the STI guts and springs to work. Guess that's only going to fly for less than 18 rounds. The 126mm mags run no problem. It's just the 140mm with all STI parts and Dawson base pads that are giving me problems. Thanks for the input guys! Cheers623 DVC Link to comment Share on other sites More sharing options...
450AK Posted July 19, 2014 Share Posted July 19, 2014 Guys I'm a tig welder by trade that owns a gun store. I weld the stainless spacers to the mag bodies and they never come loose and I polish them when they are done so they look like they are milled from one piece. Do do this for 25 dollars per mag if anyone is interested. Link to comment Share on other sites More sharing options...
DougCarden Posted July 19, 2014 Share Posted July 19, 2014 If that doesn't clear it up then look at your feed ramp...... DougC Link to comment Share on other sites More sharing options...
Aircooled6racer Posted July 19, 2014 Share Posted July 19, 2014 Hello: Set the feed lips to 0.357" front to back. Use Hardy spacer and Grams 9mm follower and spring. The Dawson follower/spring combo works well also. Load to 1.150" OAL and use a alb ISMI recoil spring and 17lb mainspring. Thanks, Eric Link to comment Share on other sites More sharing options...
troupe Posted July 20, 2014 Share Posted July 20, 2014 Thanks Eric, you are the only person that mentioned the recoil spring and mainspring. I thought I had fallen on deaf ears. Tommy Roupe Link to comment Share on other sites More sharing options...
Knp1288 Posted July 20, 2014 Share Posted July 20, 2014 Be keen to know what the outcome is. I recently had my own STI mag nightmares after converting to 357 Sig. 126mm tubes with Grams guts just didn't work. Nosedive on 1st and 2nd round yet they worked fine in a 140mm tube. Link to comment Share on other sites More sharing options...
Desmo412 Posted July 20, 2014 Share Posted July 20, 2014 I actually had some nose dive problems with a full mag also on my 9mm open STI. I traced the problem to the ejector pushing down on the rim of the case. When the round got pushed forward towards the chamber, it would flip downwards and stick on the bottom of the feed ramp. I relieved the bottom of the ejector and haven't had problems since - using 115 JHPs at 1.165" Link to comment Share on other sites More sharing options...
Tino2212 Posted July 20, 2014 Share Posted July 20, 2014 I also had a nosedive problem with my mags with grams guts switched to arredondo springs / spacers / and followers never had a problem anymore . Link to comment Share on other sites More sharing options...
oak hill Posted July 20, 2014 Share Posted July 20, 2014 I actually had some nose dive problems with a full mag also on my 9mm open STI. I traced the problem to the ejector pushing down on the rim of the case. When the round got pushed forward towards the chamber, it would flip downwards and stick on the bottom of the feed ramp. I relieved the bottom of the ejector and haven't had problems since - using 115 JHPs at 1.165" Good point, this is often overlooked but with the long ejector often times a problem. Link to comment Share on other sites More sharing options...
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