gerritm Posted June 15, 2020 Share Posted June 15, 2020 I have a brand new STI 170mm mag that I can't seem to get to run consistently. No spacer style. Will work 1 time then have a feed problem next. Usually 10 or 12 rounds in. Checked and adjusted the feed lips to specs. They were off from the factory slightly. Was sketchy with all stock guts. Changed to grams spring and follower, same. Changed to TTI basepad, spring, & follower, same results. Last malfunctions was on a classifier about 13 rounds in with the TTI stuff. MBX 170 mag & my STI 140mm mags all run fine. Strange thing with this mag. I load with a Lula loader. All my other mags the loader goes all the way down and load fine and is loose on the mag body. This mag the loader gets tight when you press down and the base sticks on the mag body and I have to pull the loader up slightly and hold the mag to load the next round. Seems strange that that would be that tight and would happen. I don't have another 170 STI mag to check the loader on and all my friends have the old gen mags. Any ideas? gerritm Link to comment Share on other sites More sharing options...
zzt Posted June 15, 2020 Share Posted June 15, 2020 You have to remove material from the yoke area of the Lula if you want to use it with STI Gen 2 mags. A minute with a Dremel or a file will take care of that. Don't know if this will solve your problem or not. Take a look at the Atlas video for tuning STI Gen 2 mags. I didn't have to do that with my 140s, but a buddy did. Link to comment Share on other sites More sharing options...
gerritm Posted June 15, 2020 Author Share Posted June 15, 2020 Glad to know it is normal with the Lula. I have the Dawson tuning kit and have done that already. Just wasn't sure if that neck area of the mag was that fat and it was normal. gerritm Link to comment Share on other sites More sharing options...
Furrly Posted June 15, 2020 Share Posted June 15, 2020 Dump the mag get an mbx or svi.. I could never get my STI 170 mag to run reliably even though it was tuned by atlas. Link to comment Share on other sites More sharing options...
NOSHMJ Posted June 15, 2020 Share Posted June 15, 2020 I gave up on all my STI mags and bought MBX. Link to comment Share on other sites More sharing options...
gerritm Posted June 15, 2020 Author Share Posted June 15, 2020 Thinking that might be the next step. When I had my DVC open 9mm the STI mags all ran great, but I had issues with the MBX mags, so I have a history of them working. That was back when MBX first started on the market. gerritm Link to comment Share on other sites More sharing options...
zzt Posted June 15, 2020 Share Posted June 15, 2020 I run MBX mags for USPSA. I do have three STI Gen 2 21 round mags. I replaced the springs, followers and base pads with TTI stuff and they run great, as in 100%. I mainly use them for Classifiers with a mandatory mag change, or any time I have to drop a mag in dust or mud. Link to comment Share on other sites More sharing options...
gerritm Posted June 15, 2020 Author Share Posted June 15, 2020 (edited) Same here with the STI 140's for classifiers and dropping in the sand. This is my backup 170. Ran my 170 MBX all day with 140 STIs with no problems. I have run it in practice after changing the guts/basepad to TTI and of course it worked, so last stage was a classifier Hi-Jinx, I figured I would try it on the clock and it failed . Shot the first 6 rounds and moved to 2nd position, shot 1 and jammed. We shoot 3-gun & have had a couple of all pistol 50 plus jungle runs or bay stages and nice to have plenty of rounds. Maybe my CK just doesn't like it. gerritm Edited June 16, 2020 by gerritm Link to comment Share on other sites More sharing options...
Glock17open Posted June 22, 2020 Share Posted June 22, 2020 (edited) On 6/15/2020 at 11:22 AM, NOSHMJ said: I gave up on all my STI mags and bought MBX. Same, save yourself some frustration. I use my syti mags for practice. So I can practice feed issues and gun stoppage problems. I don't have those problems with mbx. Edited June 22, 2020 by Glock17open Link to comment Share on other sites More sharing options...
Aircooled6racer Posted June 23, 2020 Share Posted June 23, 2020 Hello: try some TTI springs and followers and open up the feed lips to 0.357" front to back. Thanks, Eric Link to comment Share on other sites More sharing options...
gerritm Posted June 23, 2020 Author Share Posted June 23, 2020 9 hours ago, Aircooled6racer said: Hello: try some TTI springs and followers and open up the feed lips to 0.357" front to back. Thanks, Eric Did that already. Tried TTI springs & followers, and tuned the feed lips, same results with Grams guts. Last time it failed in a match it had the TTI guts. Guessing this gun doesn't like STI 170mm mags. 140's run fine. Will just get another MBX. gerritm Link to comment Share on other sites More sharing options...
Cam73 Posted June 23, 2020 Share Posted June 23, 2020 Did you squeeze and measure the tube as shown in the Atlas videos? https://atlasgunworks.com/atlas-gunworks-sti-2011-magazines/ Could possibly explain some of the stoppages and why the Lula Loader does not fit the tube. Link to comment Share on other sites More sharing options...
BadShot Posted June 23, 2020 Share Posted June 23, 2020 Make sure that it has the proper STI follower. One of mine had the previous generation in it, wouldn't work at all. Link to comment Share on other sites More sharing options...
Aircooled6racer Posted June 23, 2020 Share Posted June 23, 2020 Hello: You set the feedlips to 0.357" front to back? Thanks, Eric Link to comment Share on other sites More sharing options...
gerritm Posted June 23, 2020 Author Share Posted June 23, 2020 (edited) 1 hour ago, Aircooled6racer said: Hello: You set the feedlips to 0.357" front to back? Thanks, Eric I have the Dawson tuning kit and set them per the Atlas video, but will have to check for sure. They were off from the factory. 4 hours ago, BadShot said: Make sure that it has the proper STI follower. One of mine had the previous generation in it, wouldn't work at all. Tried 3 different followers/spring combos including the original never worked right. 4 hours ago, Cam73 said: Did you squeeze and measure the tube as shown in the Atlas videos? https://atlasgunworks.com/atlas-gunworks-sti-2011-magazines/ Could possibly explain some of the stoppages and why the Lula Loader does not fit the tube. Did not squeeze the tube others have said this is common to have to open up the Lula slightly to fit. Really don't know for sure. If the tube is that far out pretty sure I don't want to use it and will put in my practice bag. Should never be a reason to do this to a brand new mag. As a side note I have used many STI mags including older 170's with the shim and so has my son with great success. This is my first 170 new gen. gerritm Edited June 23, 2020 by gerritm Link to comment Share on other sites More sharing options...
Aircooled6racer Posted June 24, 2020 Share Posted June 24, 2020 Hello: Another thing to look at is the inside of the tube. Look at the welds and make sure there is not a spot that has a weld booger that is grabbing the case. Thanks, Eric Link to comment Share on other sites More sharing options...
gerritm Posted June 25, 2020 Author Share Posted June 25, 2020 20 hours ago, Aircooled6racer said: Hello: Another thing to look at is the inside of the tube. Look at the welds and make sure there is not a spot that has a weld booger that is grabbing the case. Thanks, Eric Checked everything over. Feed lips are good. No problems that I can see internally. I have a new gen 140mm and the Lula is tight loading that also. Made sure the follower is smooth. Ran all my dummy rounds thru it and they ejected smoothly. I am shooting a match this weekend, if the rain holds off. Will test at the range again before and if it runs then try it in the match. gerritm Link to comment Share on other sites More sharing options...
sam_b Posted June 25, 2020 Share Posted June 25, 2020 At this point just call/email STI and explain your issue, I bet they send you a new mag. Link to comment Share on other sites More sharing options...
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