Edmooberry Posted September 25, 2015 Share Posted September 25, 2015 Gents, I just bought some MBX 140's from shooters connection for my 9mm Cheely. The two I have tested so far ran great up until the last round. They would not feed the last round and had a failure to feed every time. The follower seems to be cocked upwards at kind of a steep angle. I have a feeling this didn't help the issue, but I have no experience with these mags. Any thoughts? Link to comment Share on other sites More sharing options...
outerlimits Posted September 25, 2015 Share Posted September 25, 2015 Swap out guts for TTI stuff. End of issue. Link to comment Share on other sites More sharing options...
jlat32 Posted September 25, 2015 Share Posted September 25, 2015 Swap out guts for TTI stuff. End of issue. Will this still hold 24 rounds with the TTI guts? Link to comment Share on other sites More sharing options...
trouble Posted September 25, 2015 Share Posted September 25, 2015 Mine only holds 23 with the TTI guts but it's 100% reliable. Link to comment Share on other sites More sharing options...
Paul-the new guy Posted September 25, 2015 Share Posted September 25, 2015 Is it locking the slide back with a round still in the mag or just not feeding the last round? Link to comment Share on other sites More sharing options...
jeff1383 Posted September 25, 2015 Share Posted September 25, 2015 Swap out guts for TTI stuff. End of issue.Aren't these supposedly tuned mags to begin with? Link to comment Share on other sites More sharing options...
ltdmstr Posted September 25, 2015 Share Posted September 25, 2015 Haven't used them personally, but several have told me they've had problems with them and the springs don't last very long. I have Grams internals in STI tubes with standard base pads and they hold 24 rounds easy and work 100%. Link to comment Share on other sites More sharing options...
AFguywhoshoots Posted September 25, 2015 Share Posted September 25, 2015 I have been running my 9mm 140's for the past 2 months and haven't had any issues with the stock spring and follower. Shoot a message to Adrian and see what he suggests. Link to comment Share on other sites More sharing options...
Maxximuss Posted September 26, 2015 Share Posted September 26, 2015 I haven't had any issues with my 140mm MBX mags in 9mm. How new is the gun? How new are the mags? What ammo/OAL/bullet are you using? I've encountered problems with several of my STI mags when they are brand new (or brand new guts), sometimes it feels like they need to break in too. I would recommend round nose bullets (124 or 147 grain) loaded to 1.160-1.165 OAL. Put a couple hundred rounds through it and see if it sorts itself out. Link to comment Share on other sites More sharing options...
Edmooberry Posted September 26, 2015 Author Share Posted September 26, 2015 I haven't had any issues with my 140mm MBX mags in 9mm. How new is the gun? How new are the mags? What ammo/OAL/bullet are you using? I've encountered problems with several of my STI mags when they are brand new (or brand new guts), sometimes it feels like they need to break in too. I would recommend round nose bullets (124 or 147 grain) loaded to 1.160-1.165 OAL. Put a couple hundred rounds through it and see if it sorts itself out. This very well could be the problem. Both the magazines and the gun are brand new. The gun only has about 100 rounds through it so far. I just asked the question because I've read good things about MBX reliability, but these have fallen short so far. And I am loading 147 gr xtremes at 1.15 oal. Link to comment Share on other sites More sharing options...
Maxximuss Posted September 26, 2015 Share Posted September 26, 2015 I am 90% certain that the issue is a break in. Many STI's aren't very reliable until about 500 rounds. They are very tightly built. I recommend using the break in process as described on Brazos Customs website http://www.brazoscustom.com/magart/0705.htm. Basically keep it well oil and don't clean it until after 500 rounds. You can't be too hard on a brand new STI, give it some time and it will run flawless. Link to comment Share on other sites More sharing options...
v1911 Posted September 27, 2015 Share Posted September 27, 2015 Also, be sure to load your mags to capacity and let them sit for a few nights. Link to comment Share on other sites More sharing options...
Nibbles Posted September 28, 2015 Share Posted September 28, 2015 (edited) First post, hello all. Maybe check your springs? I have two brand new MBX 9/38 140 mags; one feeds perfectly, the other pushes the last round up too high so that it jams on the edge of the chamber. I took them both apart, and it turns out that the trouble mag had a 170 spring instead of a 140. When swapped to a spring with proper length that mag now runs flawlessly as well. Edited September 28, 2015 by Nibbles Link to comment Share on other sites More sharing options...
Edmooberry Posted September 28, 2015 Author Share Posted September 28, 2015 Thanks Nibbles. I'll have to take them apart tonight and take a look. Link to comment Share on other sites More sharing options...
drewbeck Posted September 29, 2015 Share Posted September 29, 2015 You likely just need to close the feed lips a little bit. Basically the follower is putting slightly different pressure on the last round than a round would be putting on it if there was one below it and it's angling up more as it comes off the mag and hits the upper right side of the barrel. The MDX mags are solid and usually run excellent but metal will deflect when there is pressure, they get dropped, etc and this is something that everyone should learn to diagnose and fix if they want their mags to run reliably. It's nothing to worry about, it's just a maintenance item. Link to comment Share on other sites More sharing options...
drewbeck Posted September 29, 2015 Share Posted September 29, 2015 The lips could change literally .001 and the mag would go from reliable to failing to feed every last round. You just need to get them back under the threshold of where they become "too wide" and all will be good again Link to comment Share on other sites More sharing options...
rpm8300 Posted November 13, 2015 Share Posted November 13, 2015 I have new 170 and 140mm MBX mags with the same issues. Other than that they run extremely well. Link to comment Share on other sites More sharing options...
1911A12011 Posted November 24, 2015 Share Posted November 24, 2015 I use 170 MBX on my open guns and had no issues. Since your other MBX's works fine, then, I recommend you contact MBX (not shooters connection 'coz they will just let you contact MBX anyways) because they are marketed as tuned mags at $$$. You can request them to just send you new internals (spring and follower). If you still have issues, then just let them replace a brand new (real) tuned mags (avoid spending time and rounds on trial and error). Link to comment Share on other sites More sharing options...
tyler2you Posted November 25, 2015 Share Posted November 25, 2015 Had the same issue with my 140 and 170 9mm MBX mags. I bent the first coil forward a bit and now they run perfectly. Link to comment Share on other sites More sharing options...
mike_pinto Posted November 25, 2015 Share Posted November 25, 2015 I have been running MBX since they came out. The last two 9mm 140's I received had followers that were just a little wide in the back and causing the backside of the follower to stop short of top travel. I measured them against my old ones that work great and they were close to .0075 wider. It was making the follower rise in the front dramatically on the last round. I filed just a hair off each side of the rear of the follower and they are 100% perfect. Link to comment Share on other sites More sharing options...
Nibbles Posted November 25, 2015 Share Posted November 25, 2015 Would you mind posting the measurement of the ones that were correct? I'll have to check that, if only to satisfy my curiousity. Link to comment Share on other sites More sharing options...
mike_pinto Posted November 25, 2015 Share Posted November 25, 2015 The very back of the follower is .522 and the spot right before the step down is .520. This is consistent across all of mine.. Hope that helps Link to comment Share on other sites More sharing options...
sbo76 Posted November 26, 2015 Share Posted November 26, 2015 Check if there is any drag on your follower when it's inserted all the way. If it rubs take a few swipes on the back of the follower with a file and try again. Repeat until there is no drag. Don'the hack away at the follower. The file removes material fast. Link to comment Share on other sites More sharing options...
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