joecichlid Posted October 30, 2008 Share Posted October 30, 2008 Last week I was trying to help a friend out with his magazines and we ran into a problem with the rounds nose diving into the feed ramp on his STI Open gun. After looking into the matter his mags are not holding the nose of the rounds high enough. STI 170mm factory tubes, Grams spring and follower with Dawson +1 pad is the set up we are working with. The odd thing is the very same spring and follower in my tubes hold the nose of the round up high enough. With the only difference being the mag tubes I am guessing the issue has something to do with the feed lips. Any ideas what could be causing this or how to correct it? Thanks in advance. Joe W. Link to comment Share on other sites More sharing options...
JThompson Posted October 30, 2008 Share Posted October 30, 2008 9MM, 38S or SC? Link to comment Share on other sites More sharing options...
joecichlid Posted October 30, 2008 Author Share Posted October 30, 2008 .38 Super, sorry I forgot to include that. I blame it on the late hour. lol Joe W. Link to comment Share on other sites More sharing options...
benny hill Posted October 30, 2008 Share Posted October 30, 2008 Feed lips at about .355. Try a ISMI mag spring. Link to comment Share on other sites More sharing options...
CJDOUBLETAP Posted October 30, 2008 Share Posted October 30, 2008 Feed lips at about .355. Try a ISMI mag spring. yep. Link to comment Share on other sites More sharing options...
joecichlid Posted October 30, 2008 Author Share Posted October 30, 2008 Benny, the lips are at 0.355 at the rear but 0.365 at the front. I tried springs from three different makers (didn't have any ISMI) and the rounds nose dived with all springs. Joe W. Link to comment Share on other sites More sharing options...
HSMITH Posted October 31, 2008 Share Posted October 31, 2008 Could be a number of things, feed lips are but one small part of what it takes for the magazine to run. Check the OAL and make sure it isn't any longer than 1.25", if it is they will drag on the front of the mag and nosedive badly. 1.24" is better. See if it will run with 3 rounds, 5 rounds, 7 rounds, and so on, that will give you a better idea of where the problem lies. Link to comment Share on other sites More sharing options...
joecichlid Posted October 31, 2008 Author Share Posted October 31, 2008 HSMITH, I can't swear but I want to say the ammo is loaded to 1.240 or very close to it (not my ammo). We played around with the mag and it would choke randomly between one and 27 rounds. It choked a time or two stripping the first round out of the mag if I recall. There is no consistancy to when it does it sad to say. Joe W. Link to comment Share on other sites More sharing options...
HSMITH Posted October 31, 2008 Share Posted October 31, 2008 Well, sounds like the mags are pretty bad off. Have you guys run it with any other mags to eliminate any contribution to the problems that the gun might be providing? I have found all sorts of gun problems troubleshooting mags that 'don't work'. If it runs with other mags I would suggest sending the problem mags out to your favorite gunsmith or mag tuner, it generally isn't fast or cheap but it beats having a $3000 bolt action club..... Link to comment Share on other sites More sharing options...
joecichlid Posted October 31, 2008 Author Share Posted October 31, 2008 I tried the mags in question in my gun and they ran fine so I think it is down to something with my friends gun. I will have him try one of my mags which I know works 100% in my gun and see if it chokes again. Thanks for the advice. Joe W. Link to comment Share on other sites More sharing options...
HSMITH Posted November 1, 2008 Share Posted November 1, 2008 Make sure the grip is ALL the way up on the frame and tight. Check the ejector to be sure the underside is relieved and does not contact the top round in the mag. Swap mag catches with your gun. After the basic stuff if it still doesn't run you will probably need to get the gun to a Smith...... Link to comment Share on other sites More sharing options...
joecichlid Posted November 3, 2008 Author Share Posted November 3, 2008 Get the gun to "a" Smith...... Don't you mean get the gun to "H"SMITH? lol Just teasing. Thanks for the advice, I will pass the info onto my friend and see if it helps. Joe W. Link to comment Share on other sites More sharing options...
Ed Robinson Posted November 5, 2008 Share Posted November 5, 2008 I had the same problem with my Para 38S. Finally determined the small semi rim was "hanging" on the rim below it, causing the top round to nose down. 38 Supercomp brass solved the problem. All I had to do was adjust the extractor a very slight amount for 100% ejection. With a Aftec ext. I wouldn't have even had to do that. At least get a handfull of 38SC and try them before doing anything else. Link to comment Share on other sites More sharing options...
chuckbradley Posted November 5, 2008 Share Posted November 5, 2008 When we shot 38 super way back when we also made sure we loaded the ammo long enough to keep the rims from locking on each other. To do this we always loaded our 125FMJ zero bullet to 1.255. This length changes for bullet shape. That bullet had a real pointy nose. I know there is some conflicting info here. Bottom line is that one fix will not work for every set of varibales, Gun, Mags, Mag components, Ammo, Ammo Components etc. You have to find what works best for your set up. When you do dont switch anything. Link to comment Share on other sites More sharing options...
joecichlid Posted November 5, 2008 Author Share Posted November 5, 2008 Chuck, I even went so far so to try my ammo in the mags and they kept nosing down although we didn't fire them out of the gun. I run .38 Super brass topped with an MG 121 IFP seated to 1.250-1.255 OAL. But I am with you 100%, if the gun is running great don't dink with it. lol Keep the beast cleaned, lubed and ready to go changing the springs every so often so that you keep things consistant. Joe W. Link to comment Share on other sites More sharing options...
james57 Posted December 10, 2008 Share Posted December 10, 2008 Well interestingly enough I just found this old post and it is my mags! I asked Joe to try different springs and followers on my mags not because they weren't reliable, but to get another round or two in the 170's (2). Normally both run fine at .355-.359, 1.240 with Zero 115's, but only 27 rds and likes 26 better in 38 super. Changed back to Arrendondo followers and Wolf +10 13 coil springs, Dawson +1 pads and we are back to 100%. Both 170's work the same now and while I am down on rounds-they work. As an Open Gun student, I am always looking to learn how to keep my guns running myself, but appreciate constructive advice. Thanks for all the great information you all give from this forum. James Link to comment Share on other sites More sharing options...
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