kmc Posted December 14, 2014 Share Posted December 14, 2014 I have a new STI Sentry in 40 and it nosedives nearly every time from slide lock had drives the round directly into the base of the feed ramp. I'm using new Tripp Cobra 40 mags. This happens with factory (Federal 180gr) and my limited ammo (180 gr, 1.19 oal) though my limited ammo is a tight fit in the 40 mag. It happens with Tripp and DW 40 mags. I've tried multiple mags with the same results The included STI mag (can't take down?, no base pad) works only some of the time with factory ammo 45 mags seem to work 100% but won't always drop free if there are rounds in mag I've polished the feed ramp to look like a mirror I'd like to try a 10mm mag but don't have one (yet) I tried polishing the feed lips I've checked carefully to make sure slidestop isn't interfering I've read various posts about Trojans with similar sounding issues. Has this problem been present on Sentry's too? This is very frustrating for a brand new gun! Any ideas on where I go next? Attached photos are of nosedive and view of mag after nosedive Link to comment Share on other sites More sharing options...
JMike Posted December 14, 2014 Share Posted December 14, 2014 IMHO, I would contact STI to send the pistol back for a factory fix. Link to comment Share on other sites More sharing options...
jcc7x7 Posted December 14, 2014 Share Posted December 14, 2014 Does this happen with the mag full? If there are a couple of rounds taken out of the mag does it feed? I recently bought 8 new mags for my 40 and had to let them sit loads for a couple of days before they would feed. New out of the box those mags would feed fine with one or two rounds but not loaded to the top. The gun had previously feed with my older mags (with the softer or set springs in the mags) Might be worth a try jcc7x7 Link to comment Share on other sites More sharing options...
kmc Posted December 14, 2014 Author Share Posted December 14, 2014 Does this happen with the mag full? If there are a couple of rounds taken out of the mag does it feed? I recently bought 8 new mags for my 40 and had to let them sit loads for a couple of days before they would feed. New out of the box those mags would feed fine with one or two rounds but not loaded to the top. The gun had previously feed with my older mags (with the softer or set springs in the mags) Might be worth a try jcc7x7 Link to comment Share on other sites More sharing options...
kmc Posted December 14, 2014 Author Share Posted December 14, 2014 It happens with 7-9 rounds in the mag. If I back off to 5fewer than -6 the problem goes away. I can load up the mags and let them sit for a few days while I call STI Link to comment Share on other sites More sharing options...
2MoreChains Posted December 14, 2014 Share Posted December 14, 2014 Sounds like the feed ramp angle is a tad too steep. Link to comment Share on other sites More sharing options...
shotgunone Posted December 14, 2014 Share Posted December 14, 2014 Check your extractor. It may not be allowing the case to be pulled back against the breach face. Could be a little bit loose. Or could be more than one issue going on too. Link to comment Share on other sites More sharing options...
kmc Posted December 14, 2014 Author Share Posted December 14, 2014 I'm not sure how the extractor would be in play yet. This is from slide lock with magazine full and the chamber empty. Upon releasing the slide lock, the top round is driven directly into the very bottom of the feed ramp and the whole slide comes to an immediate halt...usually driving the bullet to a deeper seating depth. I don't think the extractor is involved at this point, is it? Link to comment Share on other sites More sharing options...
shotgunone Posted December 14, 2014 Share Posted December 14, 2014 (edited) I couldn't really tell by the picture if it is started under the extractor or not. If it's not making it that far then your right that wouldn't be part of the problem. Another thing to try is pushing up firmly on the bottom of the magazine while releasing the slide to see if that makes a difference. If the magazines are setting too low in the frame it might contribute to the problem too. You can always get on STI site and send in a warranty report on the gun. They are suppose to have a great warranty on their firearms and good about taking care of their customers. Edited December 14, 2014 by shotgunone Link to comment Share on other sites More sharing options...
kmc Posted December 14, 2014 Author Share Posted December 14, 2014 I couldn't really tell by the picture if it is started under the extractor or not. If it's not making it that far then your right that wouldn't be part of the problem. Another thing to try is pushing up firmly on the bottom of the magazine while releasing the slide to see if that makes a difference. If the magazines are setting too low in the frame it might contribute to the problem too. You can always get on STI site and send in a warranty report on the gun. They are suppose to have a great warranty on their firearms and good about taking care of their customers. I did try using my bench to hold the magazine firmly up while I dropped the slide. It did not seem to make a difference, though maybe even more *firm* pressure would have helped. Link to comment Share on other sites More sharing options...
kmc Posted December 15, 2014 Author Share Posted December 15, 2014 I went out and did some further testing tonight based on the questions above. I used two different magazines and stuck with only factory ammo (Federal 180gr FMJ) this time. The two magazines were a new Tripp Cobra 40S&W (capacity 9) and the STI factory mag with no basepad (capacity 8). All testing was from a the mag loaded with all rounds fully seated, the gun at slide lock, and just dropping the slide lock. I found the Tripp mag would chamber the top round just fine up to and including 7 rounds (5 for 5 anyway), but failed at 8 or 9 rounds nearly 100% of the time. The STI mag worked fully loaded (8 rounds) about 4 out of 10 times (first 3 in a row worked). At the point of failure, the round is still mostly in the magazine and below the extractor--it hasn't rotated up and moved up far enough for the extractor to engage. I also tried to *firmly* hold the magazine up to see if that changed the results. Although I did get it to work one time with Tripp mags loaded @ 8, in general it seemed to make no difference. As a result, I've started the process of engaging STI on a warranty repair by submitting a pistol report--we'll see what transpires next. Link to comment Share on other sites More sharing options...
Marv Z Posted December 15, 2014 Share Posted December 15, 2014 I had the same problem with my .40 Trojan. After shooting SS for an entire year with Wilson 45 mags with no problems, I bought 6 Tripp 10mm mags as I load long (1.185). Nosediving started immediately and after contacting Aaron at Tripp, he recommended an EGW raised mag catch. I did install it and it has made the problem better, but it will still do it about 5-10% of the time. The problem according to Tripp is the angle of the feed ramp. It's too steep and normal variations in the mags and pistol frames cause some pistols to have this issue. Easiest fix is 45ACP mags and load as long as possible. They offered to weld and re machine the feed ramp for a nominal cost to permanently cure the issue, but I elected not to have this done yet. If I go back to SS again, I will let Tripp rework the pistol. If STI can't fix it, call Aaron at Tripp. Link to comment Share on other sites More sharing options...
kmc Posted December 15, 2014 Author Share Posted December 15, 2014 Thank you...that matches my suspicions. I usually shoot 45 SS so tried some well-used 45acp mags (just a couple of mags worth) and they worked 100% but they don't seem to always drop free. It looked to me like the top round had made its way far enough up in the feed lips to cause some spreading/binding. Link to comment Share on other sites More sharing options...
robertg5322 Posted December 15, 2014 Share Posted December 15, 2014 Ditto the EGW higher mag catch. Also, I had the same issue with a Franken1911, converted Kimber to .40. When I switched to the EGW mag catch and moved to round nose flat point vs. truncated cone bullets(180g), the issue went away. Not sure if the mag catch or the bullet profile was responsible, I switched the mag catch and bullets at the same time. It will not feed anything I give it. Mags are a mix of Tripp 9 rounders and Mec Gar, Check Mate and Metalform 8 rounders. All feed perfectly. Of note, to get the gun running, I had to polish and adjust the extractor, and use the EGW mag catch. Springs are 12.5 lb recoil spring and 17lb mainspring. The gun has an aluminum shock buff from Dawson Precision. Link to comment Share on other sites More sharing options...
OscarMike Posted December 15, 2014 Share Posted December 15, 2014 I had 0 problems feeding with my sti sentry out of WC mags. I did have a trigger problem, and sti has the best customer service I've dealt with so far Link to comment Share on other sites More sharing options...
kmc Posted January 2, 2015 Author Share Posted January 2, 2015 (edited) I wanted to provide an update to my thread. I submitted a problem report to STI, including the descriptions given earlier in this thread. They asked me to send the barrel in and they returned it within about 10 days (over Christmas) and had re-cut and polished the feedramp. The feedramp now starts at the very bottom of the metal a notideable change from the original (see pics attached). I've not run much through it but in 2 mags of factory 40 from Tripp 40 mags and 2 mags of my limited (longer) ammo run from Tripp 10mm mags, I saw absolutely no feeding issues at all. I think this problem is now behind me. I'd be curious to know if I had an "out of spec" feed ramp originally or if they all look as in the "before" picture. Apparently my attachment didn't work--will try again. Edited January 2, 2015 by kmc Link to comment Share on other sites More sharing options...
bountyhunter Posted January 2, 2015 Share Posted January 2, 2015 (edited) It happens with 7-9 rounds in the mag. If I back off to 5fewer than -6 the problem goes away. I can load up the mags and let them sit for a few days while I call STI My new Para 1640 did that. Only way to fix it was to recut the feed ramp. The good news is you are dealing with an excellent company (STI) not a schlock house like Para. I don't think your feed ramp was "out of spec", I think it just had to be fitted a bit to match the frame height. Edited January 2, 2015 by bountyhunter Link to comment Share on other sites More sharing options...
bountyhunter Posted January 2, 2015 Share Posted January 2, 2015 (edited) I had the same problem with my .40 Trojan. After shooting SS for an entire year with Wilson 45 mags with no problems, I bought 6 Tripp 10mm mags as I load long (1.185). Nosediving started immediately and after contacting Aaron at Tripp, he recommended an EGW raised mag catch. I did install it and it has made the problem better, but it will still do it about 5-10% of the time. The problem according to Tripp is the angle of the feed ramp. It's too steep and normal variations in the mags and pistol frames cause some pistols to have this issue. I have noticed the same thing. I wondered if the barrel makers made the ramp steeper to get "full coverage" on the .40 case after the Glock .40's blew out some cases and everybody started freaking out. The .40 is a high pressure case and some old cases that have been reloaded too many times can rupture if not fully supported. I can't think of any other good reason to make the feed ramps look like a cliff face.... anyway a "raised mag catch" will raise the mag but the corner of my Mec gar mags were bumping into the ejector and I had to file it for clearance. Edited January 2, 2015 by bountyhunter Link to comment Share on other sites More sharing options...
cbrconst Posted January 2, 2015 Share Posted January 2, 2015 Ditto the EGW higher mag catch. Also, I had the same issue with a Franken1911, converted Kimber to .40. When I switched to the EGW mag catch and moved to round nose flat point vs. truncated cone bullets(180g), the issue went away. Not sure if the mag catch or the bullet profile was responsible, I switched the mag catch and bullets at the same time. It will not feed anything I give it. Mags are a mix of Tripp 9 rounders and Mec Gar, Check Mate and Metalform 8 rounders. All feed perfectly. Of note, to get the gun running, I had to polish and adjust the extractor, and use the EGW mag catch. Springs are 12.5 lb recoil spring and 17lb mainspring. The gun has an aluminum shock buff from Dawson Precision. ^^^Same problem same solution. High hold mag catch from EGW. At the time they did not have a tapped version, but not terribly difficult to do. Link to comment Share on other sites More sharing options...
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