Nemesis Lead Posted September 27, 2016 Share Posted September 27, 2016 (edited) Hi Guys, I am trying to diagnose a gun problem. Here is a link to a public Dropbox picture: I am trying to determine what causes a malfunction like this (the above is simulated with a dummy round). This is a .40 CAL 1911 with rounds loaded to 1.125. The bullets have a rounded profile and a small flat point. I get about 1 malfunction of this type per every 200 rounds and I have no idea what is causing it. The gun is kept clean and lubcricated. I run Wilson Combat 10mm magazines (based on the 47D design I think). When shooting, I usually can slap the back of the slide to get it to go into battery. That works most of the time, but this is obviously a stage wrecker. Do I need a longer / shorter OAL? Do I need a stronger/weaker recoil springs? More stout loads? Different magazines? Something else? How would you go about trouble shooting this? Edited September 27, 2016 by Nemesis Lead Link to comment Share on other sites More sharing options...
scooterj Posted September 27, 2016 Share Posted September 27, 2016 Check for a sharp corner on the bottom of the extractor hook. Link to comment Share on other sites More sharing options...
S&W686 Posted September 27, 2016 Share Posted September 27, 2016 What power factor and spring weight are you running. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted September 27, 2016 Share Posted September 27, 2016 What lube are you using? Link to comment Share on other sites More sharing options...
Nemesis Lead Posted September 27, 2016 Author Share Posted September 27, 2016 Weaponshield lube and a 14 lbs variable recoil spring. Link to comment Share on other sites More sharing options...
Nemesis Lead Posted September 27, 2016 Author Share Posted September 27, 2016 PF is 168. Link to comment Share on other sites More sharing options...
Nemesis Lead Posted September 27, 2016 Author Share Posted September 27, 2016 1 hour ago, scooterj said: Check for a sharp corner on the bottom of the extractor hook. Thank you. I will check for that. What will that sharp corner on the bottom of the extractor hook do? Link to comment Share on other sites More sharing options...
ChuckS Posted September 27, 2016 Share Posted September 27, 2016 Perhaps set a little less extractor tension if the hook is in good shape. There should be a small bevel on the edge of the hook that faces the feeding round. Look for something rough on the breech face. Perhaps add a little more crimp on the ammo. The barrel may need a little more throating. Changing the OAL of the ammo may help. Searching for "3 point jam" may give you more insight. Link to comment Share on other sites More sharing options...
jcc7x7 Posted September 27, 2016 Share Posted September 27, 2016 Seems as though you may be loaded short. Most 1911/2011 feed better in 40 with ammo between 1.180 and 1.200 provided you chamber/throat is that long. Which being an SVI gun a bet it is. Also call Brandon and ask his suggestions on cartridge OAL. IF its running 99% of the time its usually ammo related, OAL , Crimp Etc Link to comment Share on other sites More sharing options...
Nemesis Lead Posted September 27, 2016 Author Share Posted September 27, 2016 Brandon recommended going to 1.2 OAL which locks the slide back prematurely nearly 100% of the time. I think I will try loading to 1.135 and see if that helps. Link to comment Share on other sites More sharing options...
scooterj Posted September 28, 2016 Share Posted September 28, 2016 55 minutes ago, Nemesis Lead said: Thank you. I will check for that. What will that sharp corner on the bottom of the extractor hook do? The sharp edge may dig into the brass and not allow it to slide up the breach face. Link to comment Share on other sites More sharing options...
kamikaze1a Posted September 28, 2016 Share Posted September 28, 2016 If the extractor is okay I would load longer. As for the slide locking back prematurely, relieve the inside of the slide stop lug as it is probably contacting the bullet before the follower.... Link to comment Share on other sites More sharing options...
tmz Posted September 28, 2016 Share Posted September 28, 2016 13 hours ago, jcc7x7 said: Seems as though you may be loaded short. Most 1911/2011 feed better in 40 with ammo between 1.180 and 1.200 provided you chamber/throat is that long. Which being an SVI gun a bet it is. Also call Brandon and ask his suggestions on cartridge OAL. IF its running 99% of the time its usually ammo related, OAL , Crimp Etc Had the same problem until I did this. I found 1.175 turned out to be a perfect length for all my 40 caliber loads. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted September 28, 2016 Share Posted September 28, 2016 17 hours ago, Nemesis Lead said: Brandon recommended going to 1.2 OAL I think I will try loading to 1.135 If Brandon recommends 1.200", I'd go a little longer than 1.135" - I'd try at least 1.180" instead. (Plunk Test first) Link to comment Share on other sites More sharing options...
copecowboy22 Posted September 28, 2016 Share Posted September 28, 2016 Like others have said, load longer. I had this problem with my single stack gun until i had some freebore added to it. Loaded about .010 longer and the problem went away. Link to comment Share on other sites More sharing options...
kcd19 Posted September 28, 2016 Share Posted September 28, 2016 load longer, 1.135 might do it, but i'd try to get it a lot closer to 1.180. 1.200 has been the ticket for me in 10mm magazines. you might be able to go up 1# in recoil spring to "muscle up" on feeding, but that's not really a fix. as was mentioned, if the premature slide lock is coming from bullets contacting the stop, you might be further ahead loading to 1.200 for reliability and re-shaping the slide stop to fix premature lock as a separate issue. you might try a different bullet profile, too -- RN or a RNFP have been much smoother for me at any length, 1.185 - 1.200 Link to comment Share on other sites More sharing options...
CrashDodson Posted September 28, 2016 Share Posted September 28, 2016 Im seeing a similar issue with my SV. I just got the gun back from SV about a month ago. New extractor, hammer, springs, sights, safety. I have about 1.5k rounds on the gun since the rebuild. The slide doesn't go all they way into battery and the extractor is not catching the case. If I drop the mag and pull the slide back and release it will catch and go into battery. I tried removing the extractor to see if it already needed cleaning but I could not get the plate/firing pin stop removed to get the extractor out. I load long 1.21 with 180g blue bullets. I know nothing about tuning the extractor. Link to comment Share on other sites More sharing options...
Bkreutz Posted September 29, 2016 Share Posted September 29, 2016 59 minutes ago, CrashDodson said: Im seeing a similar issue with my SV. I just got the gun back from SV about a month ago. New extractor, hammer, springs, sights, safety. I have about 1.5k rounds on the gun since the rebuild. The slide doesn't go all they way into battery and the extractor is not catching the case. If I drop the mag and pull the slide back and release it will catch and go into battery. I tried removing the extractor to see if it already needed cleaning but I could not get the plate/firing pin stop removed to get the extractor out. I load long 1.21 with 180g blue bullets. I know nothing about tuning the extractor. Here's a link to Brazo's article page, lots of good information (including extractor tuning) http://www.brazoscustom.com/Home.htm Link to comment Share on other sites More sharing options...
TCB Posted September 29, 2016 Share Posted September 29, 2016 I had those same problems with a batch of reloads...not enough crimp. Link to comment Share on other sites More sharing options...
72stick Posted September 29, 2016 Share Posted September 29, 2016 How does it run with factory ball ammo? Are you using range brass to reload or new Starline brass? Your mileage may very, however, until I started using a Redding push through die on my .40 range brass, my SV ran fine with factory ball ammo, but sometimes choked on my reloads. Made it hard to finish a stage without a failure. The failures like the one you have went away on my SV after I started using the push through die and reloading to 1.200 OAL with 180g hollow points. I've tuned all my 1911/2011 competition guns not to lock back on the last round. It's too easy to over insert the mag on a locked back slide and damage the ejector when your on the clock. Link to comment Share on other sites More sharing options...
RangerTrace Posted September 29, 2016 Share Posted September 29, 2016 On September 27, 2016 at 4:19 PM, Nemesis Lead said: Hi Guys, I am trying to diagnose a gun problem. Here is a link to a public Dropbox picture: I am trying to determine what causes a malfunction like this (the above is simulated with a dummy round). This is a .40 CAL 1911 with rounds loaded to 1.125. The bullets have a rounded profile and a small flat point. I get about 1 malfunction of this type per every 200 rounds and I have no idea what is causing it. The gun is kept clean and lubcricated. I run Wilson Combat 10mm magazines (based on the 47D design I think). When shooting, I usually can slap the back of the slide to get it to go into battery. That works most of the time, but this is obviously a stage wrecker. Do I need a longer / shorter OAL? Do I need a stronger/weaker recoil springs? More stout loads? Different magazines? Something else? How would you go about trouble shooting this? No question about it, load as close to 1.20" as you can. If you're worried about the extractor. Pull the slide off and slide one of your rounds up the breechface behind the extractor and give it a little shake. If it stays in place. You have enough tension. I doubt you have too much tension, but if you have a really hard time getting the rim behind the extractor, you could have too much. I've never had long rounds cause the slide to lock back prematurely. You could always increase the depth of the relieved area in the slide stop the detent rides in. Push feeds are fairly common with short rounds. The shorter rounds give the round a little wiggle room before the round is fully captured between the extractor and feed ramp. And, if it continues to give you a problem, send it back to the factory with your ammo. Link to comment Share on other sites More sharing options...
pjb45 Posted September 29, 2016 Share Posted September 29, 2016 You have other solutions for lock back. Adjust the followers on the front left side or detent in the slide stop. My one SV with a Nowlin barrel likes long loaded --1.175+. My SS will shoot factory ammo. Are you using a Lee/EGW FCD? Link to comment Share on other sites More sharing options...
resortboarder Posted October 3, 2016 Share Posted October 3, 2016 I had the same/similar FTF after I got my Para Pro Custom .40 back from my gunsmith. I got to my next match and 1-of-5 or so would do this. I could always bump the back of the slide and it would go into battery. He had tightened the extractor on his own whim (not requested) because he said it was loose. I bent the extractor back out just a little and I've never had the problem since. I load 180gr RNFP @ 1.180" over 4.7gr of Titegroup at 168 PF. 12LB Wolff recoil spring. Link to comment Share on other sites More sharing options...
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