openglock34 Posted February 22, 2005 Share Posted February 22, 2005 just took my new open gun to its first ipsc match, gun is glock 34 with kkm barrel 4 hybrid ports and 3 port comp (pictures in gallery) the rounds i was using were 115 gr bullets 8.1 grains of hs6 and a oal of 1.14, i had a 11lb wolff spring and a non captured tungsten guide rod with 17rd mags and arredondo +6 ext. the problem i had was that out of every mag about two of the rounds would jam. it was a match so i didnt have time to fully concentrate on what exactly was happening but what it looked like was the round was feeding half way into the chamber and getting stuck and the instant i would drop the magazine the slide would go into battery and chamber the round just fine. i know its not a huge deal because the gun is brand new with less then 300 rounds through it (which could be part of the problem) i was going to play with loads ideally using a 125 gr montana gold bullet for more pressure and reach major more easily (i got the 115grains for free and they worked so i used them) and i am going to play with spring rates i think. but i just figured one of you may have heard of this problem before and can get me started in the right direction and maybe save me some troubleshooting hassle and time. it did this most importantly in the middle of a classfier causing me to lose some serious time "OUCH" . I love the gun and it has been working great just need to get this minor gliche out of the system. thanks, shawn Link to comment Share on other sites More sharing options...
benny hill Posted February 22, 2005 Share Posted February 22, 2005 did you throat & polish the feed ramp & chamber? also try ISMI glock mag springs, they really help the feeding. Link to comment Share on other sites More sharing options...
eric nielsen Posted February 22, 2005 Share Posted February 22, 2005 Just a guess, rounds are too long - especially if you're using hollowpoints. As far as gun and spring - you're in prototype land already. Don't worry, I'm one of BrianH's next test pilots. My best luck with Major rounds in a short gun [9x21 and the old 175pwr factor] was 1.125" OAL with 124gr jacketed round nose. Use calipers on EVERY match round until you sort out what you WANTED to load and what you DID load - these can be 2 different things if your load is compressing the powder. Hollowpoints should go a little shorter, but probably almost the same seating die position as what roundnose at 1.125 uses. Go practice. When the malfunction happens, look & see if the bullet is trapped against the feedramp and the casehead trapped against the mag feedlips. That means too long. Try every mag you have. Probably don't want to go longer than 1.135. As Benny says a polished feedramp is a big help. Good luck. Link to comment Share on other sites More sharing options...
TDean Posted February 23, 2005 Share Posted February 23, 2005 If it's your bullets, they will malfunction with a stock (non-ported) barrel too yes? I'm inclined to think it's a timing issue. 4 hybrid ports and 3 comp ports might be bleeding off too much energy to effectively run the slide. Without changing anything else, shoot it without the comp. What happens? Link to comment Share on other sites More sharing options...
openglock34 Posted February 23, 2005 Author Share Posted February 23, 2005 what is throat the feedramp and chamber? i did polish the feedramp but i am not sure about throat, i know i still need some breakin time and im sure that will help it, but as one of you said OAL could also be the problem, im loading to 1.14 and when the bullet got chambered it went in half way, i didnt check the case lip but as soon as i dropped the mag it chambered imediately which leads me to believe that it was hanging up on the feedlip on the mag. so maybe i will try 1.125 or 1.13 or something along those lines, the reason i loaded 1.15 was just because that is what was suggested to me from a fellow open glock shooter. if that is the case where the oal length is too long just shortening it down to 1.125 should potentially solve the problem i guess????? also..how can i use an ismi mag spring because they are only for the high cap magazine that i do have. but shouldnt the mag spring be longer considering im using the 17 rd mag and arredondo +6, would it still work? Link to comment Share on other sites More sharing options...
benny hill Posted February 23, 2005 Share Posted February 23, 2005 Call mark at ismi, he makes mag springs for ext. mags for glock. Link to comment Share on other sites More sharing options...
bberkley Posted February 23, 2005 Share Posted February 23, 2005 Try a heavier recoil spring. Factory Glock recoil springs are 17# for most of their models. I would get a 13#, 15#, and 17# IMSI springs. I would also get the Wolff extra power magazine springs and try those. Another alternative would be to take a factory recoil spring assembly, chuck it into a drill, and hourglass it with a file, making a progressive spring like Dale Rhea does. I always had issues in my G35 with a drop-in KKM barrel and the Westcoast Plated 180gr RNFPs at any OAL between 1.125 and 1.135. Switched bullets to Montana Golds, or Lasercast, or Bear Creek Moly's at any OAL between 1.125 and 1.135 with ZERO problems. So the problem could be your bullet/OAL. One last thing to check if you have a LCI extractor is that the spring-loaded bearing for the LCI extractor models is different, and if you have the wrong one, that can cause misfeeds. Link to comment Share on other sites More sharing options...
George Posted February 24, 2005 Share Posted February 24, 2005 Had a similar problem until I took my Open 17L back up to a 13 pound spring. The slide always closes now. The OAL in a Glock is limited by mag length and something in the 1.135” to 1.165” range has to be fine because there is no other option with this platform ;-) I tried an 11 pound spring to retard the slide a little and allow the rounds time to rise in the mag, but found the lack of oomph closing the slide was a bigger problem. I solved the bullet rise rate problem with mag spring and follower replacements from Beven Gramm at http://www.grammsengineering.com/ A 13 pound spring is fine if you get the rounds up from the mag fast enough and I think it will solve this problem. It probably is more of a timing thing than an ammo thing unless your rounds are bulged, or you have headspace issues in the chamber. JMHO anyway. Check that the primers are all flush, or recessed at the case head. If any are sticking up that could be the culprit too. -- Regards, Link to comment Share on other sites More sharing options...
joelaw99 Posted February 28, 2005 Share Posted February 28, 2005 i use an imsi 15# in mine, 24 with 6 ports in the barrel and three port comp with four side bleeders...... Link to comment Share on other sites More sharing options...
joelaw99 Posted March 13, 2005 Share Posted March 13, 2005 i just built a new open top in 9major,,,its a 17c slide with six ports in the barrel blowing thru the stock c slide porting and my own three chamber comp. w/ four side bleeders, imsi 13#, and it keeps more pressure on the slide uncaptured instead of captured......really flat with factory stuff. i cant wait to get some 124's loaded up around 1350fps,,,,,should be dead flat with em.. http://www.hunt101.com/img/263906.JPG Link to comment Share on other sites More sharing options...
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