Singlestack Posted June 7, 2003 Share Posted June 7, 2003 Ok folks, bear with me cuz I think I'm going to have a hard time explaining this. My shooting Pard has a Gunsmith kit .40 cal, long dust cover STI that he built the bottom on and he has been shooting it for about a year. I think the firing pin stop slot is cut too far in. He has tried several different make extractors including STI and currently, Aftec. All sit recessed from the back slide by about .010 and all do not hold the brass to the breechface. There is about a .020 gap between the brass and the breechface. This has caused, IMO, several problems. 1) intermittant light primer hits. 2) intermittant extraction problems. 3) intermitant feed problems 4) and to top it off, a ejector fire. He had a light primer hit and when he racked the round clear, it slipped out from under the extractor and right into the ejector. Pretty scary but he was, luckily, not hurt. He is an amature GS and failed to notice the gap between the brass and the breechface when he installed the first extractor. The ejector fire freaked us out plenty (cost him a match DQ at Area 6) so we tried to understand how this could happen and prevent it from happening again. He purchased the Aftec and discovered the gap while fitting it. He asked me how to move the extractor back, and I don't think you can do that. The only thing that makes sense to me is the firing pin stop slot is cut wrong. Am I totally in the weeds here? Link to comment Share on other sites More sharing options...
L9X25 Posted June 8, 2003 Share Posted June 8, 2003 SS, The dimension from the breechface to the rear of the slide (where the FP stop plate goes) should be about 2.170 +/- .005. This dimension does vary from slide to slide, even within the same manufacturer and, therefore, your extractor will accordingly seem short or long for that particular slide. I have had the exact opposite problem on some of my guns in that the extractors were too short and did not allow the guns to feed with proper extractor tension. Thankfully extractor length also varies from part to part and I can usually search my parts bin for a longer/shorter extractor to match that particular slide or re-cut the hook to lenthen the extractor that I am using. It sounds as if you will need to find a short extractor, if that is indeed your problem, since you cannot easily make your slide longer or your current extractor shorter. I would try checking your current extractor tension with a gauge to make sure that the extractor is not bottoming out against the slide. If this is happening you can add all the tension you want and none of it will increase the grip on the case. All of the problems that you list can be caused by a bad extractor fit except for the light primer hits. The case should headspace in the barrel and the extractor should not influence this. If you were shooting .40s out of a 10mm barrel that would be important, but not on a properly fitted/chambered .40 barrel. You will need to look at the usual suspects for the light primer hit problems. Good luck, Leo Link to comment Share on other sites More sharing options...
Singlestack Posted June 8, 2003 Author Share Posted June 8, 2003 The extractor tension is good. How in the heck am I to find a extractor that is .020 shorter than normal from the hook to the firing pin stop slot? We have tried a Ed Brown, STI, and Aftec. All are too long and do not hold the round to the BF. "All of the problems that you list can be caused by a bad extractor fit except for the light primer hits." Even if the round is not held to the BF? I will measure the slide today for 2.170. I'm willing to bet right now that it is 2.150 or less...... Link to comment Share on other sites More sharing options...
JasonK Posted June 9, 2003 Share Posted June 9, 2003 Even if the round is not held to the BF? Yes, because the case should be held against the breechface by the case mouth. I'm assuming the headspacing is within tolerance on that pistol. Link to comment Share on other sites More sharing options...
L9X25 Posted June 9, 2003 Share Posted June 9, 2003 SS, As Jason stated, you could literally remove the extractor from the gun and the cartridge would or should headspace on the shoulder in the chamber and fire correctly. It would not extract but it would fire. If you chamber a round and remove the magazine, will the extractor hold the round tightly in place, while you slowly hand cycle the round, until it reaches the ejector? (I recommend checking with a dummy round if you have one handy). If the round falls or droops drastically you may need to clearance the mounting pad. Did you check the extractor tension with a gauge? If so, how many OZs is the extractor set at? If your slide is considerably undersized, I do not know what you will be able to do to resolve the problem beyond searching for an undersized extractor to match it. You might contact a gunsmith or parts supplier that is willing to measure his stock for a particularly short one. I prefer to have some extra clearance between the headstamp and the boltface to allow adequate extractor tension and reliable feeding. If you have a zero clearance situation you WILL have occasional feed problems with different brands of brass or brass that has been beaten up some. I checked (3) .40 cal extractors that were in my shooting bag and they measured 2.335 (Caspian), 2.342(Aftec) & 2.365(series 80 Ed Brown?) from the hook to the rear of the FP stop plate groove. On my guns, I prefer extractors that are 2.340 and longer for reliable function. Good Luck, Leo Link to comment Share on other sites More sharing options...
Mad Scientist Posted June 9, 2003 Share Posted June 9, 2003 John, If I remember 1911's ther shoulb be some clearance betwen the extractor case and breachface. .020 sounds like a lot but rember the case has to cam up into the barrel past the exstracter.if it were to tight the case would bindup and the gun would not go into batery. The afterc in the viper I once owned had much case clearance. I would suspect that the tension is off I have heard of slides not cut deep enough where the exstracter meets the slide . and not enough lateral movment alowed there of. The case should be heald tightly against the oposit side of the slide away from the exstracter. and clearance is usual a good thing. I am not an exspert at 1911 so I will refere to joey or rusty. On the light strikes I am very versed as you know. what I have found is with a lose chamber the round flops around and light strikes are prevelent. you should have a max of .008 clearance from cart. to breach withevery thing in battery. take the slide off and messure with a feeler gauge. Maybe some short cases got in? John Nagel Link to comment Share on other sites More sharing options...
2alpha Posted June 9, 2003 Share Posted June 9, 2003 The extractor is not supposed to hold the case against the breach face, if it did it wouldn't feed. You have to have some clearance for the round to make the corner into the chamber, the case rim starts at an angle to the breach face until the round gets in the chamber. The most likely cause of light firing pin hits is high primers, the firing pin has to seat the primer instead of denting it. If not that you could have a broken firing pin spring binding up the firing pin or debris in the firing pin hole. Titanium firing pins are notorious for causing light hits. If the slide doesn't go completely into battery you can get a light hit. Are you shooting lead bullets? There's more but that's all I can think of right now. Link to comment Share on other sites More sharing options...
Singlestack Posted June 11, 2003 Author Share Posted June 11, 2003 The main problem is the ejector fire. The slide might be ok, I was just trying to figure out the ejector fire. The extractor has good tension holding the round against the opposite side of the BF. When I was looking at the tension with the slide removed, I noticed the .020 gap between the BF and the round. My friend then showed me the recessed rear of the extractor in the slide and told me that every one he had tried was like that. Every gun that I have looked at very closely (and thats not a whole lot) for extractor tension, held the round to the breachface a lot closer than .020. 2Alpha, No lead, no titianium, no broken spring. The light hit that caused the ejector fire was due to a cut shok buff that had been inserted between the MS housing and the grip safety to pin it and it worked its way foward and was rubbing the strut. I was being stupid and forgot that the case would be headspaced in the chamber. I am grabbing at straws trying to understand the ejector fire and to prevent its reoccurance. I know that its a scary, dangerous thing that I don't ever want to see again! I've been out of town the last 2 days and have not talked to my buddy. I will call him tonight and ask him about the measurements. Link to comment Share on other sites More sharing options...
benny hill Posted June 12, 2003 Share Posted June 12, 2003 I have seen lot's of ejector fires. They are caused by someone racking the slide back fast to eject a rd. The simple sulotion that I use is to pull the slide back slowley & let the rd. dribble out. Problem fixed. Link to comment Share on other sites More sharing options...
Mad Scientist Posted June 14, 2003 Share Posted June 14, 2003 John, Ya know benny might be on to something. I remember a mutual friend that racks the slideand catches the round up in the air. Is this your friend ? P.M. with answer if ya like. Johnnie Link to comment Share on other sites More sharing options...
Mad Scientist Posted June 14, 2003 Share Posted June 14, 2003 John , Didnt catch your last post . I didnt realize he had a problem during the stage and was clearing. sounds like the heat was on and that slide was coming back fast.so benny may have hit it anyway. I always cringe as an R.O. when i see the rounds caught in the air I always tell my self theres an A.D. waiting to happen. I always thought that after the stage was over you wasent in no hurry. Hope he gets it together for cherokee. see ya there. Link to comment Share on other sites More sharing options...
diehli Posted June 14, 2003 Share Posted June 14, 2003 Reason I launch the round into the air and catch it is 'cause I ain't keen on the bending over... being fat and lazy and all. I have to get psyched up to pick up brass. Link to comment Share on other sites More sharing options...
rkgsmith Posted June 16, 2003 Share Posted June 16, 2003 I have personally seen 4 rounds go off due to the ejector hitting the primer. A lot has to due with long ejectors and short cases. I have also seen rounds detonate by dropping them on a hard surface like black top. It is also possible to have a delayed detonation so ejecting the case and catching it is also asking for trouble. Do yourself a favor and rack the slide slowly with the ejection port pointed away from your face and the RO. If you handle fireams long enough you will have and AD, but where that round goes is all dependent on the person with the gun. Link to comment Share on other sites More sharing options...
Flexmoney Posted June 16, 2003 Share Posted June 16, 2003 I never worry about picking up the round that I send to the ground when I "show clear". What's that...one round per stage? Four to Six at a local match... not worth the hassle. Link to comment Share on other sites More sharing options...
diehli Posted June 16, 2003 Share Posted June 16, 2003 Ah yes... forgot to add cheap. Picking up my first STI at the end of this week, so I'll probably try to ditch that Glock practice, just in case. Also, apparently, it's a bad habit... lord knows I've got enough of those and don't need another. Link to comment Share on other sites More sharing options...
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