blackrazor

Hi all, After spending lots of time looking very carefully at my extractor problem with my STI, I've also noticed what may be a machining flaw in the breech face of the slide (mine is a .40). Esentially, the breech face is not a perfectly flat plane, there is a raised ridge running along the right side, right above the location of the ejector cutout. It looks almost like the breechface was finished by two separate machining operations, and they weren't done at exactly the same "depth". The result is the brass doesn't fit perfectly square against the breech face, and after firing, every piece of brass has this step indentation on it. Has anyone else seen this before, is this a real problem or am I just obsessing about things that don't matter? If I did want to get it fixed, could STI take care of it, or could I send it to a gunsmith to polish out the raised section of the breech face? Finally, is the fact that the slide is hard chromed going to require me to refinish the slide if I get this fixed? Thanks for any help.

Huh, well that would explain quite a bit. I've give Derek a call on Monday and hopefully I'll have this whole thing fixed up in no time. Thanks!

I fully intend to remove the shock buff on my next trip, I just don't understand how it has any affect on extraction. Of course, if it works, it works, I won't question any working solution, although I would still like to know what exactly is causing my problem, even after I've fixed it. As far as getting a "normal" extractor, I suppose I could go that route, although it seems strange to need to do so, especially since the Aftec is supposed to be far and away the best on the market. BTW, I am sure that I'm running a .40 cal extractor, that much I am sure of!

Wow, this forum is great, I've never seen so many good responses. I just wanted to let everyone know that I'm very appreciative of all the help. I took the pistol to the range again today in an attempt to help nail down the problem. First off, to respond to someone's earlier question, my brass is ejecting about 3 feet to the right, and about 1 foot back from the pistol. I threw the older Aftec back into my gun, and it is much better than the newer one; it went for about 120 rounds before I had the inevitable failure to extract. It was the same failure I always get: there was a fired/empty case in the chamber, and the gun stopped when trying to feed the next round (which crashed into the back/bottom of the empty brass). I don't think that this jam could possibly be the result of using something like a shock-buff, since the slide obviously traveled far enough back to pick up the next round. I've attached some close ups of the brass that failed to eject, trying to show the marks left on the rim by the extractor. It seems pretty clear to me that the extractor "jumped" over the rim, but maybe somebody else here might have another opinion? As far as the chamber itself, I had my gunsmith check it out and there aren't any burrs, roughness, or other marks that could be trapping the brass in the chamber. I'll try to mark the extractor and check to make sure it's not hitting the barrel; that's an interesting idea I hadn't thought of. But in the mean time, I think the most likely culprit is the extractor hook itself. Especially when you look at the marks left on the case, and that the problem changes dramatically by just swapping out the extractor with another (nearly) identical unit. Although both of my Aftecs seem to skip over rounds and fail to extract, one of them does it once every 100 rounds, while the other does it about once every 20 rounds. I would think that you would want your extractor to grab as much of the case as possible with the most square, sharp hook as possible; theoretically I would think that if your brass was too tight in the chamber, you would get the extractor to tear the rim or shear off part of the rim long before it would ever "skip over". ***edited to add*** I just checked the extractor/barrel issue and the extractor is definately *not* hitting the barrel at any time during the cycling of the gun, I can actually see the brass between the gap between the extrator and the barrel at all times when cycling by hand, and I marked it up with a black marker and no ink came of the front of the extactor after cycling several rounds.

I can't put all the stock parts in, I don't have them anymore (including the original extractor). So I don't know if STI will work on it now... it may be best just to go with a top notch gunsmith and pay whatever I have to pay to ensure that this gun will come back with 100% reliability. The only ammo I've ever shot through this gun is Winchester white box (Wallyworld) ammo, which should be fine (lots of people I know have shot 1000's of rounds of this stuff without a single failure). In other words, even if switching ammo "fixes" the problem, any gun that can't cycle FMJ winchester white box has a problem. I've looked at the cases left in the chamber, I've noticed the extractor claw marks on the inside edge of the rim, I don't recall seeing anything on the outside of the rim. However, since the brass is being left in the chamber, and the extractor was obviously pulling on the case at some point in time, I think it must have slipped over at some time. Every time the jam occurs, there is an empty casing in the chamber, and the gun is trying to feed a new round into it from behind. Yes, but as far as I can tell a shock buff could only screw up ejection, not extraction, right? I can't tell where the brass is landing since I've done the testing at an indoor range and the stall divider is right next to me.

Yep, I just took that picture, it's my aftec extractor holding a loaded round in place, as viewed from the bottom of the slide. The lack of a sharp 90 degree angle is what I was trying to show, I don't think it's going to help extraction having that rounded profile behind the extractor hook. As the extractor moves backward under recoil, it seems to me that the case rim could push/roll the extractorout of the way, rather than grabbing the rim with authority. Also, as you can see from the picture, it seems that there is a fairly large gap between the tip of the hook and the groove in the brass case (right ahead of the rim). If the hook were longer, perhaps it would increase the area of contact with the case, this would help, right? I'm thinking about trying to grind the extractor to increase the length of the hook, and sharpen up the hook angle to a more 90 degree profile. My guess is, that the extractor should look something like this: But I don't want to mess with it until I'm sure I know what I'm doing, and for now I'm sure I *don't* know what I'm doing FWIW, both of my Aftec extractors look just like this, which puzzles me since I'm guessing that means they're supposed to be made this way, but I don't see how non-90 degree angles and shorter than possible extractor hooks could do anything to help reliability.

It sure does, the extractor pushes fairly hard on the case, but as you can see from the pictues, the pressure is all on the part of the extractor behind the hook where it contacts the base of the rim. I did test and make sure that the extractor holds the fired and unfired brass, and it does. If you look at the picture I've attached to this message, the extractor will hold that round in place even if I shake the slide quite a bit. The gun is a standard STI tactical (built by STI), and I've added the Aftec extractor, an aftermarket guide rod and wolff recoil spring (I didn't like the STI recoil master). I've also added an extended slide stop and stippled grip, but I don't think those could have any effect on extraction. Is there any way to diagnose a "barrel timing" problem? What causes this?

OK, So I've been screwing with this all day. I checked the extractor fit without the springs installed, and when I've thrown in the firing pin stop the extractor can move from left to right freely, so I'm guessing this isn't a problem with radiusing the firing pin stop. I also took my pistol into King's gunworks, where they told me the problem is happening because I am using too heavy a recoil spring, because my gun must be short stroking and rechambering the empty brass. I asked them, if that's the case, why haven't I ever pulled the trigger on a fired piece of brass, and how come by slide always locks back on the last round? Then they told me that the problem is the extractor itself, and that the only extractors that work are Colt extractors. Looks like I've wasted more of my time going there, since everyone I've ever met says the Aftec's are the best extractors on the market. Anyway, I'm pretty much at a loss here, I'm sure I could try fixing this for a month and never get anywhere. The only thing I can see is that the extractor hook looks a little too short to me, i.e. it doesn't grab as much of the case rim as it could if it were longer. Also, the hook is slightly radiused, so that if you look really closely, the brass case edge is the only part of the case in contact with the extrator. I've tried to attach a picture which shows what I'm talking about, but I don't know if it's of any help.

Thanks for the replies guys. To answer your questions: 1) Yes, I've tried 3 sets of Aftec springs, I've even tried two different Aftec extractors, same problem every time. 2) I'm not sure, but I suppose it's possible that both of my Aftec's have defective hooks; one of them is about a year old, the other one I bought a couple of days ago. 3) I don't think the firing pin stop is beveled so this may be my problem. Does anyone know of a good gunsmith I can send my pistol to so that I can get this thing fixed right once and for all? Thanks again for the help!

Hey all, I've been having a problem with my .40 cal STI tactical 5.0 not extracting rounds. I'd say 1 out of 20 on average failures; what happens is the spent brass is just left in the chamber and the new round jams into it from behind. I have the Aftec extractor, and I tried fitting an additional extractor but that didn't solve the problem. I've also increased the tension on the extractor by using an oversized firing pin stop, still no fix. This problem's starting to drive me nuts, but I figured someone on this forum may have some additional tips/advice. If anyone has any suggestions they would be greatly appreciated! Thanks for any help