matteekay Posted January 29, 2018 Share Posted January 29, 2018 Howdy! I've had a few failures to feed in my RIA TAC .45 ACP full-rail 1911 in the last few USPSA matches using Tripp 10 round magazines. I've been doing some reading at RangeHot and I'm apparently seeing the "bolt over base" malfunction, where the round is jammed under the barrel hood and prevents the gun from going into battery. I've been able to clear it with a quick racking every time. They cite weak mag springs as the common cause of these failures and also mention over-springing the gun. I'm a little hesitant to blame the mag springs - the gun has seen less than a thousand rounds in total, spread out over six magazines. However, the recoil spring comment got me thinking. I'm running handloads that make about a 169.5 PF and RIA installs a 18# recoil spring from the factory. Is it possible that the slide is out-running the magazine because I have too much recoil spring tension? It's not happening very frequently (once or twice a match) but that's still more than I care to see (again, once or twice a match, lol). I'm still pretty new to the world of 1911's so any help is appreciated. Link to comment Share on other sites More sharing options...
IsaacB Posted January 29, 2018 Share Posted January 29, 2018 To me this sounds like a back-to-basics diagnostic thread. In general, if the recoil spring is within normal specs the gun should run. If the difference between a 16 and 18lb recoil spring is the difference between function and jamming, then you're right on the edge of reliability even if you do get it running. You have either a geometry issue or a friction issue somewhere. I'd start by checking extractor tension to see if it is way too tight. That can slow down the slide as extra energy is used to push the round under the claw. I'd then pull the extractor from the slide and ensure that it has a smooth curve at the bottom. With the extractor out, also check the breechface and firing pin hole for any rough spots or burrs. Next step is to make sure the feedramp to chamber transition is smooth. My RIA had a super sharp transition that would actually shave the brass. I do think your recoil spring is excessive, but I do not think that it is the root cause of your problem. The above items all had to be addressed on my RIA. I am sure others will have different suggestions to try as well. Link to comment Share on other sites More sharing options...
zzt Posted January 29, 2018 Share Posted January 29, 2018 I use a 14 lb. spring for 172PF. 18 is too much. You can also put a small chamfer on the underside of the barrel hood. Link to comment Share on other sites More sharing options...
matteekay Posted January 29, 2018 Author Share Posted January 29, 2018 Good thoughts from both of you, thank you!The other thing I forgot to mention is that the gun has a Shok Buff in it that's starting to look pretty mangled. I imagine that that's not helping if the issue does stem from the mag not having enough time to feed a round. Link to comment Share on other sites More sharing options...
matteekay Posted January 29, 2018 Author Share Posted January 29, 2018 2 hours ago, IsaacB said: I'd then pull the extractor from the slide and ensure that it has a smooth curve at the bottom. With the extractor out, also check the breechface and firing pin hole for any rough spots or burrs. I wanted to hit on this one. I checked the extractor tension and that seemed good, but the bottom edge of the extractor looked pretty square. If I'm reading right, that should be sloped toward the top of the extractor, right? Any good pics of how it should look? I must not be getting the right combination of terms in Google to get a solid example... Link to comment Share on other sites More sharing options...
Beef15 Posted January 29, 2018 Share Posted January 29, 2018 If you search something like "1911 reliability mods" you'll come across some threads, articles, and pictures. Good clear graphics and pics are kinda hard to find. My Armscor upper had a sharp ramp to chamber transition, and everything is just a little rough, I've slowly been cleaning it up. Most all of it you don't really want to remove material just the minimum to reshape/smooth. Link to comment Share on other sites More sharing options...
matteekay Posted January 29, 2018 Author Share Posted January 29, 2018 Roger roger. I've used those "diamond" /rubber polishing wheels on my dremel to break hard edges on my revolvers - they work great and remove a minimal amount of material.Looking at my load notes... these rounds are running at 738 fps, so I'm not *completely* ruling out the recoil spring. I'll probably try lowering the spring rate, chucking the Shok Buff, and enhancing the extractor and mag-to-barrel transition. Link to comment Share on other sites More sharing options...
zzt Posted January 29, 2018 Share Posted January 29, 2018 Get rid of the buffer. Go to Brazos custom and read his magazine articles. Much good info. Here is the ling to ejection perfection. http://www.brazoscustom.com/Home.htm Link to comment Share on other sites More sharing options...
Steve in Allentown PA Posted January 29, 2018 Share Posted January 29, 2018 5 hours ago, matteekay said: If I'm reading right, that should be sloped toward the top of the extractor, right? Any good pics of how it should look? I must not be getting the right combination of terms in Google to get a solid example... This may help: Extractor fitting and shaping Link to comment Share on other sites More sharing options...
matteekay Posted January 29, 2018 Author Share Posted January 29, 2018 5 minutes ago, Steve in Allentown PA said: This may help: Extractor fitting and shaping Oh wow, does it ever. Thank you! Link to comment Share on other sites More sharing options...
matteekay Posted January 29, 2018 Author Share Posted January 29, 2018 See, I must be a visual learner. It took all of about 3 minutes to determine that I need to bevel/radius the belly and hook of the extractor, and that it's currently contacting the case's bevel and needs to be knocked back a hair. Thanks again! Link to comment Share on other sites More sharing options...
ltdmstr Posted January 30, 2018 Share Posted January 30, 2018 5 hours ago, zzt said: Get rid of the buffer. Go to Brazos custom and read his magazine articles. Much good info. Here is the ling to ejection perfection. http://www.brazoscustom.com/Home.htm I would not follow Brazzo's advice on how to set up the extractor. It is 100% wrong. Follow the link that Steve posted. It shows the correct way to do it. Link to comment Share on other sites More sharing options...
Chui Posted January 30, 2018 Share Posted January 30, 2018 Get rid of the buffer. Go to Brazos custom and read his magazine articles. Much good info. Here is the link to ejection perfection. http://www.brazoscustom.com/Home.htm Thank you for the link!!Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Postal Bob Posted January 30, 2018 Share Posted January 30, 2018 Replace the buffer first, then go to the other methods. In my custom .40 1911, when the rubber buffer gets torn up, it occasionally fails to completely go into battery. Link to comment Share on other sites More sharing options...
matteekay Posted January 30, 2018 Author Share Posted January 30, 2018 34 minutes ago, Postal Bob said: Replace the buffer first, then go to the other methods. In my custom .40 1911, when the rubber buffer gets torn up, it occasionally fails to completely go into battery. This one has close to 1k rounds on it and came out looking pretty sad. I'm going to run without one for a while. That being said, I don't understand why the buffer wearing in causes operational failures. Shouldn't the slide have more room to travel rearward as the buffer gets flattened? (Note: I completely believe you're right – I just need to see how things work in my brain, lol) Link to comment Share on other sites More sharing options...
Postal Bob Posted February 2, 2018 Share Posted February 2, 2018 It's not that there's more room for the slide to move back, but that the buffer starts bulging and expanding outwards. It starts rubbing against the inside of the slide and/or barrel, and slows down the slide going into battery. Link to comment Share on other sites More sharing options...
CocoBolo Posted February 2, 2018 Share Posted February 2, 2018 This is a good opportunity to revisit your ISO9002 ammo process. If you have a "failure to feed" and it is one in 100, well it is probably a small variance with your ammo, after all you did buy the cheapest bullet you could find, No?. Be more critical during the drop check! Make sure it is perfect else it goes into the practice bucket! Link to comment Share on other sites More sharing options...
matteekay Posted February 2, 2018 Author Share Posted February 2, 2018 1 hour ago, Postal Bob said: It's not that there's more room for the slide to move back, but that the buffer starts bulging and expanding outwards. It starts rubbing against the inside of the slide and/or barrel, and slows down the slide going into battery. Ah, roger, that makes sense. Link to comment Share on other sites More sharing options...
matteekay Posted February 2, 2018 Author Share Posted February 2, 2018 1 hour ago, CocoBolo said: This is a good opportunity to revisit your ISO9002 ammo process. If you have a "failure to feed" and it is one in 100, well it is probably a small variance with your ammo, after all you did buy the cheapest bullet you could find, No?. Be more critical during the drop check! Make sure it is perfect else it goes into the practice bucket! On that note, I'm also changing to Zero FMJ's from coated lead bullets. I love coated lead in my other calibers but the Square Deal B is a lot more finicky in terms of seating than my 650 is. I'm guessing I can make better rounds, faster, with the FMJ bullet. Link to comment Share on other sites More sharing options...
Absocold Posted February 2, 2018 Share Posted February 2, 2018 If the above doesn't solve the issue, closely examine the next stoppages and see if the rim of the round has even reached high enough on the bolt face to touch the extractor. If not (or even if it has and extractor problems have been ruled out), there are many things that can cause this. Some of the more likely: Feed ramp polish. Barrel throat polish or angle. Ramp to throat transition. Bolt face polish. Disconnecter too proud or incorrectly angled. Disconnecter ramp angle bad. Magazine too low or lips need adjustment. There are more but they are more rarely seen in a mass production gun. I'll save everyone writing a book, all of these can be googled individually I'm sure. i would start by hand cycling dummy rounds to try and reproduce the problem, then try the same thing with the extractor removed. Link to comment Share on other sites More sharing options...
Powder Finger Posted February 2, 2018 Share Posted February 2, 2018 1 hour ago, Absocold said: If the above doesn't solve the issue, closely examine the next stoppages and see if the rim of the round has even reached high enough on the bolt face to touch the extractor. If not (or even if it has and extractor problems have been ruled out), there are many things that can cause this. Some of the more likely: Feed ramp polish. Barrel throat polish or angle. Ramp to throat transition. Bolt face polish. Disconnecter too proud or incorrectly angled. Disconnecter ramp angle bad. Magazine too low or lips need adjustment. There are more but they are more rarely seen in a mass production gun. I'll save everyone writing a book, all of these can be googled individually I'm sure. i would start by hand cycling dummy rounds to try and reproduce the problem, then try the same thing with the extractor removed. also to add ..... burr around firing pin hole. Link to comment Share on other sites More sharing options...
matteekay Posted February 2, 2018 Author Share Posted February 2, 2018 I did check for that one (visually with a magnifying glass) but I'm going to try running a dental pick over that area to see if it picks (har har) up anything I missed. I finished round 1 of tuning the extractor and I have reduced power recoil springs on the way. I'm going to reassemble it with a 15lb spring for starters and see how it goes. Link to comment Share on other sites More sharing options...
Absocold Posted February 3, 2018 Share Posted February 3, 2018 5 hours ago, Absocold said: i would start by hand cycling dummy rounds to try and reproduce the problem, then try the same thing with the extractor removed. Seriously, this is the first step to diagnosis. If the problems continue with the extractor removed, I would first suspect the Tripp mags you are using are sitting too low or need the lips adjusted - in rare cases the mag catch may be out of spec but that's easily checked by trying the factory mags that came with the gun. If neither of these solve it, holler and we'll move on to the next step. Link to comment Share on other sites More sharing options...
Ken6PPC Posted February 3, 2018 Share Posted February 3, 2018 On 1/30/2018 at 10:36 AM, Postal Bob said: Replace THROW AWAY the buffer first, then go to the other methods. In my custom .40 1911, when the rubber buffer gets torn up, it occasionally fails to completely go into battery. There, I fixed this for you... Link to comment Share on other sites More sharing options...
Ken6PPC Posted February 3, 2018 Share Posted February 3, 2018 I mean, SERIOUSLY... What else does a buffer really do, besides limit the rearward travel of the slide, and make malfunctions more likely? 1911 buffers are a lot like most fishing lures - they are engineered to catch fishermen - NOT FISH! Link to comment Share on other sites More sharing options...
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