wsimpso1 Posted November 17, 2005 Share Posted November 17, 2005 Hi, I am just finishing up the build on a the limited gun, and the gun was feeding for crap. Read the FAQ's, did a search, broke all of the hard corners, set the widths between feed lips at 0.385-0.395", polished the front edge of the lips. While hand cycling the gun, it still wants to hang up some rounds on the feed ramp - the rounds are aimed such that they still hit the feed ramp, but only barely. It is so much better than before. It will not hang if I just drop the slide, but if I follow it down it can hang. I can probably open the lips a wee tad more (to 0.395") and get the nose of the round pointed higher if I have to. Then when the round does enter the chamber, I can still get it hung up with the case on the break between feed ramp and chamber and the rim still under the last 0.040-0.060" of the feed lips. My McCormick mags in my Colt in .45ACP release the round with nearly 1/8" of clearance and it is 100%. Hmmm. So I am wondering, should I take a bit off of the front edge of the feed lips in order to release the round at the right time and beat this failure? Shortening the lips would also improve the leverage for making the bullet ride up the feed ramp, so I can only see advantages here. Is there soemthing that I can not see that will bite and cause me to scrap any mags modified in this way? Billski Link to comment Share on other sites More sharing options...
ima45dv8 Posted November 17, 2005 Share Posted November 17, 2005 Something to consider: You won't be easing the slide forward when you're shooting it. I've had a few guns that were sticky when hand-cycling the action, but ran great when shooting them. That's the acid test. If it runs, ya done good. Link to comment Share on other sites More sharing options...
benny hill Posted November 17, 2005 Share Posted November 17, 2005 Sound's like a feed ramp & chamber problem, not a mag. If you are going to shoot a lot of matches, spring for a few buck's & let a pro set it up right & then just enjoy it. Link to comment Share on other sites More sharing options...
bulm540 Posted November 18, 2005 Share Posted November 18, 2005 DITTO!!!! Link to comment Share on other sites More sharing options...
rack&roll Posted November 19, 2005 Share Posted November 19, 2005 +1!!! Benny Hill set up my STI Limited gun, and it runs like a scalded dog! After many attempts to have different local 'smiths fix my gun so it would work, I finally gave up on it. Many months later, after hearing so many good things about Benny and Triangle Shooting Sports, I decided to bite the bullet (no pun intended), and send my gun to Benny via Fed-Ex. It's the smartest money I ever spent on a gun! Turn around time was FAST, and the price was more than reasonable. Benny is a great guy, listens to your problems, and is very easy to work with. Bottom line is...my gun works flawlessly now. Not a single jam or malfunction in almost 1000 rounds since I got it back. If you really want it done right send your gun (and mags) to Benny Hill. You won't be sorry. Benny, if you read this, thanks again! Larry Link to comment Share on other sites More sharing options...
wsimpso1 Posted November 19, 2005 Author Share Posted November 19, 2005 I know that Benny is a great gunsmith and shooter, nearly unbeatable with a long gun, etc. I also know that many of you believe in working with a great 'smith and then just shooting your gun. And maybe that is the best advice... Thank you. What I really wanted was knowledge on how to make mags work or knowledge that would convince me that fooling with mags is just not wise. Heck, I am an engineer working on automatic transmissions, and I will help pull one, but I let the pros do the rebuilds. I know, reliability tuning is the realm of the pros, and how they make their living, that they are not interested in giving away for free what people would otherwise pay for, etc. Now me, my first job after engineering school was Remington Arms. Besides arming me with gobs of good info and almost ruining a good hobby, it made me lust for doing my own work on guns. I have successfully built very accurate, reliable rifles for High Power (M-1's, AR15's, Bolt Guns), and modified my old .45 into a completely reliable accurate Ltd10/CDP. Now I have made a LTD/ESP gun and am trying to make it go from 98% to 100% reliabilty. So, if anyone has advice on mag tuning, I am still listening. Billski Link to comment Share on other sites More sharing options...
ErikW Posted November 19, 2005 Share Posted November 19, 2005 I'm with 45dv8... leave your mags alone and don't rely on hand-cycling as a test. If it does the same thing live firing, use a heavier recoil spring. Link to comment Share on other sites More sharing options...
benny hill Posted November 19, 2005 Share Posted November 19, 2005 If your mag lip's are at about .375/.380, lock in & drop free & load easy to 18 rds & have ISMI springs, you have great mags. check your crimp at .418/.419 & your good to go. good luck. Link to comment Share on other sites More sharing options...
Radical Precision Designs Posted November 20, 2005 Share Posted November 20, 2005 Sound's like a feed ramp & chamber problem, not a mag. If you are going to shoot a lot of matches, spring for a few buck's & let a pro set it up right & then just enjoy it. So you say you like to tinker and have the background and know-how to do it. I see your point, having spent the time studying mech. engineering myself many moons ago before I did my initial learning stint with firearms. I guess you have enough 'on hands' experience to understand that usually the headache has nothing to do with your head itself. That said, as BennyHill pointed out, you need to address the areas highlited in red above. Leave the mags (bodies) alone unless they are malfunctioning, or "really not working properly, if they indeed are "up to manufacturers specs". Relieving the lips the way you suggest, if done improperly or leaving too little to hold the cartridges will only allow the mags to jump/spill the cartridges as they hit the ground during reloads, and sometimes even "double-feeding" jams/spitting out, during normal firing. Link to comment Share on other sites More sharing options...
wsimpso1 Posted November 22, 2005 Author Share Posted November 22, 2005 Thanks Benny, the dimensions for crimp and feed lips is VERY useful, and confirmed my feel for where they needed to be. I stopped short of the 0.395" at the front of the lips recommended in another thread, and now they are about 0.380-0.385". With the lips set to those dimensions and the hard corners removed from the front edge of the feed lips these guys run very nicely by hand and so far are 100% in the gun. They do not fountain or spit rounds either. I am still concerned that the release may be a bit late, but I will stop fussing and just shoot the thing. Thanks again, Billski Link to comment Share on other sites More sharing options...
wsimpso1 Posted December 4, 2005 Author Share Posted December 4, 2005 Followup - With the front edge of the mag lips at 0.385", sharp edges broken, front 0.10" of each feed lip polished lightly, and the slide stop surface adjusted to lock the gun open at the right place, these mags run 100%. The length of the feed lips did not need to be shortened at all. Thanks again for the help. Billski Link to comment Share on other sites More sharing options...
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