Question About Feed Ramps

A reader e-mailed with a question about the use and actual shape of feed ramps in modern pistols. He had apparently witnessed a catastrophic failure in a popular brand off semi-automatic pistol chambered for the 9 mm Luger cartridge. From this, he had begun to believe that certain types of so-called “unsupported” feed ramps were inherently unsafe and the use of supported ones would eliminate failures of this type. First of all, the use of some kind of feed ramp is virtually required in all pistols for efficient operation, with some feed ramps integral to the barrel and others in the receiver. Some manufacturers even build a feed ramp into the magazine. I genuinely believe that no maker (and certainly not the one the reader had named) would ever offer a pistol for sale that had a dangerous design flaw. There is simply too much at stake. The design of a particular feed ramp is developed to achieve efficient operation and not to cut corners.

In the same light, the reader's request for a listing of the type of feed ramps used in common pistols is beyond the research capabilities of this author. I would need one of all of them and I don't have them. As it turns out, the reader was concerned—and understandably so—about the use of handloaded ammunition in his guns. I used to be an avid handloader and wrote a number of articles on the subject. Unhappily, that is not something with which I am deeply involved with these days. However, I can recall the elaborate care that went into everything I did at the handloading bench, as well as when I was writing on the subject.

It is possible to go out to my loading shop and assemble something that will immediately destroy a top-quality gun. This, however, would have to be an accident, because I have instituted careful checks and double-checks into my reloading practices. But, I have no control whatsoever over what you are doing, so I can only tell you to follow established practices described in every handloading manual ever printed.

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4 Responses to Question About Feed Ramps

Gary wrote:
February 22, 2012

So how much pressure are you expecting your unsupported brass case to hold? Here are the Maximum Average Pressures (in PSI) from SAAMI: 9mm 35,000; 9mm+P 38,500; .40 35,000; 10mm 37,500; .45 21,000; .45+P 23,000; .44 Magnum 36,000. Were you surprised to learn that common pistol cartridges generate pressures in the .44 Magnum range? Feel like firing off 6 rounds of .44 Magnum in a cylinder sans complete chamber support? From the silence generated by this post, I assume that most of you are just going to ignore the problem. For those that are reloaders, here is a simple test you can perform that might justify, in your eyes, the reloading of a case fired in an unsupported chamber: After a day at the range, take home your empty brass in a plastic bag. When you clean your weapon, remove the barrel. Take each one of your fired brass cases and insert them into the chamber. Rotate the case 360 degrees plus a little more. The idea is to prove that the case does not have a "bulge" originating from the 6 o'clock position by rotating freely without even a hint of friction. The cases that fail the test get smashed and discarded. Wouldn't it be a lot simpler (and safer) if we just had fully-supported chambers?

Gordon wrote:
February 21, 2012

As I understand the feed ramp isue. The feed ramp on the berrel should not be forward of the web of the case, if it is then the barrel is not safe to shoot. This also address the manufacture of the brass. If the web of the case is to short then the feed ramp will be forward of the web and will not support the brass. That is one reason to have a qualified Gun Smith perform any ramp pollishing.

Fred wrote:
February 18, 2012

Mr. Clapp, I have several Glocks in 9mm, a military 1911 .45, and the feed ramps are mirror smooth, and all function flawlessly. When I purchased my Ruger LCP, I thought the surface of the feed ramp was a little rough, so I cranked up the Dremel tool with a felt polishing bit and some jeweler's rouge and shined it up. I've probably run 5 boxes of .380's of every brand and description through it and the only problem I've had was 1 stovepipe from limp wristing it. I'm sure it would have polished naturally after breaking it in, but I felt secure in my expertise to perform the work.

Gary wrote:
February 17, 2012

Let me simplify this problem. When I was preparing to buy a .40 pistol, I honored the advice in the reloading manuals and purchased a pistol with a fully-supported chamber because I was going to reload for it. The .40 case is a "little weak" in the head area and needs this supportive help. Now, and this is important, this pistol feeds 100% and doesn't need a feed ramp that destroys the chamber. Amazingly, this same manufacturer doesn't use a fully-supported chamber in their 9mm offerings and that is the caliber that went KaBoom. In fairness to the company, it was a factory reload that caused the problem. So the essence here is how to PRECLUDE KaBooms, even with reloaded ammunition. Now reloading involves "work-hardening" the brass, more so in a chamber that allows more expansion in the head area because there is no support at the 6 o'clock position. Instead of the now-weakened case being backed-up with steel, you are at the mercy of that weakened case being required to hold all the pressure. Now, and this is the point of the entire question: IF A MANUFACTURER CAN PRODUCE A 100% RELIABLE PISTOL IN .40 WITH A FULLY-SUPPORTED CHAMBER, WHY CAN'T THEY USE THAT SAME EXPERTISE TO MAKE THE REST OF THEIR CALIBERS WITH A FULLY-SUPPORTED CHAMBER? If their pistols can't feed with it, then OK. Just tell us in your specs and then we will have the choice of moving on to another company that has mastered the problem. I can't think of anybody that would buy a revolver with part of the chamber missing in hope that the case would hold. I believe that the manufacturers build to load and fire one new round without support because that's what the case is designed to do. Now before everybody writes in that they have fired thousands of reloads in their unsupported chambers, that still misses the point: WHY CAN'T THEY MAKE ALL THEIR PISTOLS "EXTRA" SAFE SO WE DON'T HAVE TO SWEAT IT? Thanks to Mr. Clapp for having the guts to even mention this question out loud. He really cares!