Since a couple have asked about it, I thought a little quick seminar on magazine release timing would be in order. Keep in mind that the magazine is not an accessory. It's a removeable, disposable part of a system in which each part works with another part...often as a redundant or backup...to the other. Browning was the master or redundant function. The magazine and all related areas of the feeding phase are the epitome' of that.
As we know, the 1911 pistol was designed with controlled feed as a criteria. The cartridge should be fully and positively under control from the instant that the slide touches it until it's in the chamber. If at any point in the feeding phase, that control is lost, the liklihood of a malfunction is greatly increased. Not guaranteed...but increased. Reliability isn't about guarantees. It's about reducing the odds of a failure. Anything can malfunction. All we can do is strive to see that it doesn't...and we do that in large part by insuring that every round is under control until the empty case clears the port.
I've often mentioned that the more recent wadcutter-type magazines release too early and too abruptly...but without really delving into exactly why that's a bad thing. The early, abrupt release point is fine for the short cartridge OAL
that comes with correct seating depth of some styles of SWC bullets. Even though those rounds do misfeed occasionally, even in a well-tuned gun...because they were intended for target ranges...an occasional misfeed during a match isn't the problem that would be if the gun is the only thing between you and the morgue.
Simply stated....the release point should come after extractor pickup is well established. Once that's been accomplished, it can release gradually or abruptly with no loss of control. Well-established being the key phrase here...it doesn't mean that the rim is barely under the corner of the extractor. it means that it's at least halfway there...with the rim under the claw, and the bullet ogive well into the chamber.
Here is where the tapered/gradual release design comes into its own. By allowing the rear of the cartridge rise nearly parallel with the front, the approach to the chamber is straighter, with less angle to overcome while it breaks over to the horizontal plane. This serves to reduce the amount of stem binding that's present with the parallel/early/abrupt release wadcutter magazines...which don't allow the rear to rise. That forces the round to climb the feed ramp at a sharper angle.
When the round approaches the release point at a steep angle, the rim is also at a steep angle relative to the extractor. If the extrator has a sharp corner on the bottom, it can contact the inside of the rim, and cause a failure to go to battery. Radiusing the corner helps, but it doesn't address the whole problem.
When the round releases too early and too abruptly, all that keeps it from getting ahead of the extractor is the extractor itself. When the bottom corner has been radiused too heavily...the corner may miss the rim as it pops up...and we have the classic push-feed. If the claw snaps over the rim, the gun goes to battery. If it doesn't...it stops dead without the ability to extract the round with the "Tap-Rack-Bang" drill...and that malfunction is slow to clear in an emergency. Bad JuJu.
Enter the extractor modification in which the bottom of the claw angles forward to aid in recapturing the rim should the slide knock it ahead of the optimum pickup point. It works well most of the time if correctly done...and enhances the odds that the extractor can catch up to a loose round and sort of "funnel" it back into the claw.
The point is that all these modifications became necessary because of the desire to shoot short semi-wadcutter ammunition at targets. The short, abrupt release point...the extractor prep...and the ammunition all go hand-in-hand. How it came to be SOP for all guns and all extractors and all magazines is still a mystery to me.
Only Colt stuck to the proper magazines for conventional ammunition. That is...cartridge OAL of 1.200 or more, with ball-like bullet ogives...and of course...7-round capacity with proper follower design. Given that Colt has been building the gun non-stop for almost a century, common sense and logic may should lead us to acknowledge that Colt probably knows a little more about the gun than many would suspect. I can promise that they know more about it than most of the aftermarket entrepeneurs who mount a campaign to convince us that we "need" this or that new/improved product. i.e. :If your pistol doesn't have THIS (pick one) then you NEED this pistol!"
When the magazine release is correctly timed, it feeds the rim gradually and in a controlled fashion into the extractor pickup point...resisting the slide's impact and keeping the round in contact with the slide rather than being knocked forward of it. The bullet nose is in contact with the feed ramp, and is being cammed upward. The rim is also rising as it moves forward in the tapered lips...both being pushed upward by the magazine spring. This push is even and nearly parallel front to rear, unless the follower pitches forward, and effects a nose-dive into the ramp...causing the round to climb at a sharper angle.
When the release point is correctly timed, it hands the round off, and when it finally gets free, the angled breechface takes over and continues to let the rim come up gradually...under resistance...to keep it in contact with the slide as the round makes the final bit of breakover into the chamber. The magazine and the breechface are redundant features that compliment and back one another up in the event that either is less than optimum. Of the two, the magazine is the more critical. You can find happiness with a vertical breechfacce and a late/gradual release magazine than with an early/abrupt release magazine. You can also find it with a correctly angled breechface and an early/abrupt magazine...but just not with the same bet-your-life reliability as when both are within spec. Here is where the intermittent malfunction comes from. The one that has no rhyme or apparent reason, and occurs so infrequently as to cause us to chalk it up to fluke or bad ammo...but there's a mechanical reason for it all the same...and it's usually the magazine.
If the gun and the magazine are within spec...assuming a good extractor that's properly tensioned...the average man will seriously deplete his bank account in an attempt to buy enough factory ball ammo to cause a misfeed.
I have a pair of ORM 1991A1 Colt 5-inch guns that are within spec in all critical areas. I've used nothing but 7-round magazines since day one...and mostly Metalform's "wadcutter" designs. The pair has over a quarter-million rounds collectively. They've been through one complete rebuild/refitting, and are both on their third barrel. 95% of the ammunition has been my reloads...and 95% of that has been with my home-cast and commercially produced cast lead...of all shapes and descriptions. One has never malfunctioned other than the one time that it failed to lock empty due to a broken slidestop lug. The other has had maybe a half-dozen...attributable to the ammo in all but one...and that one was due to a cracked magazine...in 15 years of hard use. Neither pistol has lost an extractor...ever. They've gone up to 75,000 rounds without even a need for retensioning the extractors until recently when I finally tossed a batch of brass which had rims so badly oversized that the extractors took a set on the diameter...and when I switched to a new lot of once-fired brass, the ejection was a little weak. No failures to eject...but just a little weak. I did retension at that point...almost a year ago...and have had zero failures to extract or eject.
I have another beater that required a little tuning. A NRM Colt that had an MIM extractor. I relpaced it with a used USGI extractor that came out of a junker 1918 B;ack Army Colt. 30,000+ rounds without a failure. I attribute this awe-inspiring performance mostly to the magazines, and take just a little credit for the tweakin'...which was very little. No "Ramp and Throat" work...No mirror polishing...No voodoo or magic tricks. The feed ramps are
far below what most smiths consider minimum...at .300-.320 deep.
Magazines...Extractors...Ammo.
Check-Mate industries has stepped forward and said that if we want'em, they'll supply'em...and without having to go through the middle man to get'em. These tapered hybrids that they make are the best of the best, and I strongly advise one and all to take advantage of it. If your gun won't run with these...you've got bigger problems than a magazine can cure.
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Originally Posted by auto45
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