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Old June 19, 2020, 08:31 PM   #1
Steve in Allentown,
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Join Date: December 5, 2010
Posts: 188
1911 - Why is it so hard to seat the magazine and how do I fix it?

The normal operation of locking any fully loaded magazine into a 1911 pistol with the slide forward should require no more force than that which can be applied by pushing it into place using one thumb.

If a ball peen hammer is needed to lock it into the pistol, you’re going to be at a serious disadvantage if you ever need to perform a reload during a match or on the street.

Ignoring the magazine catch for the time being, there are four major areas that need to be checked to determine why a magazine cannot be easily seated.
  • Spring stacking
  • Base plate contact
  • Ejector contact
  • Slide contact


As shown below, the magazine spring (blue) becomes more and more compressed as more and more rounds are loaded into the magazine. The standard flush fit magazine for use in full length 1911 frames was designed to hold seven .45 cartridges. When it is filled to capacity the coils of the spring will still have space between them. This allows the spring to easily compress more when the column of cartridges is pushed further down when the top round comes into contact with the slide’s disconnector rail (aka the stripper rail) as the magazine is seated.

With the advent of eight round flush fit magazines the issue of hard-to-seat fully loaded magazines has become common. These magazines have no more available internal space than the standard seven round magazine so design compromises had to be made to allow eight rounds to fit into a space designed for seven rounds. This resulted in much less free space between the spring coils to allow for additional compression.

Depending on the geometry of a specific pistol, the spring coils in these flush fit eight round magazines may be forced into hard contact with one another as the top round in the magazine is forcefully pushed up against the disconnector rail. This hard contact between the coils creates a solid column of steel which will not compress further. The result is failure-to-seat the full mag as well as shortened spring life. Given the application of enough force over time the magazine base plate may fail.

So, if you have a flush fit 8 round magazines that will not easily seat, only load seven rounds into them. Note that many pistols do not have this issue.

Magazine identification in the picture below from left to right:
  • flush fit 8 round Check-Mate
  • extended 8 round Check-Mate
  • extended 8 round Tripp
  • extended 10 round Check-Mate

Note that the magazine tube of the flush fit Check-Mate does not extend below the frame hence the term “flush fit”.

Each of the three extended magazines in the picture above has a tube that protrudes noticeably below the frame. These magazines have enough room to hold the specified number of rounds without over compressing the spring. These fully loaded magazines can easily be seated using one thumb.

If you want to have more than seven rounds in a magazine, keep it simple and get a magazine that was designed from the ground up to hold the number of rounds you want.


Over insertion of a magazine into a pistol is not good. The result can be a bent / broken ejector or a pistol that is completely locked up and out of the fight.

Over insertion is prevented by one thing in the 1911 design: the nose of the magazine base plate that extends forward of the magazine tube. Pictured below is a magazine that uses a nylon base plate (aka bumper pad). The nose of the base plate (blue arrow) fits into a corresponding cut out in the frame (red arrow).

Depending on the dimensions of a specific pistol and a specific magazine it’s possible that the frame cut out isn’t deep enough to allow the magazine to be seated. If this happens with a flush fit welded base plate magazine, the frame cut out can be deepened with a file.

I have never seen this with a factory pistol. I've only ever seen this with after-market magazine wells that were attached to the pistol.

If this happens with a nylon base plate, the nylon can be filed or sanded down (blue arrow). You’ll know you have a good fit between the magazine base plate and the frame cut out when the empty magazine has a small amount of up and down slop when it’s locked into the pistol.


Contact between magazines and GI ejectors is not possible since that ejector does not extend over the magazine well as you can see in the picture below.

However, this is not uncommon with extended ejectors. Repeatedly slamming a magazine into the pistol without correcting this condition will eventually result in the bending or breaking off of the ejector nose. In the worst cases the magazine will be forced up beside the ejector and be solidly wedged in place. This often requires the use of tools to remove the magazine from the pistol. I have seen this happen too many times during local club IDPA matches.

Picture “A” below shows contact between a fully seated magazine and the ejector nose. Picture “B” shows the same magazine after the ejector was relieved to eliminate the contact. Not shown is the magazine with a cartridge in it. The cartridge was also making contact with the ejector so the ejector was further relieved to eliminate that contact and the clearance seen in "B" was the result.

To determine whether or not there is contact with the ejector remove the magazine catch, remove the slide, push the magazine as high as it will go in the magazine well and hold it there while observing its position relative to the ejector. Repeat the exercise with a cartridge in the magazine. In either case no contact is allowed with the ejector.


In rare instances the right side of the top of the magazine tube ahead of the feed lips may come into contact with the underside of the slide keeping the magazine from easily locking into the pistol or preventing it altogether. I’ve only run into this in certain pistols with the combination of EGW Higher magazine catches and McCormick magazines.

To test for this condition remove the magazine spring and follower, remove the recoil spring, remove the disconnector, and install the magazine catch. Pull the slide all the way to the rear, lock the magazine tube into the pistol, and slowly ease the slide forward while being alert to any indications of contact between the slide and the magazine tube. There should be no contact between the slide and the magazine tube. This condition can be so severe that the slide will not close.

The fix is to not use an EGW Higher mag catch, not use McCormick mags, or file down the magazine’s contact point with the slide. Understand that this is not an indictment of either EGW or McCormick. They are both excellent products but using them together in some pistols may result in unwanted slide/magazine tube contact.

Last edited by Steve in Allentown,; June 20, 2020 at 04:43 PM.
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Old June 19, 2020, 11:37 PM   #2
Aguila Blanca
Join Date: September 25, 2008
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Excellent summary. Well done.

IMHO, flush-fit 8-round magazines are an abomination. If John Moses Browning had thought the magazine would hold 8 rounds, he would have designed it for 8 rounds. I doubt very much the Ordnance Department would have said, "Well, that's a nice pistol, Mr. Browning, but could you please reduce the capacity by one round?"
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Old June 20, 2020, 02:06 AM   #3
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The source of the issue is the 8-round magazines used. The 1911 pistol was first issued with a 7-round magazine. 8-round magazines became a thing in the late 1980s, prior to that time I never met anyone who had trouble locking a loaded magazine in place on a 1911. Never. People thought it would be a good idea to have an extra round for IPSC and IDPA, so they made it happen. But before that time, I never heard of an 8-round 45ACP magazine for a 1911. So you can modify the pistol that is not the source of the problem or use the pistol the way it was intended.
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Old June 20, 2020, 09:08 AM   #4
Steve in Allentown,
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Originally Posted by Scorch View Post
So you can modify the pistol that is not the source of the problem or use the pistol the way it was intended.
Thanks for your feedback. You and I are on the same page.

As a result of your comments I edited the post to make it clear that I've never seen a factory 1911 that had a problem with the magazine floor plate notch not being deep enough. I have seen this problem with pistols that have had after-market magazine wells attached to them.

The only other modification to the pistol that I covered was relieving the underside of extended ejectors to eliminate contact with the magazine or the top round in the magazine. We both know that a GI length ejector as designed by JMB could never contact a magazine or the top round. So, the modification only applies to extended ejectors that are commonly found in commercially manufactured 1911s these days.
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Old February 5, 2023, 09:44 AM   #5
Steve in Allentown,
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Join Date: December 5, 2010
Posts: 188
Originally Posted by Steve in Allentown, post: 2239552
Ignoring the magazine catch for the time being . . .
It's time to stop ignoring the magazine catch as a potential factor for difficult magazine seating. Once again we're looking to be able to fully seat a magazine using no more than the strength of single thumb.

The magazine has to push the catch sideways. For this to happen the catch must be shaped appropriately. It is not unusual for a magazine catch to have geometry that doesn't allow a magazine to be pushed past it.

In the left picture of the two below the red arrow is pointing at the area where repeated magazine contact has created a rough surface. If you look closely, you can also see the wear at the bottom of the catch caused by repeated magazine contact. No magazine from any manufacturer could be seated in this pistol even using a firm palm smack unless the catch was pushed inward.

To solve this problem the first thing to do was to coat the entire area where magazine contact was possible with Dykem as shown in the right hand pic below. This is followed by repeatedly seating a magazine to scratch away the blue Dykem so you can see exactly where the modification needs to happen.

Once I identified the problem areas, I roughed in a bevel where magazine contact was occurring as shown in the pic on the left below. I used a #2 cut file for this operation. This was followed by a #4 cut file, 320 grit sandpaper, 400 grit sandpaper, and a felt wheel in a dreaded Dremel tool. The result is shown in the right hand pic. The white arrow is pointing out the poor machining of the part.

The end result of my efforts was the ability to seat the magazine with the use of a single thumb. It should be pointed out that each magazine catch may require a different degree of modification depending on how it was machined and which magazines are to be used. For example the Wilson, Tripp, and McCormick mags that I have on hand do not have the same relieved area on the right side of the magazine tube like CheckMate mags have to allow for easier insertion past the mag catch.

Below is another mag catch that was modified. This one only required the edge of catch to be rounded. Note that the shelf that engages with the magazine slot is rounded at the extreme rear edge of the catch. This can also been seen in the pics above.

In some instances a lighter than standard magazine catch spring will be needed to optimize magazine seating. Wolff Gunsprings offers a 5 spring assortment pak of these springs each of a different weight so you can use the one most appropriate for your circumstances. I've generally used the #2 spring. Be advised, using too light of a magazine catch spring will allow the magazine catch to move enough to allow the magazine to drop out of the pistol during live fire especially when firing hot loads.
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