1911 Govt length mags in compact frame

[Steve in Allentown]

I wanted to run standard CMI Government length eight round magazines in Officer's size frames so I bought a couple of their SBP Extended Bumper Pads which are used on their 10 round magazines to experiment with.



The next thing I did was disassemble a standard eight round mag, cover the bottom third of it with Dykem, lock it into an Officer's Model frame, and carefully use the bottom of the frame as a guide to mark its outline onto the magazine. Then I reassembled the mag and measured from the bottom of the mag pad up to the lines scribed into the Dykem and transferred those measurements to the new bumper pad.

After that it was a simple matter of cutting, filing, and sanding the polymer base pad until it allowed the eight round mag to seat into the Officer's frame. Now the eight round mags cannot be over-inserted, they run perfectly, and will be used as CCW spares on my belt.

Below are some pics of a Colt CCO that I tweaked a few years ago and one of my favorites for CCW (new sights, trigger, grip safety, slide stop). This first pic shows it with a standard, flush fit six round mag in place.




Here it is with a standard eight round mag fully seated. You can see the problem I was attempting to solve with my experiment. Over-insertion is definitely a concern here.




Finally, here it is with the same eight round mag seated but with my homemade bumper installed. A perfect fit, if I do say so myself. Problem solved.




Below are three magazines so you can see the differences. Standard flush fit six round, standard eight round extended tube with standard bumper pad, and standard eight round extended tube with homemade bumper pad.




Below is what the SBP Extended Bumper Pad looked like before and after my surgery on it.

 

[Steve in Allentown]

I left out one picture. Here's a pic of the Dykem applied to the first mag. If you look closely, you can see a thin white line where I scribed the outline of the frame onto the mag. This is an Ed Brown branded Check-Mate magazine.

 

[larryh1108]

Clever fix!
However, they make an extension called X-Grip for just this.
Just a head's up.

 

[Steve in Allentown]

However, they make an extension called X-Grip for just this.

I appreciate the heads-up but I was under the impression that it only worked with certain magazines like the ACT-MAG or similar. I'm not sure it will work with the Check-Mate 8 round, extended tube mags that I strongly prefer.

 

[larryh1108]

Good question. I never bought one.
I bet someone here has used them.

 

[earlthegoat2]

Over insertion?

Does this only apply when the slide is locked back?

 

[Steve in Allentown]

Over insertion? Does this only apply when the slide is locked back?

Sort of. With the slide open a magazine that doesn't have a physical stop that will prevent it from going beyond the magazine catch will lock up a pistol tighter than a drum. With the slide closed the same magazine can't get high enough to stop slide movement (with one exception). However, if the mag doesn't have a physical stop incorporated into the base pad it can be pushed high enough to contact an extended ejector. Repeated pounding of this part will result in it being bent or broken. I consider this to be over insertion also.

There's not much you can do with a welded base, flush fit magazine to stop over insertion unless you can add metal on top of the tab that sticks out in front of the mag then file it down until it just touches the corresponding notch in the pistol frame when the mag catch locks into the mag catch cut out in the mag body. But with removable base pads that are a bit oversized you can file them down to get that perfect fit. Also, when building a 1911 I always pay close attention to the frame's base plate notch to be sure it is the correct depth to prevent over insertion.

The one exception I noted is if there's a mismatch between the design of the magazine and how high the mag catch holds the magazine in the well. I normally install an EGW higher mag catch in all 1911s to enhance feeding. But doing so results in most McCormick mags coming into solid contact with the underside of the slide because the mag is designed with a high wall ahead of the feedlips. This contact is enough to impede free slide movement. The cure was to simply file down that high wall ever so slightly. Chip's mags were the only ones I ever ran across that did this.

 

[Steve in Allentown]

What I failed to point out in my original post was that the 8 round mags are back ups carried on my belt that will be put to use if the first seven rounds out of the pistol aren't sufficient to solve the problem at hand.

I find that I can manipulate these 8 round mags faster during reloads than the shorter, flush fit mags made for compact frames.

 

[Steve in Allentown]

I recently modified ten more base pads so I could have more 8 round mags that would correctly fit compact frames like Officers and CCO pistols.

Rather than measuring this time, I simply used one of the previously modified base pads to trace a line onto my next victim.




Cutting was faster using a sawzall blade by hand after first scribing along the line using a Dremel cut off wheel. The Dremel melted the plastic if held in place too long so I lightly cut a groove that would keep the sawzall blade lined up.



Here's a base pad with one side removed down to the scribe line. You can see the opposite side has been cut through also. All it needs now is a vertical cut to intersect the horizontal cut so that section can be removed. You can also see a cut at the front where the new front tab will be located.



Here are 10 base pads that have been "roughed in". At this point they've all been fit so that there is minimal clearance between all three contact areas on each of them them and the pistol frame. This is much stronger than just the single contact point at the cut out at the front of the frame common to all magazine manufacturers. You could pound a magazine into the frame with a ball peen hammer and these base pads would probably withstand the punishment much longer than any other method of preventing over-insertion.

It took lots of filing and sanding to get to this point. The finishing touch of polishing the cut surfaces comes next.



Here are two pistol cases loaded up with standard 6 round mags and 8 round mags with their new base pads. One case is for a CCO while the other is for an Officer's Model.

 

[wally]

Over insertion?

Does this only apply when the slide is locked back?

Yup!.

 

[wally]

I recently modified ten more base pads so I could have more 8 round mags that would correctly fit compact frames like Officers and CCO pistols.

Love those Midway pistol cases! I've got them dedicated to all my range favorites.

 

[Steve in Allentown]

Over insertion? Does this only apply when the slide is locked back?

Yup!.

See my reply to this question in Post #7.

 

[bannockburn]

Steve

Nice work with the magazine extensions; well thought out and finished.

Like your Colt CCO too!