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I wanted to run extended tube CMI Government length eight round magazines in Officer's size frames so I bought a couple of their SBP Extended Bumper Pads which Check-mate uses 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. 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.

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.

Every mag I have gets heavily used on the range and during IDPA matches. These are no different. In fact, the eight round mags that have these new base pads have already seen hundreds of rounds through them with no malfunctions.

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.
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