Do Drop-In Parts Really Drop In?

| Pistolsmithing |

By Ted Yost

I have to admit — usually when someone asks about drop-in parts, especially for the 1911, my initial response is not one of unbridled enthusiasm. In my line of work we place a great emphasis on the quality of the parts we incorporate into our work, as well as the best possible job of fitting or installation. Drop-in anything would then be a non-starter for a true custom gun.

But when Roy asked, “Are drop-in parts really drop in?” it made me think about all those kits sold. Do they really just drop-in? Could there be something to this? One thing’s for sure, there are few new stock pistols that can’t use a little improvement in the trigger department, so I decided to check it out.

I decided on a new Colt 70 Series as a test mule. It’s a consistent product and doesn’t typically have problems already built in. It does, however, have a pretty average trigger. This example varied between 4½ and 4¾ pounds with a little creep and lots of overtravel. I’d call it workable — but certainly able to be improved upon.

A quick look through Brownells reveals several drop-in trigger pull enhancement kits for the 1911. I settled on the Cylinder & Slide Super Match kit. They have several varieties, from tactical to match, and the kit I chose included a reduced-power mainspring, searspring and had some of the most beautifully machined action components you’ll find anywhere. The listing stated the pull weight would be 3.5 pounds. Since the kit includes a Commander hammer, I also chose a Wilson combat drop-in beavertail grip safety to provide clearance for the hammer and a more comfortable and consistent firing grip.

Final Function Check

The Cylinder & Slide kits come with clear, well-written instructions. There’s even a phone number connecting you to their tech staff if you encounter a problem. To complete the job, and to give yourself the best possible shot at reliable, consistent results, you might consider replacing the trigger too. Although a new trigger doesn’t fall into the drop-in category, fitting was covered recently in this column.

When changing the mainspring, wear eye protection, and be sure to hold the mainspring housing in a padded vise. This gives you control over the mainspring and prevents the launch of the mainspring cap and spring into space should things slip. Exercise caution when installing the hammer pin. Some fit very tightly, requiring a bit more force, so wear eye protection, and use caution with punches, as a slip or bounce with a punch can cause a mishit that might break the hammer.

The Wilson Combat drop-in grip safety did not simply drop in. That’s probably a good thing. It required minor fitting, both for at-rest trigger interference, and for clearance when depressed. While the Wilson part does not come with detailed instructions, Brownell’s has an excellent video on grip safety fitting.

One part of this exercise which is obviously not a drop-in is the thumb safety. If you’ve changed hammer, sear and disconnector, the chances are about 100 percent you’ve also changed the relationship of the safety with the sear. In many cases, a simple minor fitting of the safety’s lug will restore function. In other cases, the original safety will be too short to engage the sear properly, making a new safety necessary. Fitting a new safety isn’t hard — just remember to first familiarize yourself with the fitting process, go slow — because metal comes off a lot easier than it goes back on — and check your progress often. This is done by simply removing the grip safety and looking at the interface between sear and safety.


After some final work to get the grip safety to clear, Ted
found the trigger kit worked as advertised.

Take Down And Fitting

Once you’ve changed out the necessary components and reassembled your pistol, do two things. First, check the trigger pull weight to make sure you’re even in the desired ballpark and no further work is needed. Second, perform a full regimen of safety and function checks. You’ll need to test the grip safety, disconnector, thumb safety and overtravel stop to make sure everything is set up correctly.

If your pistol incorporates the Series 80 or Swartz firing pin safety, you’ll need to ensure these are also operating properly. As a final bench test, you’ll need to test for secure engagement of hammer and sear by dropping the slide on an empty chamber a few times. Everyone hates to do this, but it is necessary to detect trigger bounce or improper engagement of the hammer hooks and sear.

Only with all function and safety checks passed should you proceed to test firing, and then only load a couple of rounds at a time — just to be safe.

So, you ask, are the drop-in kits any good? I’d have to say you certainly get what you pay for, maybe a little more. Cylinder & Slide states the Super Match set will yield a 3.5-pound trigger. These parts, dropped into a new pistol, resulted in an extremely consistent 3.5-pound pull, exactly, measured by scale and static weight, repeatedly. There is very little creep, and a nice crisp break. Definitely a noticeable improvement.

But beware, in some (most?) cases, some fitting may be needed to get everything to work right.

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