Perhaps you already have a Sig Sauer P320 and are looking to get a weapon mounted light. While there are lots of good options on the market, the Inforce APLc is a popular one because of a few reasons.

The light itself is small, and has a mostly snag-free design. This is an important carry consideration as designs with big levers or arms can snag on clothing and necessitate a larger holster to carry.  The light has 200 lumens, which is adequate for most situations (I would advocate carrying a handheld light as well for situations where you don’t want to point your pistol at something you wouldn’t want to shoot — but that’s a whole different topic), and the runtime is adequate at 1.5 hours.  Finally, the switches are available on both sides, allowing you to manipulate with strong hand or reaction hand.  This all adds up to a very popular package for users.

But there are 2 different versions of the APLc.  There is an “APLc” and “APLc for Glock“.  The difference between the 2 is not immediately obvious, but if you look close, you’ll see that the APLc for Glock places the screw (which goes through the rail slots) further forward than the regular APLc.

This might make you think that you must purchase the APLc for your Sig Sauer P320. However, that is not the case.

As you can see from the above pictures, the screw may be positioned differently, but the light appears to be mounted in the same position.  Why is this?  It’s because the APLc for Glock and the APLc simply have their screw travel through different rail slots; the rail slot spacing is the same as the spacing difference between the different versions of the APLc.

Why is this important?  Say you have a number of different pistols you may choose to use your weapon mounted light with?  Perhaps you’re not sure if you’re going to run your APLc on your Sig or your Glock?  You can purchase the APLc for Glock, and use it on either pistol.  Similarly, perhaps you’re wanting to switch your light between the P320 and the HK VP9sk (the APLc for Glock won’t fit this HK), then get the regular APLc and you’re covered.

While this article is in relation to the popular Sig Sauer P320, it likely applies to a number of different pistol models.  If you choose carefully, you can maximize the interchange of your APLc on various pistols.

Here is a video showing what is discussed above.