A few weeks ago, we took a first look at the Walther PDP and how it's optics mounting system has been revised by Walther after receiving some feedback from owners about the possible flaws in its design. Today, we're going to go ahead and mount an optic on the PDP and talk about some other steps to take/considerations you should think about when mounting an optic, especially if it's your first time.
First though, is a quick overview/recap of how the "second gen" PDP optic mounting is different from the first generation:
Originally, Walther designed the PDP with an optic system that had the bottom of the mounting plate as well as the pocket of the slide both completely smooth, so that the only interface between them was the screws that were holding the optic and plate in place. This resulted in all of the force of the slide reciprocating being borne by these optic mounting screws, which are not the best at bearing a sharing force. Some owners had these screws fail or break, and subsequently had their optic detach from the slide.
Walther has subsequently redesigned the optic mounting system for the PDP, and has incorporated sections in the slide and on the optic mounting plate that interface together and take the stress off of the mounting screws. Most notable is the large center spine that runs down the middle of the slide pocket and its corresponding slot in the optic plate, as well as the locating lugs on the plate and their corresponding areas on the slide. Together these mitigate the side-to-side forces as well as the fore-and-aft forces that are exerted on the mounting system, allowing the screws to simply secure the plate to the slide.
Mounting the optic starts with making sure that you have the correct plate for your optic. Optics have different footprints, and each mounting plate is footprint specific. Most optics will tell you which footprint they have, either somewhere on the packaging or through some quick searching online. It's critical that the optic plate you have match this footprint, or the optic will never mount correctly.
It is worth it to note that the plates do not ship with the PDP, and new owners will need to fill out a form on Walther's website in order to request a plate that matches their optic. I requested my plate on a Friday, and it took about 5 business days to land in my mailbox. The optic that I am using is the Swampfox Justice, which is an RMR footprint, and the accessory Ironsides shield that goes over the optic. I picked both of these up from Brownells.
Mounting the optic is relatively simple. In a nutshell, you remove the plastic cover plate on the slide, screw the mounting plate to the slide and then screw the optic onto the mounting plate. There are some points to note when doing this, though:
1) Always make sure your weapon is unloaded when working on it! Safety first.
2) Check to see if the plate needs to be mounted to the slide first before screwing the optic onto it. For some footprints, like the RMR footprint for example, the optic screws do not line up with the threaded section in the slide. Once the optic is screwed onto the plate there is no access to the screws securing the plate to the slide. It's easy to get ahead of yourself and mount the optic to the plate, only to have to remove it again because there's no way to mount the plate to the slide!
3) Verify which screws you need to use to mount the plate to the slide, and the optic to the plate. These may differ depending on which optic you're running. I used the factory Walther screws to secure the plate to the slide, and the screws provided with the optic to mount the optic to the plate.
4) Have some blue threadlocker/Loctite on hand to help secure the mounting screws. These parts are riding on the slide as they violently cycle, and screws could easily come loose without the added assistance of threadlocker.
5) On a related note, I would recommend against using red or high-temp threadlocker. This stuff is notably stronger than the regular blue threadlocker, and needs to be heated to be removed and can be a real pain to undo. This is particularly important if your optic needs to be unmounted to replace the battery!
6) DO NOT crank down as hard as you can on the mounting screws! Doing so can damage them or strip them out, at the very least make your life very difficult if you need to remove the optic. Always follow recommended torque specs for your optic. I torqued the screws holding the plate to the slide to the 18 inch-pounds noted in the PDP owner's manual (which you read, right?) and torqued the screws holding the optic to the plate to 15 inch-pounds.
7) It can be helpful to make some small witness marks on the screws with a paint marker or something, so that you have an easy at-a-glance reference to make sure the screws are still snug.
After mounting and torqueing everything down, don't forget to zero the optic! Take it to a range and zero it according to the manufacturer's instructions. It'll also give you a change to get some trigger time in and practice with the optic. If this is your first pistol mounted optic, it might take some getting used to presenting the gun so that the dot appears in your field of view...this is a great time to practice!
That's all I have for you this time. If you're interested in the PDP or in the Swampfox Justice, you can pick them up at Brownells. Don't forget to check out the PT Youtube channel too! Until next time....stay safe!