Mounting themb rests

Securing the thumb rest
If all is well, we suggest you degrease the tapped holes and the screws before appying Loctite 271 or 2760 on the threads to securly mount your thumb rest. Do Not Over Torque the screws when tightening, a snug fit and allowing the Loctite to adequately cure ( 24 hours ) is sufficient.
Now, reassemble and check for proper slide function. If everything is OK, its now time to holster up and retrain your grip. Practice Practice Practice...

Check screws inside dust cover.
Once drilled, tapped and test mounted using our proprietary screws, check one more time to insure the screws are flush with the inside of the dust cover. Trim flush with dust cover if required.

International 3 Hole Pattern Left.

The INTERNATIONAL 3 hole pattern is shown on the left, the holes are 10MM / .397 on center, your gunsmith will drill and tap your firearm as required for perfect placement. We supply three (3) proprietary screws which are metric size 4MM x 07. Our proprietary screws should not require trimming. However you must check to insure they do not protrude into the dust cover well, slight trimming may be required to insure they are flush with the inside of the dust cover.

Domestic 3 Hole Pattern on left.
The DOMESTIC 3 hole pattern is shown on the left, the holes are .375 on center, your gunsmith will drill and tap your firearm as required for perfect placement. We supply three (3) proprietary screws which are size 5-40. Our proprietary screws should not require trimming. However you must check to insure they do not protrude into the dust cover well, slight trimming may be required to insure they are flush with the inside of the dust cover.

Align the relief
The back of the thumb rest has a relief cut to keep the thumb rest away from the slide, this relief should be aligned with the top of the dust cover and should absolutely not come in contact with the slide.
DO NOT PLACE OVER OR COVER YOUR SLIDE LOCK LEVER.

Mark the thumb rests position
With the thumb rest clamped in position, mark the dust cover at the very front of the thumb rest, you can also mark the rear of the thumb rest along the lower curvature. If possible, leave the thumb rest clamped in position for your gunsmith. Once at your gunsmith, test your grip again to insure it is correct and your gunsmith can measure the position accurately.
If possible leave clamped in place for your gunsmith.

Test thumb rest position.
Now place both hands on the frame and to position test your grip, insure the thumb rest is clamped in the proper position, your support hand should be high on the firearm and your thumb pad should be centered along the bore of the barrel. Check to see if your thumb rests on the paddle naturally and comfortably. The bottom of the slide should be halfway along the full lenght of your thumb. If not adjust the thumb rest slightly for proper placement and test your grip aga

Clamping the thumb rest
With your frame on its side, align the thumb rest paddle with the angled mark you made on the dust cover. Align the relief cut on the back of thumb rest with the top of the dust cover. Now clamp in place.

Mark the thumb angle.
Following the pad of your thumb mark the dust cover with a sharpie, this is where the paddle of the thumb rest is to be mounted.

Your thumb should be resting so the bottom of the slide is in the middle of your thumb. Your support hand should naturally cant forward. Now your thumb is in line with the center of the barrels bore.

The thumb muscle is key to your support hand placement. Place your thumb muscle high on the frame as possible to still wrap your fingers under the trigger guard.

Strong Hand Placement.
Your support hand should be as high on the frame as possible with your thumb comfortabily extended straight out along the side of the frame.

Fitting
We recommend a qualified Gunsmith should mark and measure the thumb rest placement based on the correct grip we describe below. The mounting requires the exact placement and precise drilling & tapping of holes in the dust cover of your frame.

Stop - Be Safe
Make sure your chamber is empty, and the magazine has been removed before mounting.
Keep all rounds and loaded magazines away from your work area.