Sig Sauer P226 XFive Upgrades
Welcome back to Jim's Armory. This one's a follow-up to Jim's earlier teardown of the Sig Sauer P226 X5, and it picks up right where that video left off. Rather than another full inspection, Jim uses this session to actually fix the issues he flagged last time and drop in a few upgrades - an optic, a rear sight, and a new slide release - to take the X5 from a great gun to what he calls an excellent, functional one.
Getting Started: Optic Plate and Cleanup After confirming the gun is clear, Jim removes the rear sight and factory optic plate, held on by a T10 screw with a small tab that captures it in the front. This exposes the slide's multi-pattern cut: a Sig Pro footprint with additional RMR holes drilled and tapped, meaning the plate will cover Sig Pro, Delta Point Pro, and RMR footprints. It also reveals the extra threaded hole and indexing divots Jim pointed out in the earlier video - a cutout that most standard optic plates simply won't cover.
Jim considered the aftermarket plates that integrate a rear sight, but wasn't happy with their sight quality, height, or price, so he opts for his own solution instead. Before mounting anything, he cleans the plate and screw holes with alcohol.
Pro-Tip: Don't trust oil residue left in threaded holes - twist up a piece of paper towel and work it into the hole to clean out any oil before applying Loctite.
Mounting the Optic Plate and Holosun The plate Jim installs isn't there just to add threaded holes - it lines up with the existing RMR holes and includes a small filler at the front to eliminate the gap that would otherwise be left, plus indexing posts front and bottom that mate to the slide's dovetail slot. Dry-fitting confirms a clean, tight fit with no added height.
Sig's screw threads are 6-40 rather than the 6-32 pattern Jim had on hand, so he swaps to the correct hardware. After degreasing the screws, he applies blue Loctite 242 - noting the factory dab of Loctite on the original hardware isn't enough on its own - then torques the optic plate screws to 15 inch-pounds using a Fix It Sticks torque driver. With the plate secured, he seats the Holosun RONIN HS507COMP, the optic he considers the best currently available for competition use thanks to its large window and blacked-out housing (no red logo, with a small dragon design on the opposite side). Jim lets the Loctite cure a full 24 hours before shooting.
Closing the Cosmetic Gap: Rear Sight Install With the optic in place, the extra threaded hole and indexing divots on the slide are now exposed and, in Jim's view, ugly if left uncovered. His fix is a suppressor-height rear sight from Sig that includes its own screw and a two-dot texture similar to the factory sight. He installs it with a 2.5mm Allen key, again skipping the factory Loctite in favor of his own, and torques it to the same 15 inch-pounds spec.
Front Sight Swap for Co-Witness To get proper co-witness with the optic, Jim moves to the front sight, which he purchased as a matching suppressor-height set alongside the rear sight - Sig only offers this style in suppressor height. Using a sight pusher (an inexpensive knockoff of a popular name-brand tool that Jim says has worked well for him), he aligns the front sight guides, oils the dovetail to help it slide, and pushes the factory sight off.
Pro-Tip: Don't worry about which direction a sight goes back in - any relief cut on the corners is just there to ease installation, not because the dovetail itself is different width on one side.
Jim reinstalls the new front sight, adjusting height in small increments and checking co-witness against the optic as he goes, until he settles on a partial lower co-witness that lines up correctly.
Slide Release Upgrade The last fix addresses the factory slide release, which Jim finds too small to reach without breaking his grip. Rather than bending the factory piece, he installs an aftermarket slide release from Sig Guy, a resource Jim recommends for Sig-specific tools, parts, and information.
The factory piece rides on the same pin as the trigger, similar to a striker-fired gun's takedown - a slight twist relieves spring tension, letting the part pull free. Jim is careful not to lose the small spring underneath during removal and reinstallation. The new slide release drops in using the same pin and spring, requiring a bit of patience and twisting to seat the flattened section against the spring correctly.
With the new part installed, Jim demonstrates that he can now reach the slide release without altering his grip at all - whether locking the slide back or releasing it after a magazine change.
Final Thoughts Between the properly filled optic plate, the suppressor-height sight set for co-witness, and the reach-friendly slide release, Jim considers these changes enough to turn an already strong pistol into what he calls a truly excellent, functional gun. He notes he did experiment with the trigger but ultimately returned it to factory settings, finding the finger reach and stock feel already ideal for him.
That wraps up the upgrade path on the X5 - stay tuned for more from Jim's Armory, and subscribe so you don't miss what's next.
