The Strike Industries Multi-Function QD End Plate and Anti-Rotation Castle Nut, Red (brand part no. SI-AR-UL-MFEP-ACN-RED) gives AR-15 builders a more serviceable alternative to the traditional peened castle nut and end plate system. Strike Industries designed this set to update a system that, while it retains a receiver extension well, is not friendly to rebuilding once the castle nut has been peened in place. A set screw secures the Anti-Rotation Castle Nut instead of peening, so the buffer tube can be removed and reinstalled repeatedly as a build is upgraded. The reversible End Plate itself adds real utility beyond retention, offering three separate sling mounting options in one part.

Key Specifications

• Uses a set screw to secure the castle nut instead of peening, allowing the buffer tube to be removed and reinstalled.
• The End Plate is fully reversible, working the same regardless of which side faces out.
• Includes a built-in anti-rotate QD socket for quick-attach sling mounting.
• Also offers a traditional sling loop as a second mounting option on the same plate.
• Adds a hook-style attachment loop as a third sling mounting method for maximum flexibility.
• Finished in red for a distinct, visible accent on the receiver extension.

Frequently Asked Questions

Why use a set screw instead of peening? A peened castle nut is difficult to remove without damage; the set screw lets you disassemble and rebuild the buffer tube setup repeatedly.

How many sling mounting options does this offer? Three: a traditional sling loop, a hook-style attachment loop, and an anti-rotate QD socket.

Buy the Strike Industries Multi-Function End Plate and Castle Nut

Upgrade your AR-15 buffer tube retention with a rebuildable, multi-option Strike Industries end plate and castle nut set. Order it from our Strike Industries lineup of rifle stocks and our Lubbock, Texas team will get it shipped out quickly.