Crimson Trace LG-401 Lasergrip for 1911 Full-size-Red

Dear Sir!

Based on the product specifications and compatibility details for the Crimson Trace LG-401 Lasergrip (SKU: CRI01-1200), it is designed to fit full-size 1911 frames, including those from Springfield Armory, as long as the grip screws are spaced 3-1/16" apart (which is standard for most full-size 1911s like your Springfield 1911 .45 Marine Corps Operator).

However, the LG-401 is not compatible with ambidextrous (ambi) thumb safeties out of the box. The Springfield 1911 Marine Corps Operator model does come equipped with an extended ambidextrous thumb safety (one lever on each side of the frame for left- and right-handed use). The protruding right-side safety lever interferes with the laser grip's installation and fit.

Options to Make It Work:

Shortened Ambi Safety Replacement: Crimson Trace recommends (and sells) shortened ambidextrous safeties from Wilson Combat (available in black or stainless steel for around $60). These are specifically designed to be compatible with the LG-401. Installation of the safety and the laser grips requires gunsmithing, as it involves modifying the frame fit and ensuring proper alignment.

Alternative Laser Grips: If you prefer not to modify the safety, consider Crimson Trace's Master Series models like the LG-901 (rosewood) or LG-904G (G10 black/grey), which are explicitly designed to be fully compatible with ambidextrous safeties without any modifications needed.
Installation Notes: The LG-401 itself installs by replacing the factory grips (user-installable with basic tools), but the ambi safety issue would need professional help. Always verify the exact screw spacing on your pistol before purchasing.