Clark Custom Guns Colt Government Model Mk IV/Series 70 Heavy Slide .45 ACP with Bo-Mar Tuner Rib, 5" Barrel (1972)
This Clark Custom Guns Heavy Slide conversion on a Colt Government Model Mk IV/Series 70 is a purpose-built bullseye/target 1911 from the early Series 70 era. It features the Bo-Mar full-length Tuner rib with a micrometer-adjustable rear sight and tall integral front blade, a stippled frontstrap, and a replacement arched stippled mainspring housing. The right side of the slide carries the "Clark HEAVY SLIDE KEITHVILLE, LA 71047" script, and the Bo-Mar rib is marked "BO-MAR PAT" and "TUNER." Manufactured in 1972, with early Series 70 70G-prefix context.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: Minor, superficial scratches and blemishes are present. The frontstrap is stippled. The right side of the slide is engraved with "Clark Heavy Slide Keithville, LA 71047."
What’s Included
- 1x 7-round 1911 single-stack steel magazine with witness holes
This pistol is a Clark Custom Guns bullseye/target conversion identified by the Heavy Slide profile and the slide script "Clark HEAVY SLIDE KEITHVILLE, LA 71047." It retains the Government-size 5" configuration with an external barrel bushing and spring plug, set up for precise sighting and stable recoil characteristics.
The Bo-Mar full-length Tuner rib adds a micrometer-adjustable rear sight and a tall front blade integral to the rib. The rib itself is marked "BO-MAR PAT" and "TUNER," consistent with period target builds and Clark's well-known competition conversions.
Clark modifications include a stippled frontstrap for improved purchase and a skeletonized target trigger. The mainspring housing has been replaced with an arched, stippled unit. A spur hammer, thumb safety, and grip safety round out the classic 1911 control layout.
This is a blued steel 1911 in .45 ACP with a 5" barrel and 7+1 capacity. Built in the United States during the 1970s, it reflects early Series 70 production context (70G serial prefix) and showcases Clark's Heavy Slide approach paired with premium target sights.