Ah, the joys of reloading and encountering specific challenges with load data! It's understandable that finding specific load data for your particular bullet shape can be frustrating, especially when most reloading manuals provide COAL (Cartridge Overall Length) recommendations for flat-nosed bullets. However, here are a few approaches you can take to determine a suitable COAL for your round-nosed or semi-wadcutter bullets.
Consult Bullet Manufacturers: If you know the brand or specific make of your bullet molds, it's worth checking the manufacturer's website or contacting their customer support. They might have load data or recommended COAL specifically for their bullets. They can provide valuable insights based on their testing and expertise.
Load Development and Testing: Since you mentioned these loads will be for paper punching and experimenting, you have some room for load development. Start by selecting a conservative starting load of Trail Boss powder based on the powder manufacturer's recommendations. Gradually work your way up, monitoring pressure signs, and assessing accuracy and performance. Remember to follow safe reloading practices and be cautious when increasing powder charges.
Adjusting COAL: In the absence of specific COAL data, you can start with a COAL recommended for a similar bullet shape, such as a flat-nosed bullet, and adjust it slightly. Increase or decrease the COAL in small increments (e.g., 0.010 inches) while checking for proper chambering, feeding, and accuracy. Be mindful of maintaining adequate bullet seating depth to ensure reliable functioning.
As always, when experimenting with loads, it's important to exercise caution, follow proper reloading procedures, and start with conservative loads. Keep detailed records of your loads, including bullet type, powder charge, COAL, and any notable observations or results. This will help you track your progress and ensure safety throughout the process.
Happy reloading and may your future loads be accurate and satisfying!