The manufacturing difficulties with welded sheet metal receivers significantly impacted AK-47 production in several ways:

1. Quality Control Issues: The welding process for sheet metal receivers required precise techniques to ensure structural integrity. Early production faced challenges with weld quality, leading to issues such as weak joints and misalignment. This necessitated additional quality control measures and rework, slowing down production rates.

2. Production Delays: The complexity of welding operations compared to simpler machining processes meant that production lines were often delayed. Factories had to adapt to the new welding techniques, which could lead to bottlenecks in the assembly process.

3. Material Limitations: The choice of materials for the sheet metal also posed challenges. The steel used had to be of a specific grade to withstand the stresses of firing and handling. Variability in material quality could lead to inconsistent performance, further complicating production.

4. Design Modifications: To address the difficulties encountered, engineers sometimes had to modify the design of the receiver or the manufacturing process. These changes could lead to variations in the final product, affecting interchangeability and standardization across different production runs.

5. Impact on Military Readiness: For the Soviet military, any delays or issues in AK-47 production could affect troop readiness. The AK-47 was a critical component of Soviet military strategy, and production difficulties could hinder the supply of weapons to troops.

6. Long-term Solutions: Over time, the Soviet Union invested in improving welding techniques and training for workers, which helped to stabilize production. The experience gained from these challenges ultimately contributed to the refinement of manufacturing processes for future firearms.

In summary, the difficulties with welded sheet metal receivers initially posed significant challenges to AK-47 production, affecting quality, efficiency, and military readiness. However, these challenges also led to improvements in manufacturing practices over time.