The question of "will shooting releaded lead bullets in my 9mm give me barrel leading problems?" is not easily answered. There are many factors.

1. Yes, it may give you barrel leading if you load to higher velocity, mismatch the bullet and barrel diameters, or use a hot burning powder.

2. No, leading won't be a problem if you shoot hard cast lead bullets, match the barrel and bullet diameters, and don't try for maximum velocities.

3. Plated bullets loaded to around 1,000 fps with Bullsey, WW 231, or similar fast burning powder will eliminate leading.

4. Regular, thorough cleaning with brass bristle brush and bore solvent will minimize leading. Some formulas clean more effectively and prevent leading buildup.

5. Mixing lead and jacketed ammo is no problem. Regular cleaning is a must for best reliability because lead bullets usually foul more than jacketed bullets.

For serious carry, you DO clean and lube after every shooting session, don't you?