My gun's barrel is NOT threaded to take a choke. So, I'm wondering if it's possible to tighten up my pattern by ammo selection. To test the gun I basically just bought the cheapest I could find online, and I'm pretty clueless. This is what I bought: ... and this is what it's loaded with: The "Shotgun 101" library link pinned above suggests "heavier shot moving slower" for a tighter pattern. Given that some .410 is going for over $2 per shell, I really don't care to do a "scattershot" approach. Pun intended. Which shot and what can I expect to achieve? Or do I need to take the gun directly to my gunsmith and see if he can thread it for a choke? Advice??