HBG Loyal Thunder quick questions. Dont think I've ever really played the Heavy Bow Gun (main Hammer, IG, and Bow) but wanted to give it a try after stumbling upon some jewels for it, and went with the ever popular Loyal Thunder.

1. Should I only be using Spread 3 Ammo? Is there a reason to even bring other types? 

2. I'm having a hard time getting an optimal skill build, maybe due to me having a whole lot less of the Ironwall Jewels than I thought. I have max critical eye, WE, and a few other of the important ones. I made 2 builds with the only difference being the Helm and the jewels. One has level 5 Guard, level 2 CB (with a 3rd in a mantle), level 2 release, 1 Spread and 1 tool specialist. The other only has level 4 guard, 1 CB with 2nd in mantle, level 3 release, 2 spread shot, and no maintenance. Which is better? I have to use an Uragaan piece for 2 points of Guard. There are really no good armor pieces with the Spread Skill.

Thanks in advance!