Resource Pack Models changed generic item model scale?

I've been making a resource pack for my server, which includes custom models, but I noticed when you hold a item that has models but isn't that model number, it's strangely larger and at an incline when viewed from third person/by another person. Example below.
Here's what I have for the .json of the emerald:
{
"parent": "item/handheld",
"textures": {
"layer0": "item/emerald"
},
"overrides": [
{ "predicate": {"custom_model_data": 5}, "model": "item/greencrystal"},
{ "predicate": {"custom_model_data": 6}, "model": "item/greencylinder"}

]


}

Any help would be appreciated, thanks!