Well, I created a custom rendering class for my rocket launcher, But it only renders in 3rd person... Here is my RenderItemRocketLauncher

 

package battleofthebeasts.render;

import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.inventory.GuiContainerCreative;
import net.minecraft.client.gui.inventory.GuiInventory;
import net.minecraft.client.renderer.entity.RenderManager;
import net.minecraft.entity.Entity;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.EnumAction;
import net.minecraft.item.ItemStack;
import net.minecraft.util.ResourceLocation;
import net.minecraftforge.client.IItemRenderer;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.event.entity.player.ArrowLooseEvent;

import org.lwjgl.opengl.GL11;

import battleofthebeasts.models.RocketLauncherModel;


public class RenderRocketLauncher implements IItemRenderer 
{
//public static final ResourceLocation Texture = new ResourceLocation(BattleOfTheBeastsMod.modid, "/textures/entity/RocketLauncher.png");

protected RocketLauncherModel rocketlaunchermodel;



public RenderRocketLauncher()
{
	rocketlaunchermodel = new RocketLauncherModel();
}

// protected ResourceLocation func_110832_a(RocketLauncherModel par1EntitySpiderQueen)
    //{
  //      return Texture;
    //}

   
@Override
public boolean handleRenderType(ItemStack item, ItemRenderType type) 
{
	switch(type)
	{
	case EQUIPPED: return true;
	default: return false;
	}
}

@Override
public boolean shouldUseRenderHelper(ItemRenderType type, ItemStack item, ItemRendererHelper helper) 
{
	return false;
}

  public EnumAction EQUIPPED(ItemStack par1ItemStack)
    {
        return EnumAction.bow;
    }

@Override
public void renderItem(ItemRenderType type, ItemStack item, Object... data) 
{
	switch(type)
	{
	case EQUIPPED:
	{


	        
		GL11.glPushMatrix();

		Minecraft.getMinecraft().renderEngine.func_110577_a(new ResourceLocation("battleofthebeasts", "textures/models/RocketLauncher.png"));			//ResourceLocation Texture = new ResourceLocation(BattleOfTheBeastsMod.modid, "/textures/entity/RocketLauncher.png");




		boolean isFirstPerson = false;

	if(data[1] != null && data[1] instanceof EntityPlayer)	
	{
		if(!((EntityPlayer)data[1] == Minecraft.getMinecraft().renderViewEntity && Minecraft.getMinecraft().gameSettings.thirdPersonView == 0 && !((Minecraft.getMinecraft().currentScreen instanceof GuiInventory || Minecraft.getMinecraft().currentScreen instanceof GuiContainerCreative) && RenderManager.instance.playerViewY == 180.0F)))			
		{
//ThirdPerson
			isFirstPerson = false;
			GL11.glTranslatef(0.4F, 0.5F, 0.08F);
			GL11.glRotatef(-26F, 1.0F, 0.0F, 0.0F);	//X
			GL11.glRotatef(165F, 0.0F, 1.0F, 0.0F); //y
			GL11.glRotatef(140F, 1.0F, 0.0F, 1.0F);   //z
		}
		else
		{
			if(!((EntityPlayer)data[1] == Minecraft.getMinecraft().renderViewEntity && Minecraft.getMinecraft().gameSettings.thirdPersonView == 0 && !((Minecraft.getMinecraft().currentScreen instanceof GuiInventory || Minecraft.getMinecraft().currentScreen instanceof GuiContainerCreative) && RenderManager.instance.playerViewY == 0.0F)))			
//First Person
			isFirstPerson = true;
			GL11.glTranslatef(-0.0F, 0.0F, 0.0F);
			GL11.glRotatef(0F, 1.0F, 0.0F, 0.0F);	//X
			GL11.glRotatef(0F, 0.0F, 1.0F, 0.0F); //y
			GL11.glRotatef(0F, 1.0F, 0.0F, 1.0F);   //z
			rocketlaunchermodel.render((Entity)data[1], 0.0F, 0.0F, 0.0F, 0.0F, 0.0F, 0.7F);
		}
	}	
		else
		{
			GL11.glTranslatef(-0.05F, 0F, -0.0F);
		}

	}
																			//Size
	rocketlaunchermodel.render((Entity)data[1], 0.0F, 0.0F, 0.0F, 0.0F, 0.0F, 0.07F);
	GL11.glPopMatrix();

	default: break;
	}


}
}

Hi.

 

I suspect you need to change your handleRenderType to return true for EQUIPPED_FIRST_PERSON as well as EQUIPPED.  EQUIPPED is 3rd person only.  Likewise your renderItem code.

 

This sample code might help:

 

http://greyminecraftcoder.blogspot.com.au/2013/09/sample-code-for-rendering-items.html

 

https://github.com/TheGreyGhost/ItemRendering/blob/master/src/TestItemRendering/items/ItemLampshadeRenderer.java