I know that the registration could be the problem, but since there is actually no metadata value saved how can i register it properly? Like a normal metadata block (so using a normal ItemBlock class and registering every variant with a different name?)

Ok, so i've now this

block.setUnlocalizedName(name);
	GameRegistry.registerBlock(block, name);
	ModelBakery.addVariantName(Item.getItemFromBlock(coal_block), 
			BL.MODID + ":" + "coal_block_0", 
			BL.MODID + ":" + "coal_block_1",
			BL.MODID + ":" + "coal_block_2",
			BL.MODID + ":" + "coal_block_3",
			BL.MODID + ":" + "coal_block_4",
			BL.MODID + ":" + "coal_block_5",
			BL.MODID + ":" + "coal_block_6",
			BL.MODID + ":" + "coal_block_7",
			BL.MODID + ":" + "coal_block_8",
			BL.MODID + ":" + "coal_block_9",
			BL.MODID + ":" + "coal_block_10");
	for(int i = 0; i < 11; i++)
		renderItem.getItemModelMesher().register(Item.getItemFromBlock(block), i, new ModelResourceLocation(BL.MODID + ":" + name + "_" + i, "inventory"));

The model file are pretty the same as before (only the block high on each value is changed)

So now if i place a block down it place the last block model registered (the corresponding to the damage value of 10)

 

EDIT: printing this in the getActualState always return 10

System.out.println(state.getValue(DAMAGE));

 

so basically the damage value is never change, even doing this

newState = state.withProperty(DAMAGE, Integer.valueOf(progress.getPartialBlockDamage()));

Alright, so now my block is registered as a normal block, and as i said in the previous edit i print the damage value when breaking the block but is always 10, event if i force it to 0

Don't worry man, at least you tried to solve this problem Thanks for all your support Hope to find out a way to make this work

Ok, quick discover. If i comment everything in my getActualState method and only do this

state.withProperty(DAMAGE, Integer.valueOf(3));

 

it return the block model for the damage value of 3, wich is correct. So i think that the problem could be in this method

@Override
@SideOnly(Side.CLIENT)
public IBlockState getActualState(IBlockState state, IBlockAccess worldIn, BlockPos pos)
{
	IBlockState newState = null;

	RenderGlobal render = Minecraft.getMinecraft().renderGlobal;

	DestroyBlockProgress progress;

	if(damage != null)
	{
		Map mp;
		try {
			mp = (Map)damage.get(render);
			Iterator it = mp.entrySet().iterator();
			while (it.hasNext()) {
				Map.Entry pair = (Map.Entry)it.next();
				progress = (DestroyBlockProgress) pair.getValue();

				if(progress.getPosition().equals(pos))
				{
					newState =  state.withProperty(DAMAGE, Integer.valueOf(progress.getPartialBlockDamage()));
				}
			}
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}
	return newState;
}

Woops Ok, changed to this

/**
 * Get the actual Block state of this Block at the given position. This applies properties not visible in the
 * metadata, such as fence connections.
 */
@Override
@SideOnly(Side.CLIENT)
public IBlockState getActualState(IBlockState state, IBlockAccess worldIn, BlockPos pos)
{
	RenderGlobal render = Minecraft.getMinecraft().renderGlobal;

	DestroyBlockProgress progress;

	if(damage != null)
	{
		Map mp;
		try {
			mp = (Map)damage.get(render);
			Iterator it = mp.entrySet().iterator();
			while (it.hasNext()) {
				Map.Entry pair = (Map.Entry)it.next();
				progress = (DestroyBlockProgress) pair.getValue();

				if(progress.getPosition().equals(pos))
				{
					return state.withProperty(DAMAGE, Integer.valueOf(progress.getPartialBlockDamage()));
				}
			}
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}
	return state;
}