diff --git a/Tactical/LOS.cpp b/Tactical/LOS.cpp
index 3919efd9..de01a0db 100644
--- a/Tactical/LOS.cpp
+++ b/Tactical/LOS.cpp
@@ -5323,7 +5323,7 @@ INT32	CheckForCollision( FLOAT dX, FLOAT dY, FLOAT dZ, FLOAT dDeltaX, FLOAT dDel
 	FLOAT						dTargetZMax;
 	BOOLEAN					fIntended;
 
-	INT16						sX, sY, sZ;
+	INT32						sX, sY, sZ;
 
 	FLOAT						dOldZUnits, dZUnits;
 
@@ -5331,9 +5331,9 @@ INT32	CheckForCollision( FLOAT dX, FLOAT dY, FLOAT dZ, FLOAT dDeltaX, FLOAT dDel
 	INT32						iCurrCubesZ;
 
 
-	sX = (INT16)( dX / CELL_X_SIZE );
-	sY = (INT16)( dY / CELL_Y_SIZE );
-	sZ = (INT16)dZ;
+	sX = (INT32)( dX / CELL_X_SIZE );
+	sY = (INT32)( dY / CELL_Y_SIZE );
+	sZ = (INT32)dZ;
 
 	// Check if gridno is in bounds....
 	if ( !GridNoOnVisibleWorldTile( sX + sY * WORLD_COLS ) )
diff --git a/TileEngine/physics.cpp b/TileEngine/physics.cpp
index 3fc0f6df..58908e02 100644
--- a/TileEngine/physics.cpp
+++ b/TileEngine/physics.cpp
@@ -1497,7 +1497,7 @@ vector_3 FindBestForceForTrajectory( INT32 sSrcGridNo, INT32 sGridNo,INT16 sStar
 
 	//calculate force needed
 	{
-		dForce = (float)( 12 * ( sqrt( ( GRAVITY * dRange ) / sin( 2 * dzDegrees ) ) ) );
+		dForce = (float)( 12.0 * ( sqrt( ( GRAVITY * dRange ) / sin( 2.0 * dzDegrees ) ) ) );
 	}
 
 	do
@@ -2139,8 +2139,8 @@ FLOAT CalculateForceFromRange( INT16 sRange, FLOAT dDegrees )
 
 	// OK, use a fake gridno, find the new gridno based on range, use height of merc, end height of ground,
 	// 45 degrees
-	sSrcGridNo	= 4408;
-	sDestGridNo = 4408 + ( sRange * WORLD_COLS );
+	sSrcGridNo	= WORLD_COLS/2+WORLD_COLS*WORLD_ROWS/6;
+	sDestGridNo = sSrcGridNo + ( sRange * WORLD_COLS );
 
 	// Use a grenade objecttype
 	CreateItem( HAND_GRENADE, 100, &gTempObject );