A heat shield panel (300; 400; 500; 600; 700; 800) for use in a gas turbine engine combustor, comprising: a hot side (302; 402; 502; 602; 702; 802); a cold side (304; 404; 504) spaced from the hot side (302; 402; 502; 602; 702; 802); a rail member (308; 408; 508; 608; 708; 808) disposed on the cold side (304; 404; 504) proximate an outer perimeter of the heat shield panel (300; 400; 500; 600; 700; 800), the rail member (308; 408; 508; 608; 708; 808) having an outer wall (310; 410; 510; 610; 710; 810) and an inner wall (312; 412; 512; 612; 712; 812); and an orifice (420; 520; 620; 720; 820) extending through the rail member (308; 408; 508; 608; 708; 808), from the inner wall (312; 412; 512; 612; 712; 812) to the outer wall (310; 410; 510; 610; 710; 810), the orifice (420; 520; 620; 720; 820) having an entrance portion (328; 428; 528; 628; 728; 828) having an entrance opening positioned on the inner wall (312; 412; 512; 612; 712; 812) and extending at least to an intermediate portion (332; 432; 532; 632; 732; 832) of the rail member (308; 408; 508; 608; 708; 808), and an exit portion (330; 430; 530; 630; 730; 830) having an exit opening (326; 526) positioned on the outer wall (310; 410; 510; 610; 710; 810) and extending at least to the intermediate portion (332; 432; 532; 632; 732; 832) of the rail member(308; 408; 508; 608; 708; 808); characterised in that the entrance portion (328; 428; 528; 628; 728; 828) of the orifice (420; 520; 620; 720; 820) is angled relative to the exit portion (330; 430; 530; 630; 730; 830) of the orifice (420; 520; 620; 720; 820). a hot side (302; 402; 502; 602; 702; 802); a cold side (304; 404; 504) spaced from the hot side (302; 402; 502; 602; 702; 802); a rail member (308; 408; 508; 608; 708; 808) disposed on the cold side (304; 404; 504) proximate an outer perimeter of the heat shield panel (300; 400; 500; 600; 700; 800), the rail member (308; 408; 508; 608; 708; 808) having an outer wall (310; 410; 510; 610; 710; 810) and an inner wall (312; 412; 512; 612; 712; 812); and an orifice (420; 520; 620; 720; 820) extending through the rail member (308; 408; 508; 608; 708; 808), from the inner wall (312; 412; 512; 612; 712; 812) to the outer wall (310; 410; 510; 610; 710; 810), the orifice (420; 520; 620; 720; 820) having an entrance portion (328; 428; 528; 628; 728; 828) having an entrance opening positioned on the inner wall (312; 412; 512; 612; 712; 812) and extending at least to an intermediate portion (332; 432; 532; 632; 732; 832) of the rail member (308; 408; 508; 608; 708; 808), and an exit portion (330; 430; 530; 630; 730; 830) having an exit opening (326; 526) positioned on the outer wall (310; 410; 510; 610; 710; 810) and extending at least to the intermediate portion (332; 432; 532; 632; 732; 832) of the rail member(308; 408; 508; 608; 708; 808); characterised in that the entrance portion (328; 428; 528; 628; 728; 828) of the orifice (420; 520; 620; 720; 820) is angled relative to the exit portion (330; 430; 530; 630; 730; 830) of the orifice (420; 520; 620; 720; 820). an entrance portion (328; 428; 528; 628; 728; 828) having an entrance opening positioned on the inner wall (312; 412; 512; 612; 712; 812) and extending at least to an intermediate portion (332; 432; 532; 632; 732; 832) of the rail member (308; 408; 508; 608; 708; 808), and an exit portion (330; 430; 530; 630; 730; 830) having an exit opening (326; 526) positioned on the outer wall (310; 410; 510; 610; 710; 810) and extending at least to the intermediate portion (332; 432; 532; 632; 732; 832) of the rail member(308; 408; 508; 608; 708; 808); characterised in that the entrance portion (328; 428; 528; 628; 728; 828) of the orifice (420; 520; 620; 720; 820) is angled relative to the exit portion (330; 430; 530; 630; 730; 830) of the orifice (420; 520; 620; 720; 820).