Hello, GP100man. Those are some nice looking bullets, and a nicer looking mould! Don't touch that mould! It probably is an early one, with collector value. I have many of the very early Ideal moulds from .22 up and alot have no vent lines & cast just fine. Some have only one or two running from a lube groove or band up at an angle to edge of block. A few even have grooves cut in underside of sprue plate..running out from sprue hole! When I was shooting IHMSA, I used the Lyman 358429 around 170gr. in a S&W mod. 27. Recently, I tried an Ideal 358430 at 200gr.! Even with light charges, that one kicks! Best of luck.