As far as the gas checks are concerned, i don't think they are as necessary as some think especially in the larger cals. Don't get me wrong, if the mould is cut for the GC, use one, I just think that plain base designs work just as well in the larger cals., and saves about 4 cents a bullet over the GC. We push plain base designs to over 2000fps and have no problems with leading, this is based on a well designed bullet with lots of large grooves to hold lube and sized to the right dia.