Good to see you back. Unfortunately Everyone doesn't know it's back yet. Casting isn't hard. It is very rewarding. For the last few years I have been too busy to even set my casting stuff back up. Give Mountain Molds a buzz. Here is a link: https://mountainmolds.com/
As far as shooting bullets without a gas check on low end loads it works OK. I tried to push some .44 bullets that was a gas check design fast and it didn't work well. Individual guns vary and I have heard of some guns shooting pretty stiff loads without a gas check OK. One thing with having a mold cut is you can get a two cavity with one gas check and the other plain base. Lyman has a really good book to get you started.

It is interesting that the 335gr works well for you. We have tried it in numerous guns and it was always mediocre. From the 4 5/8" guns I can drive the 360gr Oregon trail 1250fps using the 300MP data with no problems. Once again different guns have different likes.

What part of Colorado is your shot located?

"A quiet hit in the right place is better than a loud miss in the wrong place followed by 10 more shots on the run"

I was a handgun hunter, when handgun wasn't cool.....