I am not a bullet maker but have made a few Blaaistic Tips
. Looks like you have done a very nice job with your new bullets. Based on what I see your Meplats look like on the sierra's...I think you will be happy with the ballistic tip results.
As you well know, this is somewhat of a labor intensive project as compared to buying a bullet and just shooting it. Rolling your own does have its advantages though.
I have the Meplat trimmer and bullet pointing dies. I certainly think that doing these things help a little. We have been making ballistic tips for a little while now. We make ballictic tips for a bullet maker on this site. One of the tips we are making is for the 300smk. We designed it for a little better BC but more importantly, we wanted a long range bullet that would open up better at lower velocity's.
We have not been able to test the 300smks but the results in 30caliber bullets has been very good. We just did a run of 1,500 tips for 30 caliber and 338's. Hope to be doing some testing on the 300 smk's soon.
Now having said all this, Bergers new Hybrid seems to be King of the mountain. I am still waiting for Bergers new design for my 338LAI. Until then, I have something to fool around with.
Good luck with your project. Let us know how it works out.