I did a test a while back with 358156. I shot bullets powder coated and without gas checks at .38 Spl vel. and at .357 Mag vel. I found accuracy to be equal to bullets that were checked and lubed.
I recently cast a batch of the RCBS 429 240 Sil. bullet and powder coated them without gas checks. These shot terrible, about 8" 50 yd. groups out of a Ruger Super Blackhawk Hunter with a 2X scope. I added gas checks and they are now shooting in the 2 1/2 to 3" range. This is equal to past experience with this bullet checked and lubed.
So I have one bullet that works well powder coated without the gas check and one that doesn't.
Your opinions and speculations are welcome.
