Sharps Nut,
Seems like this thread got sidetracked on your question. The round nose has nothing what so ever to do with accuracy.
I have a 6 cavity Hensley and Gibbs mold that dumps a 158 grain round nose plain base bullet. I have 3 wadcutter molds, a Saeco 132gr swc and a 10 cavity 160 SWC, plus several others.
Out of all the bullets in that weight range, the 158 grain round nose bullet is the most accurate in my handguns. I have used the RN in my Marlin 357 rifles with good accuracy. For plinking, stick with your RN mold, if it is accurate in your guns. The 158 grain bullets is good for accuracy out to 100 yards when shooting Clay Birds on the bank.
The SWC would probably be best for any type of hunting purposes. I have a 180 grain Saeco plain base flat nosed bullet that will hit any chicken out to 200 meters.
The question of gas checks was asked in your thread, here. In my Marlin 357 rifle, I use the 180 grain plain base to reach 300 meter pigs (steel targets). the bullet feeds through the action just fine.
However, I also, use the RCBS 200 grain rifle bullet with a gas check. If the mold didn't have the gas check shank, I wouldn't gas check that bullet. I have never tried it without the gas check. I won't tell how far I can shoot with that bullet.
The RCBS bullet is too long to feed through the action on the Marlin, but it is one good shooter.
Harold Clark