38 Spl and 9 mm round nose seating issue?

I found the swaged RN bullets in 38 shot very well IN FACTORY AMMO. The best performance was with WW police loads and l used Remington for the short line. I almost by accident used some 9mm factory RN 115 in a match pistol and was very surprised at the good 50 yd groups.

Now that said, I have not had good luck/consistency reloading RN in either caliber. Using Magtec 38, l would get a few good 50 yard shots then a wild 5 ring flyers That is not me. 9mm reloading with RN was a bust even though l matched the velocity.

I suspect the issue is bullet eccentricity in seating. I do have the Masaki seating stems but even they may not seat a RN straight whereas they do for shouldered bullets or conicals. Maybe a proper profile seater is needed here?

What say you?

Photo Escape's expanders helped for me.
If they are not available for your press maybe Lyman "M" expander die might work.

Bruce,
You are thinking in right direction.  At one point I experimented with loading bullets with different profiles for my 38 SPL ammo.  I used my HTC PTUs with proper size expanders, and that addressed concentricity of bullets seating.  However, I felt that seating needed improvement, especially with SWC bullets.  I machined seating stems (and adjusted profile on OEM one) for Redding die.  Resulting ammo performed quite good while tested out of three different S&W M14s, and held 10 ring at 50Y 9/10 shots out of RR.  Here is picture for the reference.  AP

Bruce, I've seen a seating die a guy made. He greased a bullet, then used a hot glue gun and put some glue in his seating stem and carefully shoved his bullet in it. He made good loads with it. 
 I cast my own and use the Lee 158 RN TL mould, I can use APs seating stem for SWC and it catches the top tumble lube rib seating them perfectly. Jason Gregoire uses that bullet also, I used 2.9 of BE and he said to try 2.8 of Tite Group. TG does have a different impulse which is nice. If I had to use a bullet without a rib or shoulder, I'd use that hot glue method and have a custom stem just for that bullet. What's nice about it is it doesn't take much to take it off the seating stem.
 Stan

I have had good luck with that Lee casting; it's 150 gr for that 1R  or single radius bullet.  I get the occasional flyer, but nothing as bad as 2R designs though. It, like a swc, has a long straight body that accommodates straight seating. Going to look at what I have for seaters and get with Alex at some point.

I thought those bullets were cast with a shoulder.
I got shoulder seating stems from Unique-Tek.