Bullet weight really doesn't matter very much as long as it consistently and reliably penetrates between 12 and 16 inches, in my opinion. The newer medium weight bullets are demonstrating pretty good terminal penetration performance. Heck, if a 135gr JHP in .45 ACP penetrated between 12 and 16 inches, I wouldn't have a problem with it unless it fragmented or exhibited runaway expansion.
I don't think there's any one suitable general-purpose JHP cartridge for the G30. Remington GS 185gr +P is probably the closest, but it too, will suffer expansion failures and overpenetrate from time to time. If I carried a G30, it would probably be the load I'd choose for it.
A 200gr Speer Gold Dot bullet loaded by either ProLoad or Georgia Arms is a great summer load, and a 185gr +P Speer Gold Dot loaded by either ProLoad or Georgia Arms would make a good winter load. However, I haven't found a load yet for the G30 that won't suffer intermittent expansion failures and overpenetration when heavy clothing is encountered.
Now a G27 loaded with Remington GS 165gr is a superb combination. Terminal performance averages about 12-14 inches in both bare and denim covered gelatin. While there are die-hard .45 ACP fans out there, a G27 loaded with 165gr bullets is a much better choice than a G30, in my humble opinion.
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/s/ Shawn Dodson
Firearms Tactical Institute
http://www.firearmstactical.com