For the folks at home, Taylor Freelance is what you're using, correct?
HK has long been THE WAY for commercial, duty-grade .45ACP. Honorable mention maybe goes to the M&P once upon a time. They are the only ones to have consistently crack the code. Extraction issues alone on the G21 is too much. I like the HK45's over the USP. The modern light rail, iron sight options, and holster selection offsets the mere +2 the USP gives. And not to stir the pot, we used to see some USP's choke (FTF) from time to time if: well-used, dry, and running weak ammo (like win white box). No often, but it was a thing....45's used to always be the first to get sluggish regardless of brand. We don't see much .45 come through the academy these days. 80%+ are now 9mm with 15% 40S&W with the remainder as .45 and other (10mm, .357 Sig)
That being said, so much has changed in recent years. Nobody has really moved the chains on .45ACP like on other platforms. Case in point, I just broke down my 2011 (double stack 1911 for the uninitiated) for its first cleaning after 3000 rounds (4x stops for lube) with the last 1000 rounds being shot in less than 36 hours. Now in 2010, if you'd have told me that I'd be rocking a wide-body 1911 in 9mm with ZERO failures (100% lock backs too) much less after 3k without cleaning, I'd have called you F***ing LIAR!
It's time to be carrying at least 18, 19, 20+ on board in a flush-fit mag boys and girls!
I do like the Taylor Freelance gen3 +3 HK45 extension, however the one I have the most of and use are the HKPRO. Here is a link to my most recent review.
I have posted two prior threads on my continuing search for magazine extensions for the HK45. Here is a link to my last lengthy write up and review of the Taylor Freelance +3 (gen 1) extension, and the HKPARTS +3 extension...
For what it is worth, the HKParts extensions are back in stock.
regarding dms's evaluation of the .45acp cartridge and the lack of innovation regarding it, he is correct. Without a significant push or contract specific to the .45acp, I don't foresee huge innovation in handguns chambered for the round, as 9mm seems to have won the day.
I remain with the .45acp for two reasons, my agency requires it (with very limited exception, ie. very small hand size), and .45acp is simply my preference, it is what I have carried as a duty handgun/caliber for over 25 years. That said, if I were to change, I'd be looking at a 9mm platform, probably P30Ls (cut for an optic), a VP9OR, or a G19 optic ready. I am of the opinion, the G19 is the best handgun Glock has produced. That is my opinion. I'm not a fan of .40 or .357Sig. I dig the 10mm as a hobby gun, but not a duty gun.