"was a conversion barrel, or upper conversion? (I know 20 and 21 have the same frames, but I thought uppers on 20 are stronger for some reason."
*****
The Caliber Conversion Consists Of:
- KKM .45 ACP : 10 mm Conversion Barrel
- LWD Stainless Steel Guide Rod
- ISM 22 lb. Spring
- 10 MM Magazines
That's it!
With regard to the slides, the stock G20 slide is heavier, but the extra metal is nowhere near the firing chamber, so it's there to provide a little extra mass. I compensated for this by increasing the spring from the stock 17 lbs., to 22 lbs.
The KKM Conversion Barrel combines a 10 mm bore and fully supported firing chamber, designed to accommodate the slide's .45 ACP breach face.
While I do respect the OEM's design tolerances, you have to remember that with all the possible ammo choices, especially in 10 mm, there is a "window" of safe operating specifications, to pull this off.
The conversion has over 1000 rounds on it, and I'm pleased with it! It came in about 1/2 the cost of a new G20, all costs considered. This is fine for a caliber I don't shoot too often!
I've been shooting the Double Tap 135 grain Noslers exclusively, and do those little gems scream!
--Ray