The nuclear option ....
Nightcrawler: there's no question that
some factory 10mm Auto loads are really watered-down 40-wannabes (or "FBI-Lite" loads).
However, others offer 10mm ammo loaded at or near its full-strength levels - what I call "original theory" 10mm.
Winchester's 10mm/175gn STHP is one such load. As mentioned, CorBon's stuff is another. ProLoad, Georgia Arms, and Texas Ammo also offer pretty hot stuff.
In TA's case they sell 4 hot 10mm loads:
135gn Nosler HP @ 1450fps/630ft-lbs;
165gn Sierra HP @ 1350fps/668ft-lbs;
200gn Hornady XTP/HP @ 1250fps/694ft-lbs;
200gn Hornady FMJ-FP @ 1250fps/694ft-lbs.
Note that the 200gn loads
exceed the original Norma specs. When I placed my first order for the TA 10mm/200gn loads, the guy that runs it told my dealer he wanted to market 10mm ammo "loaded to its full potential."
Just what the 10mm's "full potential" really is, is probably up to reloaders. Over on GT's 10Ring, a frequent contributor and experienced handloader named MCNETT has experimented
extensively with
nuclear level 10mm loads, shooting these thru his Glock 20 and 29 without adverse effect, apparently. His 10mm loads are
WAY past original-theory levels, which says a lot about just how far you can safely push this cartridge. These loads include a Rainier
220gn bullet. (MCNETT has published his 10mm data and detailed comments often enough that you might want to do a Search under his name on the 10Ring and see what I'm talking about).
The Glock 20's stock barrel is 4.6", but if you get the 6" factory "hunting" barrel, or an aftermarket barrel from KKM or Fed. Arms of the same length, you can really pump-up the ft-lbs on these upper-end 10mm loads.
It's true that the Glock 20's (or 29's) grip isn't for everyone. You ought to try shooting it some, if possible, before writing it off.
Also, realize that the 10mm Glocks give you 3-guns-in-1 because of their amenability to barrel-swapping, using aftermarket barrels in .357 Sig or .40S&W from, again, KKM or F. A.
HTH.
