My brother gave me a brand new G21sf for my birthday, and I loaded up some 225gr hardcast truncated cone bullets and some 255gr hardcast lswc bullets. 225gr loads ranged from 5.5gr to 5.8gr of Unique. 255gr loads ranged from 4.9 to 5.2 gr of Unique. I ran 100 rounds of 230gr ball ammo (American Eagle and Sellier & Bellot) thru the 21 to begin with, and the accuracy was so-so. I settled on 5.7gr of Unique as the best load for the 225gr bullets. Accuracy was much better with this load than with the ball ammo. The optimum load accuracy wise for the 255gr bullets was 5.0gr of Unique. These were significantly more accurate than anything else I put thru the gun. I believe the velocity is between 750 and 775 fps based on the reloading info I researched. I am loading these Double Tap 255gr lswc 21 bh bullets in both 45acp and 45gap for my 21sf and 37 respectively. They are consistently way more accurate than any jacketed bullet I have put thru either. POA is closer to POI, and the groups are much much tighter. The Double Tap bullets are .452 and the typical jacketed bullet is .451 - could this be the reason for the increased accuracy with the lead bullets: a tighter fit in the barrel? I am using a stock Glock barrel in both the 37 and the 21sf. I get zero leading with the 255gr and the 225gr lead bullets. I assume the tighter groups are due to one or more of the following possibilities: -a better fit in the barrel/rifling -a more stable longer bullet -the twist rate in the these two Glocks is being better suited to heavier bullets The standard propaganda on line is that lead bullets don't work as well with Glock rifling, they barrels lead badly, and the 45acp is optimized at 230gr while the 45gap is somewhere around 185 to 200 at best. I need to try some light bullets in both guns to see how they compare to the heavy ones. The heavy ones are certainly beating the mid-range and recommended weight bullets in my guns. Has anyone else experienced similar results to what I am experiencing. Thanks Tombo 65 Wanna kill these ads? We can help!