Since I was one of the people who mentioned the 9x25 in your other post, I feel compelled to try and help out here.
I think you got some good info on loading data etc... You do have to form your own brass from 10mm cases but it is a single pass through the 9x25 sizing die.
Since you are talking about a Glock 20, it will only take a barrel to convert it. Jarvis is/was making G20 barrels in 9x25.
Tamera,
The 9x25 does hold more powder than the .38 super/9x23 since the 10mm is larger and they are both the same length. This misconception comes from an old article in American Handgunner where Robbie Leatham explains his switch from the 9x25 back to a smaller diameter cartridge, the 9x23. The 9x25 was causing shooters elbow joint problems because the comped guns had a very sharp straight back recoil and a severe concussion given off by the powder coming out of the comp. Leatham said in the article that he compared the case volume of the two and they were very similar so he decided to go to the 9x23 because if they burn close to the same amount of powder, they must make the comp work the same (very scientific) and he could get two more rounds in the gun over the 9x25.
I think there was other factors that also contributed to his change. About the time he stared shooting the 9x25 he was about past his "time in the limelight" as far as IPSC shooting. Don't get me wrong, Robbie is still an awesome shooter but there were lots of young guns coming up throught the ranks who were pushing him hard so if he made any mistakes, he was pushed back in the standings. At this time he was also having serious problems with his pistol in 9x25. He lost some very big matches because he was always having problems with his weapon. Other Springfield Armory shooters using the exact same weapon were not having problems, he was just having a bad time. I really think he was done with the 9x25 as used the "almost the same powder capacity and 2 extra rounds as his reasons to change."
