before loading for the M9 check to make sure the loaded cartridge will not jam into the rifling. make sure the cartridge fits into the freebore. so far it seems Frontier and Hornady XTP's cannot be loaded very long. according to clubmember Gray Wolf Frontier max is 1.1" through my own testing I found Hornady XTP's max length can be 1.12" for 147gr,1.125" for 124 and 1.127 for 115gr unknown for 90gr. it is possible to size jacketed bullets down using single stage press and a 9mm casing and bullet puller. process may cut into plated bullet. process may also deform bullet. basicly seat a bullet upside down and then use a taper crimp next use bullet puller. issue is with bullets that run .355-.3555 for a majority length of the bullet giving it a tall shoulder and an abrupt taper. Frontier 9mm bullets Hornady 124gr XTP Hornady 124gr FMJ Hornady 147gr FMJ Hornady 147gr XTP recently read KKM uses short throats in theyre barrels and that its good for accuracy. will admit my Steyr M9 is capable of some great accuracy out to 50 yards as long as shooter does his part. if you want to load long take carefull selection in bullet profile. so far I have used Winchester 115gr FMJ hollow base Hornady 115gr FMJ closed base Hornady 124gr FMJ close base Hornady 147gr FMJBT closed base Remington 124gr FMJ exposed base Remington 124gr JHP Remington 124gr GSHP Remington 147gr JHP Remington 147gr GSHP have tried them all loaded to 1.150" I havent tried 1.169" when loading JHP's long make sure the whole cartridge can eject cleanly from the gun. my favorite JHP load with 1.150" didnt work well when it comes to ejecting out of a kel-tec p11 hit the slide ejection port and jams real nicely. so far never a issue with either my M9's or S&W 9VE. if ammo in your M9 is jamming short of battery its good idea to eject the cartridge and check the bullet for rifling contact. it is possible to force a cartridge to load. worse possible things that can happen. boom with possible casehead separation. setback pressure spike or you go to eject a cartridge with bullet stuck on the lands and you pull the bullet spilling the powder( ). then you have to get the bullet out of the barrel good idea to clean the powder up as well. so far havent met any factory ammo that has had any issues with the tight throat.