Welcome home. Pull up a stump and set a spell.

First, is the new barrel from Sig? Is it a new barrel new or new to you barrel? When you say it binds up, when does it bind up?

 

It is a new barrel, and it’s from Sig. The gun itself is used, which kinda had me thinking it was a different caliber originally, and maybe the barrel in it is a conversion barrel. I will check into that. The barrel seems to fall in place but binds front to back once it seats. I have to lightly tap it with my fingers to break it loose.

 

They're the same. SIG has changed the wording and font a few times over the years. Barrel likely needs just a touch of fitting.

 

Not all OEM Barrels are "Drop in", some may require minor fitting, since each part has +/- tolerances, so you can end up with tolerance stacking. Some may be a little loose while others a little too tight... the key to fitting is to remove the excess material from the proper place to not alter things like headspace.

 

I have a ‘81 P220 9mm para, a ‘92 P226 9mm para and a ‘21 MK25 9x19mm. I swapped the barrels between them and they fit each gun. I didn’t test fire them, but I see no reason they wouldn’t be reliable.

 

There can be a very slight difference between properly fit and not fit properly. It can end up putting inappropriate stresses on the mechanism and prevent it from cycling smoothly and properly. Too much space and it will become inaccurate. This is measured in thousandths of an inch. Sometimes a firearm will wear in to settle into correct fitment when this is small enough. in essence, this is based in the skill and judgment of a gunsmith installing the barrel.

If it doesn't smooth out properly, or you start to see galling in the locking areas of the barrel or slide where it mates you should have a gunsmith address this.

There have been multiple names for the 9mm Luger round we know today. 9x19mm... 9mm Parabellum 9mm Luger.. They all refer to the same round invented for the German Luger pistol which first designed in 1901 and first used widely in 1904 with the Navy model Luger. This pistol was manufactured by Ludwig Loewe's subsidiary company DWM (Deutsche Waffen und Munitionsfabriken) whose wire cable address was "Parabellum". Georg Luger had adopted the cartridge as a military power caliber cartridge by increasing the scale of the bottleneck 7.65mmx21mm Parabellum Luger cartridge.