Bergmann Bayard M1910

azlaw · 07-06-2008, 12:21 PM

This is straying into a reloading discussion, but...

Since you ask, the external dimensions among 9mm Largo, Bayard, and Steyr are in fact slightly different. This was intentional. I understand that this was due to a need to avoid patent infringements among gunmakers who all wanted to do the same thing, but didn't want to pay royalties. The Steyr guns will chamber and function with the 9mm Largo cartridge, but should not be used with Largo loads. Largo rounds are significiantly "hotter" loads than the older Steyr and Bayard. .38 Super was a lot hotter when it came along later, but was also the same idea.

We are using Starline 9mm Largo brass, with Hornady 9mm Largo dies and a Dillon 9mm crimp die. I will post the data when I get back home next week.

9mm Largo
Bullet Diameter:.355
Neck Diameter: .379
Base Diameter: .390
Rim Diameter: .392
Case Length: 0.91
Cartridge Length: 1.32

9mm Bayard Long
Bullet Diameter:.355
Neck Diameter: .375
Base Diameter: .390
Rim Diameter: .392
Case Length: 0.91
Cartridge Length: 1.32

9mm Steyr
Bullet Diameter:.355
Neck Diameter: .380
Base Diameter: .380
Rim Diameter: .381
Case Length: 0.90
Cartridge Length: 1.30

07-06-2008, 12:21 PM	#6
azlaw User Join Date: Mar 2007 Location: Tucson, AZ Posts: 207 Thanks: 1 Thanked 4 Times in 4 Posts	This is straying into a reloading discussion, but... Since you ask, the external dimensions among 9mm Largo, Bayard, and Steyr are in fact slightly different. This was intentional. I understand that this was due to a need to avoid patent infringements among gunmakers who all wanted to do the same thing, but didn't want to pay royalties. The Steyr guns will chamber and function with the 9mm Largo cartridge, but should not be used with Largo loads. Largo rounds are significiantly "hotter" loads than the older Steyr and Bayard. .38 Super was a lot hotter when it came along later, but was also the same idea. We are using Starline 9mm Largo brass, with Hornady 9mm Largo dies and a Dillon 9mm crimp die. I will post the data when I get back home next week. 9mm Largo Bullet Diameter:.355 Neck Diameter: .379 Base Diameter: .390 Rim Diameter: .392 Case Length: 0.91 Cartridge Length: 1.32 9mm Bayard Long Bullet Diameter:.355 Neck Diameter: .375 Base Diameter: .390 Rim Diameter: .392 Case Length: 0.91 Cartridge Length: 1.32 9mm Steyr Bullet Diameter:.355 Neck Diameter: .380 Base Diameter: .380 Rim Diameter: .381 Case Length: 0.90 Cartridge Length: 1.30