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unspellable · 02-27-2003, 02:33 PM

In terms of pressure, the toggle action is inherently a vary strong design. Witness the extremely hot loads for the original DWM Parabellum carbine. These ran on the order of 40,000 cup. This sort of pressure is absolutely guaranteed to blow a 1911 to smithereens.

Actually the weak point in most self loaders is in the area of the ramp where the case head does not get very good support. Over pressuring the Parabellum will typically blow out the case head on the underside and take off the lower front edge of the breech block

You are more likely to break the Parabellum with too much impulse than with too much pressure. Impulse is the meaure of the cartridge's ability to shove the recoil operated action back, and relates to bullet weight and velocity rather than pressure. This type of abuse typically results in breaking off one of the toggle knobs or the rear extension of the rear toggle link. Of course mismatched parts that are ill fitting reduce the enherent design strength. Any slop allows parts to take a run and build up speed before they hit something.

The Mauser broomhandle is actually an incredibly strong design in terms of pressure. There are cases of the 9 mm Parabellum cartridge being fired in the 7.62 mm broomhandle without blowing it apart. This would obviously involve some incredible pressure as the 9 mm bullet gets swaged down to 7.62 mm. In today's world we find many broomhandles with rounded off or battered locking lugs which allows them to unlock too easily. There are cases of bolt fractures, probably due to the effects of age and quality control issues in the original steel. This is why the old guns are a bit variable and sometimes do not prove to be quite as strong as the design would indicate.

We get stonger and more consistent steel these days even if we don't get the hand finishing any more.

02-27-2003, 02:33 PM	#8
unspellable User Join Date: Jun 2002 Location: Iowa Posts: 768 Thanks: 0 Thanked 19 Times in 11 Posts	In terms of pressure, the toggle action is inherently a vary strong design. Witness the extremely hot loads for the original DWM Parabellum carbine. These ran on the order of 40,000 cup. This sort of pressure is absolutely guaranteed to blow a 1911 to smithereens. Actually the weak point in most self loaders is in the area of the ramp where the case head does not get very good support. Over pressuring the Parabellum will typically blow out the case head on the underside and take off the lower front edge of the breech block You are more likely to break the Parabellum with too much impulse than with too much pressure. Impulse is the meaure of the cartridge's ability to shove the recoil operated action back, and relates to bullet weight and velocity rather than pressure. This type of abuse typically results in breaking off one of the toggle knobs or the rear extension of the rear toggle link. Of course mismatched parts that are ill fitting reduce the enherent design strength. Any slop allows parts to take a run and build up speed before they hit something. The Mauser broomhandle is actually an incredibly strong design in terms of pressure. There are cases of the 9 mm Parabellum cartridge being fired in the 7.62 mm broomhandle without blowing it apart. This would obviously involve some incredible pressure as the 9 mm bullet gets swaged down to 7.62 mm. In today's world we find many broomhandles with rounded off or battered locking lugs which allows them to unlock too easily. There are cases of bolt fractures, probably due to the effects of age and quality control issues in the original steel. This is why the old guns are a bit variable and sometimes do not prove to be quite as strong as the design would indicate. We get stonger and more consistent steel these days even if we don't get the hand finishing any more.