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bozhoz · December 3, 2009, 01:46 PM

I would guess chrony error- buy some regular rounds with stated velocity on the box and double-check the accuracy of the chrony. 1700 fps sounds REALLY fast in a 9mm 124 gr. I would think if it was truly that fast, the gun would blow up. I know the relationship is by no means linear, but just some napkin math using IMR powder and 124 grn, velocity 1015, pressure, 27,700 PSI; velocity 1115, pressure 32,700 PSI- starts to put us in the 50,000 PSI range at 1700 fps. I would really think something at that PSI would feel a lot more substantial than just a stout load and should probably be causing some major damage to the firearm. Again, numbers seem way too high to be real, so I would really double check the chrony.

December 3, 2009, 01:46 PM	#2
bozhoz Member Join Date: March 15, 2009 Posts: 82	I would guess chrony error- buy some regular rounds with stated velocity on the box and double-check the accuracy of the chrony. 1700 fps sounds REALLY fast in a 9mm 124 gr. I would think if it was truly that fast, the gun would blow up. I know the relationship is by no means linear, but just some napkin math using IMR powder and 124 grn, velocity 1015, pressure, 27,700 PSI; velocity 1115, pressure 32,700 PSI- starts to put us in the 50,000 PSI range at 1700 fps. I would really think something at that PSI would feel a lot more substantial than just a stout load and should probably be causing some major damage to the firearm. Again, numbers seem way too high to be real, so I would really double check the chrony.