The Firing Line Forums - View Single Post - 9mm: Why pick one bullet weight instead of another?

BillCA · July 21, 2008, 01:58 PM

As others have said, many pistols will favor a certain weight of ammo over others.

Redneckrepairs' Browning HP is probably an older gun made prior to the mid 1980's. Like my older S&W Model 39's, these older series guns seem to favor the 115-grain bullets. Using 124 grain ammo will work fine, but the accuracy is best with 115-grain.

My later 9mm guns - a Glock, Kahr K9, Beretta 92FS and a S&W 3914 were all built in the 80's or later. These guns tend to favor the 124-grain bullets for best accuracy.

Why is this? So far as I can tell, the twist rates haven't changed from 1:16, but it seems the 124's do work better in the newer guns.

I'd work up about 30 rounds each of 115g and 124g loads at the same velocities or similar energy levels and shoot them for accuracy. This way, you can determine which bullet is more accurate in YOUR gun.

July 21, 2008, 01:58 PM	#16
BillCA Senior Member Join Date: November 28, 2004 Location: Silicon Valley, Ca Posts: 7,117	As others have said, many pistols will favor a certain weight of ammo over others. Redneckrepairs' Browning HP is probably an older gun made prior to the mid 1980's. Like my older S&W Model 39's, these older series guns seem to favor the 115-grain bullets. Using 124 grain ammo will work fine, but the accuracy is best with 115-grain. My later 9mm guns - a Glock, Kahr K9, Beretta 92FS and a S&W 3914 were all built in the 80's or later. These guns tend to favor the 124-grain bullets for best accuracy. Why is this? So far as I can tell, the twist rates haven't changed from 1:16, but it seems the 124's do work better in the newer guns. I'd work up about 30 rounds each of 115g and 124g loads at the same velocities or similar energy levels and shoot them for accuracy. This way, you can determine which bullet is more accurate in YOUR gun. __________________ BillCA in CA (Unfortunately)