"Power"

[TBT]

Multiply the bullet weight ( in grains) times the muzzle velosity (fps) and divide that number by 1,000. That will give you the power factor number of a particular cartridge.

How accurate is this formula?

I'm looking to find a new carry ammunition since I'm growing tired of the supply and demand of the Ranger +p+ ammunition that I currently carry (I find myself waiting on shipments because the dealers are out of stock etc.) and have decided to give DA's favorite Georgia Arms a try at last.

Looking at their specs on their 9mm and using the formula I get the following:

Maker Grain FPS Power Factor
Georgia Arms 115+p+ 1300 149.5
Georgia Arms 124+p 1200 148.8
Georgia Arms 147+p 1050 154.35

Does this tell me that the 147+p is the best choice for the 9mm?

["DoubleAction"]

TBT; Bullet weights and velocities might equate to the same results in a formula such as the one used to calculate the power factor. I prefer velocity over that of bullet weight, with bullet diameter and bullet design considered in the equation. Georgia Arms loads their +P "Power Plus" ammunition, using Gold Dot Bullets on Starline Brass. The 147 gr. bullet is a bit heavy for the 9mm cartridge; I use only 135 gr. bullets in the .40 S&W Corbon loads and 125 bullets in the 357 sig. My 38 Super has 130 gr. Gold Dot bullets.

The penetration and wound channel characteristics of a defense cartridge often dictates how it will be received. The Power Factor formula only provides a balancing act between what one might achieve through the use of cartridge cases, bullets, and powders for a particular cartridge. Much of the power factor numbers might apply to recoil, rather than the defensive attributes of a cartridge.

[TBT]

So ... go with the 115+p? lol

This is so confusing. I was using 124+p+ Rangers for the last year or so. Loved those things.

["DoubleAction"]

TBT; Either cartridge should provide you with your expections in the 9mm for defensive applications. Velocities of 1200 to 1300 fps is plenty for the 9mm. How well you shoot, using certain ammunition, also plays a big role in your choice.

[TBT]

I'm thinking about the 124grain @ 1200fps.

["DoubleAction"]

tbt said:

I'm thinking about the 124grain @ 1200fps.

TBT; I think you have arrived with a good balance between bullet weight, design, and energy, which I believe to be very adequete for the size of the 9mm cartridge.

I had something happen to me a few years ago with the Georgia Arms Gold Dot loaded .45 acp +P. One day a friend stopped by my house to show one of his new 1911s; after disassembling and reassembling the piece to smooth up the action, he asked if I had the time to go to the range. I was running low on FMJ .45 acp at the time, so I decided on taking along a box of georgia arms 185 gr. + P Gold Dots with my Colt Combat Commander. I had never shot the Commander as well on any other day as I did on that day, every shot fired landed inside the ten ring.