Short barrel power loss

[militant]

I have a kel tec pf9. I carry corbon 125 gr plus p in it but after looking at the velocity and ft lbs out of such a short barrel, would it be worth it to switch to fmj to get the penetration needed for self defense?

[Mrgunsngear]

No. The slower (to a certain extent; there is a point this isn't true) your rounds are going the more they'll penetrated. Again, this is within a certain range; the range your rounds would almost certainly be in coming out of your PF9 at SD distances.

[Bill DeShivs]

The 9mm has plenty of penetration, even with light hollow points.

[jimbob86]

I shoot a Springfield EMP, which has a 3" barrel. It clocks 80-100 f/sec less than the boxes of Hornady Custom claim... but the XTP's open up just fine in water filled milk jugs, and critters....

[Gaerek]

Here's a good rule of thumb that pretty much applies to everything:

Don't use FMJ for defense.

[Edward429451]

No, the 9mm is not lacking in penetration, and the FMJ bullets in 9mm are a poor design for SD because of the pointy design and small caliber.

Here's a good rule of thumb that pretty much applies to everything:

Don't use FMJ for defense.

However, I totally disagree with this statement. It does not pretty much apply to everything, it pretty much applies to 9mm in particular. In a lot of cartridges with less power than 9mm, fmj could be good because of the added penetration of the fmj's. In larger calibers, fmj's will work fine because of the added weight & sectional density, and if velocity is high enough to make two holes...so much the better.

Each cartridge has it's own range of velocity, weight, and sectional density and therefore must be considered individually. It is very hard to make blanket statements with any accuracy about cartridges.

[griff383]

FMJ can be a necessity depending on the situation so the previous blanket statement doesnt always hold true.

I use FMJ in my LCP in the winter, I need all the extra penetration I can get with that little round. Thats not to say I dont carry something bigger in the winter.....

[Bill DeShivs]

Back in the Jurassic period, .32s, .380s, and 9mms were considered marginal for defense. Then, innovative ammunition companies designed hollow point bullets for them. At that point, the general consensus was that expanding ammunition (that worked) made the cartridges viable. Then, the misguided, misquoted, and misunderstood "FBI statistics" came out-and set defense ammunition useage back 30 years.

[RBid]

The PF-9 will still get 1100+ fps from Speer Gold Dot 9mm +P 124gr, and I would assume similar velocity from comparable rounds.

The 'short barrel' version of that load will get you back 50fps or so lost from running the standard version of that round through a shorter barrel.

[481]

Originally Posted by militant:

I have a kel tec pf9. I carry corbon 125 gr plus p in it but after looking at the velocity and ft lbs out of such a short barrel, would it be worth it to switch to fmj to get the penetration needed for self defense?

If you have access to a chronograph (or if you can borrow one from a friend) you might consider seeing how fast they are moving from your gun. Knowing that number, a simple call (or e-mail) to Corbon inquiring as to the "velocity floor" for expansion of that round should tell you if you can keep this load or if it's time to reconsider your options.

[Crankgrinder]

Dont use ball ammo for sd.

[seeker_two]

Originally Posted by Crankgrinder

Dont use ball ammo for sd.

Why not?

[warnerwh]

In both my Keltec PF9 and Ruger LCP the chambered round is a gold dot but the magazine is full of FMJ rounds. My reasoning is reliability. I can't afford to buy a couple hundred rounds of Gold Dots for each gun to test reliability. Also a solid will work fine if you can shoot well. Small autos tend to be the most likely to malfunction and that could cost you your life.

[Dashunde]

Dont use ball ammo for sd.

Because it wont really expand and give the best results possible.
A lot of fmj isnt full power, read the box and use the good stuff if thats what you want to use.

I wanna know what "critters" Jimbob is shooting with a 3" 9mm?

[10mmAuto]

I wanna know what "critters" Jimbob is shooting with a 3" 9mm?

My first handgun hunting weapon was a Glock 20 which I use for Elk, .45ACP, .40 and 9mm are all inadequate for full size game although I know a few handgunners who have done it with 1911s in .45 super - but I've killed feral pigs with a my girlfriend's commander sized 1911 in 9mm and coyote and a mule deer with a Glock 34.

If those count as critters. I wonder, since you're so dismissive, if you've shot a lot of game/non game animals with pistols? I've taken game with .45ACP, 10mm, 9mm, .40 and .357 Magnum. Just a thought. Everybody seems to be an expert, even the people who have never done what they're an expert on. Not saying you are in that predicament (that you have not taken game with auto pistols), but seems to be a hot trend on the interwebs.

[10mmAuto]

In larger calibers, fmj's will work fine because of the added weight & sectional density

Look up sectional density. You must mean diameter. In any case, strongly disagree, especially with the idea of two holes being better. Sounds wildly irresponsible and like a manslaughter trial in the making when you dust the wanna be gangbanger and kill grandma behind him.

As a side note about why I strongly disagree, larger calibers are less disadvantaged as a FMJ because of their inherently larger wound channel with non expanding ammunition, but that's still suboptimal when you compare it to the outcome you'd get with hollowpoints. Just get the hollowpoints.