Does +P matter?

[Slalom.45]

Reading the recent "Best .380 ammo" thread I saw and read the ballistics tests posted on various 9mm loads. Most all of the loads are +P.

I have been carrying 124gr HST standard pressure for some time. My thought was that I shoot standard pressure 115-124 gr range ammo, the SP HST shoots to a very similar point of impact, why not carry roughly what I shoot vs +P 124gr or 147gr? I have also seen here looking through archives where 147gr +P is actually not recommended over 147 standard pressure. If so, is it really that big a deal in 124gr?

My thought is that this issue is so far down the list of importance as to not be a factor in the "real world", but I have wondered if my thinking is off here.

Thanks in advance for any input...

[PNWTO]

While there exist far more qualified people on this forum than myself, I would say that no... +P doesn't really matter. The moneyshot has always been accurate delivery to the right tissues. Know your capabilities and be aware of your bullet. Again, there are better people than I but I believe my reply is a good start.

[Nephrology]

I think the best answer is "it depends." In 9mm, 124gr and 115gr loads seem to typically come in +P flavors and that probably makes sense. If you lower bullet mass, increasing velocity is the best way to get the right momentum necessary to penetrate to FBI requirements. The reverse is true as well. You probably don't need a +P 147gr 9mm, however.

Just my 0.02 USD

[Slalom.45]

I'm not sure about the velocity equaling more penetration. It seems that I have seen some ballistic gel test (TN9 maybe?) where the non +P version of a load actually penetrated better than standard pressure. I would think that more velocity would equal more expansion which could lessen penetration. Of course that is a trade off in and of itself. (All my guesswork, nothing at all to back it up)

Also. Why would Federal, or any company, offer +P and standard pressure loadings if one is obviously superior to the other?

[Velo Dog]

http://www.le.vistaoutdoor.com/downl...sertPoster.pdf

http://www.le.vistaoutdoor.com/downl...dDotPoster.pdf

Standard pressure 124 grain 9mm should be fine, especially in 4" or longer barrels.

[Velo Dog]

Sorry, there really wasn't a good reason for posting this video.
Watch the next video for commentary from tnoutdoors9 on his observations on the differences between standard and +p loads.

[Velo Dog]

[RevolverRob]

+P borders on necessary to very necessary when directly related to barrel length and the necessary velocity to cause expansion via whatever mechanism is designed by the bullet maker.

Longer barrels, produce more velocity, means that lower pressures can be used to get reliable expansion.

Shorter barrels, produce less velocity, to get to equivalent velocity for reliable expansion they will require more pressure.

It's a pretty basic physics equation all said and done.

And the question becomes - Do current bullet designs perform optimally at the lower-end of their performance envelopes to expand effectively? If the answer is yes. Then +P shouldn't matter. If the answer is No. Then +P matters. It seems - almost regardless of medium shot through - that most bullet designs today heavier than 135-140-grains can perform optimally at velocities in the 850-1000 feet per second (that's an anecdotal observation and is dependent on bullet type, jacket type, etc). But bullets lower than these weights seem to perform optimally at 1050+ feet per second. FYI, this is regardless of the overall diameter of the bullet.

Bottom line - pick the load(s) that you can get a reliable quantity of, you know you can shoot, and pick a trusted brand and bullet type for your handgun. If you're handgun caliber is marginal (i.e., not a service-sized Caliber), then going heavy and hot probably isn't the worst idea on the planet.

FWIW - Heavier bullets at higher velocities always penetrate more. The harder, heavier, and faster the bullet the deeper the penetration. If you're concerned with over penetration slow the bullet, lighten the bullet, or soften the bullet, or all three.

[Unobtanium]

Propelling the bullet to optimal velocity is what matters. If your chosen pistol require plus p to hit the velocities at impact that the projectile was engineered for, then I'd use it. If using it pushes you OVER the optimal, then I'd say it's actually bad. Think of velocity with a handgun bullet as you do air pressure in your car's tires.

[Slalom.45]

Agreed. But looking at the HST test chart listed above by Velo Dog it looks like expansion of both standard pressure and +P are excellent. In fact penetration is extremely close with a slight edge to +P in glass and through plywood. This might be a factor if you are a highway patrolman, but as a CCP holder it seems that standard pressure will be very effective with modern ammo. If so, why fight the extra recoil and muzzle flash? Especially if the ballistics more closely match your practice ammo.

Fun discussion...