+p has less recoil?

[dekindy]

Shot from the same gun, Springfield Armory XD-E 3.8" barrel, Supervel regular 9mm and +p SCHP, both bullets 115 grain. Expected more recoil from the +P but it felt less.

Makes no sense to me. Any thoughts. Takes a 5" barrel to develop higher velocities?

Sent from my SM-G920V using Tapatalk

 

[Tombs]

Did you get chronograph results?

 

[churchmouse]

Did you get chronograph results?

^^^^^^^^^^^This^^^^^^^^^^^

 

[Alamo]

Did you get chronograph results?

Good question.

some years ago I chrono’d a wide variety of 9mm out of a Kahr P9. I was surprised to find that +P did not necessarily mean higher velocities for a given bullet weight - usually did, but not always. I would think that higher Pressures would yield higher velocities (and more recoil), but apparently not every time.

 

[STEEL CORE]

Federal 98BP is 115 gr +p and a sweet shooter (IMHO) did you shoot any of that?

 

[88E30M50]

Are you comparing the same bullet weights? Heavier bullets can give a heavier recoil feel

 

[foszoe]

Good question.

some years ago I chrono’d a wide variety of 9mm out of a Kahr P9. I was surprised to find that +P did not necessarily mean higher velocities for a given bullet weight - usually did, but not always. I would think that higher Pressures would yield higher velocities (and more recoil), but apparently not every time.

Yeah and sometimes +P+ is slower +P.

 

[Tactically Fat]

Also keep in mind that test barrels for the vast majority of these pistol rounds are 4" or so long.

There may not be enough barrel dwell time in a 3" barrel to give enough burn-time to develop the entire extra oomph.

However, 9mm +p is an official SAAMI designation. If the ammo is from a large manufacturer, especially one with Federal contracts, it's gonna be +p ammo.

 

[Tombs]

Also helps to remember, more pressure doesn't necessarily mean faster.

If it's a faster pressure spike, then less energy is put into the bullet's velocity. If it's too long of a pressure curve, then most the powder is burning outside of the barrel.

So it's easy to make a +P loading that is slower than a non +P loading.

On the time scales we're talking about, barrel length shouldn't be enough to change felt recoil.

 

[russc2542]

Could be a lot of things factoring into it. For one thing it's likely a different powder with a different burn rate. While, all else being equal, barrel length shouldn't be that much difference, if the powder burn rate is more appropriate for a longer barrel, it may. Load up on a slow burning powder and it's easy to make a very spicy load for a long barrel that's pretty much just a flashbang out of a short barrel. That kind of thing is much more apparent in a rifle because of the larger loads and longer barrels but the physics are the same for a handgun.

 

[KokomoDave]

My favorite is Hirtenberger +P+ 100gr PSP in my Glock 19 / 17 both Gen5 and my 43X. Quite fun in my P229 too!