+P Ammo Question

[SIGSHOOTR]

Can someone please tell me the advantages/disadvantages of +P ammo as a HD/SD round specifically as it pertains to 9mm JHP? SIG tells me my P226 can take +P rounds but not to make a habit of shooting it all the time-- only occasionally-- because it will shorten the gun's life. And they told me never to use +P+. Is there any reason to use this load? (I currently keep on hand 147 gr JHPs for HD/SD) Thank you.

[Knife Edge]

To recover lost velocity with heavier bullets. I can't think of any reason to do this for the average guy. HK will take +P+.

[iareConfusE]

Lighter bullets are loaded with +P or +P+ pressures to increase velocity, so that they'll expand more reliably, and have more penetration as well. It's true that constantly shooting +P loads through your gun will cause it to wear faster. Your Sig should be able to handle +P+ loads as well, but I wouldn't shoot it often at all. I'musing 147gr in my CZ P-01, I haven't really found it necessary to deliberate between 115gr +P+, 127gr +P, and 147gr normal loads. I just chose whatever was readily available that showed reliable expansion.

[iareConfusE]

To recover lost velocity with heavier bullets. I can't think of any reason to do this for the average guy. HK will take +P+.

Lighter bullets are usually loaded with a +P charge, not heavier bullets. It's counterintuitive, but if you use a really hot charge to propel a heavier bullet, you'll have dangerous pressures. Typically, the heavier the bullet, the slower it should fly. Trying to add more powder to make up for lost velocity is simply dangerous.

[odysseus]

Energy.

A lighter grain load in HP can use more velocity safely. In theory due to it being lighter in construction it is more likely to "fail" when it hits mass to expand and dump more of its energy.

Any modern pistol like your Sig will be fine. Now if you want a safe queen and are talking about wear margins 10,000 rnds later... well you decide.

[cmace22]

Also to gain velocity out of shorter barrel lengths.

[sigfan91]

It's all about energy. More pressure = more energy, doesn't matter how heavy the bullet is. It's easier to raise pressure on heavy bullets due to their mass. It's also more dangerous.

Does anyone need +P in SD/HD situation? That's up to the user. I figure +P might have more problem with over penetration. A modern hollow point should provide reliable expansion even in regular pressure rounds. Besides, you can always shoot the dirtbag again...

[SIGSHOOTR]

Thanks to everyone for all the great info! Much appreciated.