I would assume this is safe, using +P+ 9MM ammo in an OLY upper. Has anyone tried this, and results or opionins? Thanks.

I'd stay away from it in a M16/AR15.

The 9mm uppers (Colt, Oly..) are VERY strong.  They are built the same as sub-gun uppers and will handle the hot sub-gun ammo w/o a problem.

I would think the +P+ would put alot more stress on your fire control parts and transfer to your lower.

I would not use it in a M16.

IIRC, someone from OLY posted on this a while back, and they said +P+ was ok for use in their uppers.

An ar barrel is jsut a wee bit thicker than a pistol barrel. [;)]

i would be leary of using it in a barrel longer than the 10.5" SMG barrel.  my thought is that it would increase the bolt speed in 16" barrel due to the longer bullet dwell time in the barrel.  same reason the 9mm smg guys say their guns run cleaner than the guys with 16" barrels.  ie... it is a blow back.  higher bolt speed = more stress on weapon.

There are a few who are a little skittish about putting hot ammo through their guns, but the sub-gun is the [b]LAST[/b] firearm you have to worry about concerning +P+.  

Most handguns are designed to fire +P+ but only in limited quantities due to excessive wear.  The sub-gun is like an overbuilt pistol....[i][b]WAY[/b][/i] over built!  The AR15 is designed to fire high preassure rifle rounds and they withstand that all day.  A hot pistol round is nothing.  

Someone not wanting to shoot +P+ is perfectly OK, it's their rifle. What I'm saying is if [b]YOU[/b] want to do it feel free!!  The Oly will run +P+ all day w/o a problem. Hell, fire +P++ if you want! Hertenburger sub-gun ammo I think falls into the +P++ catagory: they label it "For Sub-gun only".

BTW, slower bolt speed means cleaner weapon cause most of it gets blown down the barrel before the bolt breaks the breach.  You can acomplish this by stretching out your recoil spring or ordering a wolf spring.

Thanks for the info gentlemen.