Sorry if it's been asked before, but I figure this is the best place to get an answer.

I have a Kel-Tec 16" 9mm defensive carbine that I have sighted with 115gr ammo.  It will shoot within an inch at 25 yards (longest indoor range) and I can easily hit the corners and edges of a 6 inch gong at 75 yards.

I found out that wal-mart sells the 147gr JHP version of the 115gr JHP I have been using for the same price.  I would like to throw a heavier bullet, since KT has yet to come out with a 45 carbine.

Will the heavier 147gr bullet have a noticibly different trajectory out of a 16" bbl? We're talking combat accuracy here.  I am satisfied that I can hit what I'm aiming at with the 115gr.  Will I have to completely re-sight the carbine?  If I do, I may not want to switch because I use 115gr ball for practice and it is the more common weight.  I'd rather hit what I aim at with 115gr than be uncertain with 147gr.

I know the best way to find out is to try it, and I intend to.  But you guys often give an excellent baseline opinion, and I can't get to the range for a while...

thanks

Thanks!

that's a good test of velocity comparisons, any body know about trajectory <edit: SBR beat me to it>?  Is there an online ballistics calculator for this sort of thing?

Quoted: Really wont matter until you try to "mail" them 147's out past 50-75yd, as the 147's will start dropping like a rock. I shoot 115's from the Uzi and MAC 10" pipes at 100, they go right on out there, with the 147's, its' hike the front sight up a bit above the target.

100 yards is my maximum range for the carbine.  It is my trunk gun and will probably only ever be used defensively at distances less that 50 yards, Indoor ranges are most likely.

thanks Matt

Quoted: As promised, here's a web based ballistics calculator.

that's a good site, but how do I find the ballistic coefficient of a 9mm jhp?

ZNevermind, I found it on winchester's website.

thanks again