Let's say I'm going for better accuracy on a target-type 9mm pistol using .355 bullets.  I typically use RMR, Hornady XTP, etc and get good results.  What would happen if I tried using a rifle-type bullet of the same diameter, and of similar weight? Assuming it would feed in a semi auto pistol and fit into the chamber, would accuracy (especially at longer distances) improve?  Or would I not be able to drive it fast enough to notice a difference?  I know they're pricey, and I have no intention of making my X5 Legion into a test gun, but I'm wondering if anyone else has tried this, and what would happen if one did try?

Thinking something like this...Hornady's 165gr .355 FTX bullet:

Longer bullets may not stabilize depending on the twist in the pistol coupled with pistol vs. rifle velocities. I'm not sure there would honestly be much gain. I suspect the vast majority of accuracy deficiency in many pistols lies with the shooter as opposed to the load.

You want accuracy in 9MM look at 9MM 125gr HAP with Power Pistol.

All good points and I agree - and I'll put myself in that crowd of being the weak link in the accuracy process.  Thanks for the input.

I'll keep that in mind - I've never really loved using the HAP series, but maybe it's becasue I tried to use it with Titegroup and Bullseye.  I do like the XTP124, and it's my "go to" bullet for 9mm.

RMR and Precision Delta make JHP bullets very similar to the Hornady HAP.  If the HAP did not shoot for you, then it had to be the particular loads or bullet weight you were using.

I'll probably try them again.  In the past, I was probably judging them based on their performance in slightly lesser / shorter barreled pistols.  I have the X5 Legion and Shadow 2 now, and am really enjoying more accuracy in 9mm than I ever did before.

I do use RMR's "Multi Purpose Round" and Match Winner (124 grain) and both have been great, especially for the price.  I just picked up CFE Pistol to try, and may have to try a couple others as well.