What are some good rounds for use in the polygonal rifling of a USP 45?
Ball/Practice?
JHP's (pref 230gr)?

Thanks.

Shooting lead bullets in polygonally rifled barrels:

Supposedly a major cause of firearm Kabooms! this "common knowledge" is actually a myth. A myth that has caused many a pistolero to shun this extremely cheap source of practice ammunition, ignorantly (albeit just cautionarily) wasting a lot of money on jacketed ammunition for practice use. Note that for carry or self-defense purposes a JHP that reliably feeds and fires in one's gun should be used unless one has special requirements like armor piercing for well protected targets or frangibles to reduce risk of over penetration.

This myth most likely started after a number of people destroyed their glocks after shooting a round that produced excessive pressure. The theory was that the lead built up too quickly in polygonally rifled barrels and was in effect obstructing the path of the fired bullet. Although it is true that lead does build up faster than jacketed ammunition (in both conventional land and groove and polygonally rifled barrels) thoroughly cleaning the barrel every 100 rounds is enough to keep shooting lead in polygonally rifled barrels safe. Another method is to fire one jacketed bullet for every 10-15 rounds of lead to remove the build up. With this method, one can safely fire 200 rounds of lead in between bore cleanings and still keep pressures within safe levels.

After a shooting session with lead, clean up using Ed's Red or some Hoppes #9 to get all the gunk out. Lead ammunition is a bit more dirty compared to jacketed rounds as aside from powder and primer residue, there is the matter of lead and lubricant residue to take care off. Pay attention to these details and you will be rewarded with the most economical ammunition money can buy. And since lead is softer than copper, with proper care your barrel will last longer than if you exclusively used jacketed ammunition.

Based on that, for practice ammo, I would just stay with any jacketed bullet.

Go to China Mart (WalMart) and buy the WWB 230gr FMJ for around $24/100rds or the Blazer 230gr FMJ for $9.97/50rds.

carry: Win Ragner Ts, Speer Gold Dots, and Federal HSTs

plinking/practice: WWB

The WWB value pack at China uses a brass jacket that makes the bullet shoot for crap accuracy. I can't hardly hit the 25m NRA pistol target with it in my USPC. It is seriously terrible. I have heard of some WWB with "improved accuracy bullet" on the box, and supposedly it is copper jacketed and will shoot fine. I have seen pics of this in 9mm, but I don't know if it can be had in .45. It isn't at my local China.

For practice, Blazer and Blazer Brass have been good for me. UMC is also good. The 50 round boxed WWB at my local gunstore is very accurate. I qualified for my CHL with it and got a perfect score. I should research the product codes for WWB and post about their differences. It doesn't make sense for the 50 round box stuff to shoot well and the 100 round box stuff to shoot for crap.

I have not shot Wolf, but some say it's ok and some say it's not.

I carry 185 grain +p Gold Dots. Remington Golden Sabres are just as accurate, but I have noticed core sperations with it when shooting junk at the range. Prety much any premium JHP should suffice, but my internet research and very causal testing has lead me to chose Gold Dots. In a full sized USP I might carry 200 gr. +p Gold Dots. The 230 gr. standard pressure Gold Dots have not expanded sufficiently in my experience, but this may be due to my short barrel.