The Remington UMC is very good ammo, just like the Winchester White box, it shoots a little dirtier than more premium ammo, but that really isn't a biggie when you are cleaning a gun anyway. The ballistics are the very same as the Green and Yellow and really pricey Remington Express ammo.
I do buy the UMC 100 count value boxes and mostly in JHP in .380, .38 special, 357 Mag and .45 acp. I don't buy the Yellow Box 250 count fmj as I like bullets in the cardboard separating jackets or racks as opposed to being loose, but that is just me.
I've never seen the FMJ 250 count bulk as being that good of a value, as the Federal Champion FMJ rounds are generally better priced in even boxes of 50 whenever Walmart has them, and I think the Federal burns a little cleaner.
Nearly anywhere you find the 100 round value-packs of Rem UMC jhp, then the value grows. In my .380 pocketgun, the round offers the best of both world's. 1. For a hollowpoint, it has a small cavity and the bullet is most like a round nose (fmj) in shape and is less problematic for feeding in a pocket gun than a wide mouth hollowpoint.
2. It's hard to get a good balance in .380 between expansion and adequate penetration. The small cavity hollow point will give some expansion and better overall penetration.
I doubt it really matters that much out of a .357 magnum as the ft lbs of energy involved are gonna turn some one inside out anyhow and a .45 is never smaller than .45 hundredths of an inch!