Gotta say, this thread makes me itch.
Thousands of us have paired 240XTP’s with Marlin 1894’s for many years with fine results on deer. Don’t overthink it. Yes, the XTP is a common cup and core bullet and as a JHP, it expands pretty violently, sheds some weight, and can separate from the core - just as any cup and core JHP can. Guys only realize these “bullet failures” because they opened up the dead deer the bullet DID NOT FAIL TO KILL, so you really have to ask yourself - is a jacket separation inside a dead deer a failure? I’ve killed on the order of 25 or so whitetails with 44mags punting XTP’s, more with the same bullet in 357, 41 mag, 32 H&R, 45colt, 454 Casull, and 480 Ruger.
It was not accurate above when stated the XTP is rated for 1600fps, as the Hornady spec, widely available for this line of bullets, reflects expansion between 900 and 1750fps. It was also randomly speculated that a “max load” of 4227 would exceed 1800fps, however, Hornady 10th puts the 240 at 1700fps over a max charge of 4227 of 24.2grn.
Personally, the Deep Curl has never impressed me - it’s simply a thickly PLATED bullet.
JSP’s like the Nosler Sporting Handgun, Remington or Winchester won’t expand as violently, so they may be SLIGHTLY less apt to shed mass or separate core from jacket, but the same potential remains for any non-bonded cup and core bullet if pushed too fast into something too hard. I killed a lot of deer with Winchester “White Box” semi-jacketed JSP’s and had more regular jacket separation than I have with XTP’s - but again, the only reason I know this is the fact I stuck my hands inside the dead whitetail and found the bullets.
If you want a truly reliable bullet, then a Swift A-Frame is the way to go. Unnecessarily expensive to kill a whitetail, when a simple, inexpensive XTP will do perfectly fine, but if you’re really overly-concerned with internet rumor mills, the A-Frame would offer a lot of peace of mind.
For reference - I’m planning to take my deer in 2wks with a 300XTP pushed to about 1400 from a 44mag SBH.