I've been loading cast lead 100 gr RNFP bullets for the past several years and have never, ever had a FTF, double-feed, or any other hangup shooting them in my Sig P232.
I recently loaded up 50 rounds of Winchester 95 gr RNFP jacketed bullets - loaded to the same COL as the ones I measured from a factory white box of the same bullet. Out of the 50 I loaded, I had at least three double-feeds or hangups - I can't even remember what all happened as I got frustrated during all of it. I do know that twice when I racked the slide back to load the first round into the chamber the round failed to feed in properly and I did a tap-rack and ended up getting the resulting double-feed mess all stuck so tightly that it was all me and my buddy could do to get the magazine pulled out of the gun.
I do not remember how I set up my seating die, but my first thought is that I must not be taper-crimping any at all, or not enough, and with the jacketed bullet likely being harder than the cast wheel-weight lead bullets I've been using that the case mouth of the bullet is not squished down enough to avoid problems. I'll have to measure them with my calipers to see if there's any difference.
Any ideas? FWIW, my Sig 232 has never, ever had any sort of malfunction with any other ammo, factory or reloads, except for these recent 50 that I loaded.

take the barrel out of the gun and plunk test your loads after crimping

I have a Dillon gauge for each caliber of semi-auto ammo I reload. I gauge each round prior to putting it in the box. This will ensure a correct diameter of each piece of brass and overall length of the cartridge. These gauges run $15 to $20 each depending on the caliber. I load a lot of .38 special and use an old revolver cylinder for much the same thing.

Bullet seating depth is often a critical element for reliable feeding and functioning. The bullet you're using may not be exactly the same as the "same" factory bullet. Crimping might be a problem as well. Taper crimp may have to be within specs, but usually only enough to hold a bullet in place and no more. Experiment and do the chamber drop test as you proceed. You'll get it right.

I use a case gauge only for AR guns. If you can use a chamber as a gauge, that should be all you need, but a real gauge may be handier.

Case tension alone should hold the bullet in place securely. If it is not, your bullet expander plug is too big. The taper crimp is for removing the flare from the case so it feeds smoothly.

Your case bell expander is likely set too deep, then the crimp too light. When you reload next time, closely check the bell that is formed at the case mouth at the powder stage, back it out slightly. Measure and compare to specs. Then at the crimp stage, measure carefully. In each case, use a good quality caliper or better a micrometer and compare a few. You likely made some out of spec. For 1 thing, lead will crimp far differently than a jacketed bullet, necesitating a tighter crimp on jacketed bullets, but only slightly tighter. Don't over do it, read the specs and follow them, including O.A.L., don't just compare by eye with factory loads.

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Certified NRA rifle instructor

So did you fire any other load/ammo after these suspect rounds? If not, you can't be sure it's the round.

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Dave

Yes, I fired an entire 50 round box of Winchester White Box without a single problem.

I did some measuring this evening an it seems that MY loads are a couple thousandths wider, on average, at the case mouth vs factory loads or my cast lead loads and don't feel as smooth at the transition from case to bullet as the factory loads do. I increased the crimp some and they feel better.
I didn't check the case mouth bell - what should it measure? I don't have any of my manuals in the house with me, but I don't recall seeing a spec. for the case bell.

When I started loading 380 ACP, after trimming the cases I had to make sure the mouth of each case was without any roughness, inside and out, before pressing the FMJ/XTPs and taper crimped properly. The same problem disappeared.
When I order bullets again they will be FMJFN.... but those 115gr XTPs are accurate as are the Penn 100gr leads at .355"

Plunk with each pistols barrel works for our 380 collection.
The S&Walther PPKs pistols required a shorter OAL because of the mags.

I bell the 'minimum' amount to get each type of bullet's base started.

I remember that the Speer Lawman cases had a thickening inside the case and made it 'not good' for my Hornady 115gr FMJRN.

I believe I figured out my problem. The 380 requires #4 shell holder and I believe I got the #4 from my .32 H&R die set inadvertently switch with it. They measure about .005-007" difference in thickness, even though they are the same shell holder by the same manufacturer. I reset all my dies and will try loading some new stuff.

RCBS #10 shell holders are for 380 ACP as well as 223 Remington.
Can 223 Rem cases magically become 380 ACP cases?
Can 223 Rem dies do some chores in making 380 ACP ammo?
380 ACP and quality small pistols are a great combo, when living in the Tropics, and a quality small 9mm is too large.
Works for me.

Even with a 380 ACP in my front pocket, when fishing, my M59 is carried as well.... since new in 1980.
Headed for a Texas trip soon and just want to be politically correct and make my buddies smile.

If you get so frustrated that you can't remember what you did, I suggest you take a deep breath and reconsider what you are doing. Being in that mental state while shooting can be dangerous to you and those around you.

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Minimize the variables