you may have nothing wrong with your sig at all. 1989 the barrel ramp was changed to allow jacketed hollowpoint, prior to that they were not designed for hollow points. all years accept ball rounds. date of production should be indicated on slide.
I only tried the Winchester Full Metal Jacket (which is sort of a tapered point but rounded and solid). The very tip of the rounded (but tapered) projectile is exactly what jambs in the gap between the free ramp on the from and the feed ramp on the barrel. The barrel is set back ahead of the ramp on the frame that is really seems it should not be an issue.
I bought that in a bulk box from Gander Mountain 500/box when it was on sale a few years back. Always functioned flawlessly in everything else, e.g. ALL my S&W autos from the earliest pre-39 to my newest 5906, the Beretta 92FS, Browning Hi-Power and even works fine in my son's 2 Bobergs which are both VERY finicky about ammo. It is a good suggestion ... I'll try some rounder tip ball ammo.
To look at the gap between the barrel feed ramp and the ramp in the end of the magazine column in the frame ... it all looks good, just a tad wider space than my 226s, 228s, 229s. And it seems to "float" just a tad more when the slide is locked back, as perhaps, worn a bit. The rifling in the barrel is excellent. Thank you.
I have nothing to lose by trying to use some red cutting / buffing rouge on a firm compressed cotton buffing bit on a Dremel to smooth it out a bit more. The feed ramp on the barrel seems to have raised borders or "curb" type "tracks" while the 226s, 228s and 229s do not have those "curbs" (Higher, raised, edges of the barrel ramp).
The slide spring is extremely hard to pull back but I've read that's characteristic to the P6. I'm even thinking about swapping out to a softer spring may give the bullet a split second loger for the tip to raise up as it slides out of the magazine.
