S&W recommends to its LE armorers that recoil & magazine springs are replaced either every 5 years or every 5,000 rounds.
Feeding issues can be caused by worn out recoil & mag springs. Order some factory springs and try things again. Yes, I said factory springs.
A live round jumping the mag lips to get in front of the extractor might be caused by a damaged recoil spring (worn out, badly kinked, cut, etc). Increased slide velocity & battering can cause this sort of feeding problem, as can weakened mag springs (letting the top live round become displaced from under the mag lips, due to recoil forces, before the slide has run back forward far enough so the extractor can capture the rim).
The standard 4506 recoil spring is Part #20161000. You're talking about a buck & a half for a new factory spring. (They also offer a "wadcutter" recoil spring for lighter target loads, Part #20071000, or a recoil spring pack, which contains both the standard & wadcutter springs, Part #19302000.)
The mag springs are the same for all the 3rd gen .45's (6, 7 & 8-rd mags), Part # 262600000.
If the raised center "nub" of the black plastic follower is worn through, you can order new followers, Part #23674000.
Failure-to-
eject, or an erratic ejection pattern, can be caused by a damaged ejector. That's an old enough gun to probably have the older, short ejector. Can you post a pic of the ejector (slide removed)? The subsequent revision of the ejector incorporated a couple improvements. One was a longer tip, for faster and more positive ejection. The other was the elimination of a sharp corner angle underneath the tip, which helped prevent a stress riser (that could sometimes result in a broken tip). A smith familiar with 3rd gen guns can drop in a new .45 ejector easily enough.
Failure-to-
extract can have other causes involved. Usually it's a damaged (worn out) recoil spring, or either a damaged extractor and/or a weakened extractor spring. This is NOT a kitchen table smithing project, either.
Replacing an extractor requires a Go/No-Go bar gauge so the new extractor can be filed & fitted, as well as a Force Dial Gauge so the proper extractor spring tension can be achieved. S&W has "standard" weight extractor springs, as well as Heavier & Lighter tension springs, so the proper tension can be achieved in any particular gun. Older machining methods could sometimes result in some tolerance variances in the depth of the extractor spring hole, as well as its shape at the bottom (which could affect how the spring sits in the hole).
Both ejectors & extractors come in both "plain" stainless finish and black finish, BTW. Depends what they may have in-stock at any moment.
That's an older gun. First thing I'd do is re-spring the gun (stock recoil & mag springs).
I'd inspect the ejector & extractor to check for damage (chips, cracks, breakage, etc). Repair of either will usually involve a trip to the factory or a gunsmith familiar with S&W 3rd gen guns.
Just my thoughts.
