I want to change my captured recoil spring in my SW 9 mm Core with a new spring any thoughts on how to get the existing spring off the rod and installing new spring

Remove the bolt at the end of the rod , change spring and put the bolt back on the recoil rod ! Glock springs are the same spring too .
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I own two Equalizers and they fire 115 gr ammo great, but the slide lock drops, and the slide come off or jams if I use Winchester military FMJ FN 115 gr or 147gr Federal HP HST. They seem to fire ok with 124 ammo. I have put 2 or 3000 rounds of the 115 gr without any problems. But when I put the SD round in and try to fire them it happens after about 4-5 round. Do i need to change recoil springs. If so to what, has anyone else had t problems like this. confused:

If it works with non-flat nose FMJ, and 124 gr, that sounds more like the feed ramp having issues with the bullet profile of the Winchester FN FMJ, and the bullet profile and/or overall length of the 147gr HST. With the HST, you're combining a very wide mouth with a long overall length.

Buzz on the Winchester Military FMJ FN is that M1152 spec is at least +P, if not +P+, so I don't know if I'd want to make that my practice ammo. The military contract M17/M18 pistols have slides with more mass than the consumer market P320s to help last longer with this ammo.

I'm not familiar enough with the Equalizer to know what ammunition they typically do or don't have feeding issues with. It's possible that your feed ramp is out of spec.