Don't know if these fit the 2.0 or not. You'd have to contact them to find out. A 5" barrel will be aftermarket only in 357 Sig, as S&W never made a 5" M&P in that caliber, so no factory 5" barrels. At least I don't think they ever made one. I know they made the regular service models in 357 Sig (4.25" barrel), but they discontinued them.
Honestly, I'd just stick with 40 S&W. With a 5" barrel, an Underwood 135 grain JHP will be over 1400 fps. Personally, I'd go with a little heavier bullet for sectional density and run a 165 grain JHP. An Underwood 165 grain is listed at 1200 fps/528 ft. lbs, and that's probably with a 4.25" barrel. Should be really thumping out of a 5" barrel. For woods use, a 40 S&W 200 grain flat nose hard cast out of a 5" barrel should bust through anything this side of the Rockies.
M&P L/Pro .357Sig (5.01 OAL) for 1.0 & 2.0 – KKM
kkmprecision.com
Honestly, I'd just stick with 40 S&W. With a 5" barrel, an Underwood 135 grain JHP will be over 1400 fps. Personally, I'd go with a little heavier bullet for sectional density and run a 165 grain JHP. An Underwood 165 grain is listed at 1200 fps/528 ft. lbs, and that's probably with a 4.25" barrel. Should be really thumping out of a 5" barrel. For woods use, a 40 S&W 200 grain flat nose hard cast out of a 5" barrel should bust through anything this side of the Rockies.