I picked up a new 22" JM Pro today. Mag extension nut was loose, recoil pad was loose, barrel clamp was loose. Action was sluggish returning to battery, compared to our 930 Field/Security Combo. So I fixed the loose stuff on the JM and hoped the sluggishness might iron itself out. It's been raining non stop today but I went out to shoot anyhow. Think i had some rain on the camera iens when I took this. I took an assortment of Univeral #8, Remington and Winchester 0 and 00 buck and some Remington 1 oz slugs. All shells were 2 3/4. It ran the first mag of Universals OK and choked once on the second. High brass buck loads started hanging up just short of being chambered. Slugs required the charging handle be manipulated every shot. The gun shot great with the IC tube installed and made well centered patterns and kept essentially all buckshot pellets on a 12" plate at 25 yards, where it was also easy to put a slug on an old spray paint can. I centered the 12" plate easily from 50 yards and nailed the diamond plate (both shown left of the shotgun) twice from 100 yards, all with slugs. I tore the gun down and discovered burred recoil spring ends and a good burr on the recoil spring plunger. I deburred both and turned a 1/16" bevel on the leading and trailing edges of the plunger. Then I polished the plunger with 1000 grit wet or dry, blew the grit off and gave everything a dousing with CLP. I also put a good dab of automotive anti-seize on the plunger end of the spring before reassembling the recoil system. This took all the sluggishness out of action cycling. The chamber had sharp edges around its circumference so I removed those and polished the chamber itself to 1000 finish. I cleaned the barrel well, reassembled the gun and headed back to the range with a box of Universal and 30 round each of Remington & Winchester 00 Buck & Slugs. 100% function and I ran the gun so hard the rain was steaming off the barrel. This JM is a great shotgun now, but it required way more correction than any new gun should. If a guy who couldn't work on guns bought this, he be shipping it back for Mossberg to correct a bunch of stuff they should have gotten right in the first place. Nobody wants a high dollar 80% kit with a serial number.