Thank you everyone for the input. I do feel this rifle performs very well out of the box, but I also feel there is room for improvement. I know I will install a piston sleeve at some point. I dont own an machining equipment so I will need to wait on a spring guide, at least until tone comes available as an aftermarket option. If anyone has suggestions for me to consider please feel free to fill me in.
I do intend to put a Hawke scope I have on it as well but not certain of the mounts to use as there seems to be an issue with slipping with this in mind any ideas or options a appreciated as well.
My goal for this rifle is to make it one my sons will want to have long after I am gone which will be a long time from now.
Following ChuckHunter's lead, I also purchased a custom PG1 kit from Tom at Vortek. Take a look at this thread for some Sport-tune options:
Factory spring is .142 wire and the kit from Tom is .148 wire. A little stiffer but fits the piston better than the factory spring! I did polish the end that goes in the piston and didn't use any washers! But I'm happy where the power ended up! Snappy shot cycle kinda reminds me of a HW35! Did...
www.airgunnation.com
Need to finish the story on that thread, but to cut to the chase I found all of the following to work well in the Sport:
1) Custom PG1 kit from Vortek (see other thread for ordering specifics, and keep in mind Tom has only made a handful of these to my knowledge so you won't find this on his website)
2) HW80 FAC OEM Spring (purchased mine from CountryStore but many places carry this spring). It's a thicker spring, 3.8mm vs. 3.58mm for the FWB factory spring (these dimensions vary a little bit along the length of the spring and from spring to spring, so don't take these two numbers as gospel). Because of this, I needed to cut it down, which I did by following Kevin LaRose's technique in his FWB Sport rebuild video (Pellets and Pistons YouTube channel). With no coils removed, 8.2g RWS R10 Match's shot at 17FPE, way too high. With 2 coils removed, 14.7FPE. With 3 coils removed, 14.4FPE which is where I like it. Mated with this spring is a delrin "HW80 Titan XL Rear Guide" from CountryStore. This guide (sample of one!!) fit my HW80 OEM spring perfectly. This is the setup I'm currently shooting with. The HW80 rear guide flange is larger than the Sport's, so it needs to be sanded down to seat properly in the trigger block, no big deal.
3) Titan XS No. 2 Spring + Titan XL Rear Guide, both from CountryStore (Titan spring can be found from many places). I don't know what's different about these titan springs, but man are they strong. This spring is also around 3.8mm wire diameter, and longer than the HW80 spring. Barely fitting the uncut spring in the gun, it shot at 17.5FPE, and kicked like a Kentucky mule. Removed 2 coils, only dropped to 17FPE - again, because it's simply too long so coils were still in compression. Removed 2 more coils (4 total), and it dropped to 15.4FPE. I haven't finished cutting this spring down, but expect with 1-2 more coils cut it will perform similarly to the HW80 FAC OEM spring. As with that spring, the Titan XL Rear Guide fit the Titan XS spring well.
4) TbT HW80 Maxi Kit. Same idea as the ones above - sand down the guide's flange to seat in the Sport's trigger block, cut down the spring as needed (it's thick like the HW80 OEM spring), and Bob's ur Uncle. I haven't completed this task yet with this kit, but have high confidence it will work just as well as the others.
5) Factory OEM spring plus custom rear guide. Fabricating a custom rear guide to fit the OEM spring led to a great shot cycle, but underpowered compared to what Kevin and others have reported. Not sure if my gun was a dud or what, but when new I couldn't get more than about 13FPE with any pellet, while others were reporting 14+FPE even after cutting down coils (see Kevin's data in his video as one example). This was the original reason I embarked on this journey to see what other solutions might work.
Thanks to ChuckHunter's posts, we all learned that the HW80 30mm Piston Seals are literally a perfect fit in the Sport. I upgraded the sloppy OEM seal, which I literally fipped off the end of the piston with my finger nail, to a Vortek 30mm VacSeal and improved velocity right off the bat - with no sanding/fitting needed. May have gotten lucky, but I love that seal. This info led to the epiphany that other HW80 components likely also work, i.e., spring and rear guide.
Re: piston sleeve, I tried out the .003" HW80 steel pre-cut sleeve that CountryStore sells, and it fit quite well in the Sport's piston, although I would recommend cutting down the width by about 3-4mm to prevent it from slightly overlapping itself when inserted. I was worried the slightly thicker HW80 wire might cause interference inside the piston, but so far the sleeve looks perfect and there's no "rub" or noise at all when cocking the gun.
Overall, I'm quite happy with the HW80 spring - it's stronger so can be shorter. This makes the cocking cycle nice and easy, like the factory OEM spring, but with more power - at least in my gun. Would have preferred to keep the FWB OEM spring in the gun, but I just can't get to 14FPE with it. I've seen other data for this gun down at 12FPE after tuning - with a sublime shot cycle described. However, I already have FWB 124's that shoot 13FPE with great shot cycle, and I wasn't interested in a FWB Sport with larger power plant that shoots with even lower energy than its predecessor. There's no free lunch here, I'm likely sacrificing some accuracy for the higher power. Also this is limited data, so consistency over time is another unknown with these alternate builds.
As a 44-year FWB owner (FWB 124's, FWB 300's, FWB 150), I already knew this gun would be deadly accurate. FWB has some kind of magic machine in their factory, I dunno but whatever they do is world class. This gun is no exception. I also greatly appreciate how light these guns are, so much easier to handle than other magnums - and yes, this gun w/ 30mm power plant is certainly in that class; as noted it can easily generate up to 17+FPE. Just purchased an HW97KT, and am laughing to myself every time I pick it up. Shoots with similar energy, but feels like I'm pulling a boot off the bottom of the ocean to lift it. Gorgeous kit though, and so well supported. That's the Achilles heel of the Sport - not many sold (AoA guesstimated 10-15K when I asked), so it's really hard to find any info/reviews/aftermarket accessories.
