Stretching my new HW50S's legs out

Recently I purchased an HW50S in .177 from PA. During the break in phase at 10 yards I used Iron sights at the pellet trap.
I did not enjoy that in low light and knew they wouldn't suffice with my 4 eyes and longer distances, so I bought a BSA 3-9X40 AO Scope from Optics Planet.
I mounted the scope as soon as it arrived and the groups tightened up combined with the seasoning of the barrel.
Took her out to the Conservation Club range on the 4th of July figuring no one would be there. Wrong, a dad was on the 50 shooting his air gun his two chatty 9-11 y/o sons were firing some cheap Chinese bb guns and were happy to be hitting paper at the 25 yard pistol range. Soon though I had the range to myself and this is when we really stretched out the 50s for a true test.

I shot 12 different pellets (10 per pellet) at 10 meters from 7.87 to 10.65 grains. My best groups were with the JSB Diabolo Exact 8.44 gr, H&N Field Target Trophy's at 8.64 gr and the RWS SuperDomes at 8.3 grains. One pellet I will not be using is the JSB Hades 10.34 gr due to loose fit as I lost several during the loading phase when closing the breach. I crushed one pellets skirt during closing and managed to get it out simply by elevating the barrel.
Question: On the H&N Barracuda Green (lead free) at 6.64 gr it states "for PCP only". Is this OK to use on Springers?

My next time out I will be getting out the chrony and then taking her out to 25 yards and maybe 50.
So far I am impressed with the HW50S and I find it a joy to shoot even with the extra left arm strain.
 
On the H&N Barracuda Green (lead free) at 6.64 gr it states "for PCP only". Is this OK to use on Springers?
They shouldn't hurt anything but the 8.44s are probably a better choice. My 50S will eat those and the 7.87s all day.
 
@BanjomanMI76 - Great choice in rifles. Mine is not pellet picky at all in .22. It even shoots CPHP's in a pinch with decent accuracy.

I recommend using two arms to close a springer. My shoulders appreciate it after a four hour shooting session. Plus it brings the cocking mechanism closer to the ears for some german ear candy cocking sounds.