Well now ...

I've seen and read several posts and reviews on different pellets about finding the "RIGHT" pellet for you air rifle and truthfully I thought it was just a bunch of hype. Coming from the gun-powder world prior to air-gunning I thought the only issue I would have would be with elevation as I went up or down in pellet weight, soooo, now its time to admit I was wrong.

I now get 1/2 inch groups in my Gamo Magnum .22 with RWS Superdomes 14.5g at 20-yards with open sights using a mono-pod with 60-year-old blurry eyes.

And .. .. ..

I get the same 1/2 inch groups in my Crosman Vantage NP .22 using JSB Match Jumbo RS 13.43g

Anyway, oh well, it cost me a few extra $$$$ in pellets. >>> BUT <<< now it has become more of a pleasure shooting my air-rifles :)


 
Glad you got your gun shooting! I have good luck with jsb exacts and HN FTTs. Also as strange as it is I also have had jsb RS shoot very accurate in even magnum springers as long as it’s under 25 yards. I am not surprised the RSs shoot well in your gamo. I started in airguns moved to benchrest centerfire now back to airguns. On fire arms I’ve had just a small change in grains when reloading have tremendous effects. Lots to play with there, seating depth, grains of powder, type of brass, on and on. With airguns we generally sort pellets so you plink with the deformed ones and target shoot with the good ones. Wash and lube them if you want, lemon pledge. I’m about to test this though by shooting groups of lubed vs non lubed. Are you seating your pellets flush with the breech or do you use a seating tool?
 
Good that you came around and saw the truth. I thought some things sounded crazy early on myself but found the greater portion of the written word to be faithful and true regarding these things. Thought that weighing and roll sorting pellets would not make that much of a difference also but once I started doing it my groups shrank to new lows. So one never knows until they try it.

We would welcome you to the dark side. 😈 The PCP addiction is waiting for you and your $.
 
Glad you got your gun shooting! I have good luck with jsb exacts and HN FTTs. Also as strange as it is I also have had jsb RS shoot very accurate in even magnum springers as long as it’s under 25 yards. I am not surprised the RSs shoot well in your gamo. I started in airguns moved to benchrest centerfire now back to airguns. On fire arms I’ve had just a small change in grains when reloading have tremendous effects. Lots to play with there, seating depth, grains of powder, type of brass, on and on. With airguns we generally sort pellets so you plink with the deformed ones and target shoot with the good ones. Wash and lube them if you want, lemon pledge. I’m about to test this though by shooting groups of lubed vs non lubed. Are you seating your pellets flush with the breech or do you use a seating tool?

I'm seating the pellets by hand flush with the breech
 
The above sampler kits may be helpful but "your" pellet for "your" gun may not be in that supply. Like you, I was involved in PB reloading long before getting really involved with air guns, even though I've had air guns since the 60's. The air gun, and especially PCP world, is a different beast. Being able to do it closer to home is a big advantage for many, myself included. You find lots of good information and opinion here. Hope it all works out for you.
 
Just me but when testing a rifle for the best pellet I always start with a clean barrel and shoot till group tightens up and then until a accuracy drops off. I document number of shots. I clean simply by pulling a tight patch through the barrel saturated with White Lightning followed by a dry patch. I have a rifle pellet combo that shoots lights out for 40 shots and then starts to go south in a hurry but if I pull a patch through it at 30 shots the 31st shot will be dead on. Another rifle takes a few fouling shots and then is good for hundreds of shots. Not always easy to find the perfect combo but that's air gunning I guess.