That is curious. What distance are you shooting? So are they shooting high relative to lead pellets or high relative to less pumps with the same pellet, and you didn't observe any high/low POI with lead pellets?
I was shooting with my Daisy 880 from a rest at 10 yards (not meters). Before that, I'd never had an issue with the rifle using any of probably close to twenty different types, weights and brands of lead pellets; it just didn't seem to be the least bit pellet picky! I was target shooting exactly the same way I do about three to five times a week, but using lead-free pellets exclusively, as I've been doing for at least a couple of months now, with nothing unusual happening until this last session. The pellets in use were all .177 caliber lead-free, including: GTO Predator (domed), H&N Baracuda Green (domed), H&N Field Target Green (domed), and Olympia Match pellets (wadcutter). Oh, and a Crosman alloy/plastic pellet called a Penetrator or something similar (?). Very nice, actually, but they're all gone now except about forty or fifty of the .22 caliber version. All of the pellets named in .177 are mirrored in .22 caliber, except for the Olympia Match I bought to try out (.177 only so far) and those Crosman Plastic/Alloy pellets; in .22 caliber, they are a red-plastic backed/alloy pointy headed combination, instead of the gold plastic/alloy pointy .177 version. Anyway, from the products named above, my particular pellet preferences have turned out to be:
1. GTO Predator -- Best pellet overall in both .177 and .22 caliber, but to me, they're jarringly costly! Much too much for casual plinkin' and target shootin.'
2. H&N Baracuda Green -- Another fine pellet, and much more affordable. This and pellet #3 are almost a toss-up as my go-to, most affordable favorite.
3. Olympia Match .177 -- These shoot quite well, all things considered, but they're not as well made as the others. A few times (less than five out of hundreds), after 'shoving' a tighter-fitting Olympia Match pellet into the breech with the bolt of my Crosman 2100 Classic, they've actually failed to shoot with only three pumps behind them, and I've had to use my 36 inch carbon fiber cleaning rod to push 'em back out. Still about 99.9% fine, so no foul.
4. Crosman alloy/plastic 'penetrators.' -- Basically, these are roughly as accurate (or more so) as those above and they get the very best, furthest penetration into my cardboard-sheet stuffed pellet trap. Unfortunately, like #1, they're also far too costly for casual use.
5. H&N Field Target Green -- I can't really say why, but I just don't like what to me are just a shorter, even-lighter version of the H&N Baracuda Green pellets. I still have about a tin and a half of the .22 caliber and a handful of the .177 caliber pellets left over to use up, after which I'll probably not buy more.
X. I'm very anxious to try out the 'new' H&N Match lead-free pellets I just recently noticed on the Pyramyd Air website, which are the most affordable lead-free pellets available there. I'm about to order four tins in .177 to try 'em out and have pretty high hopes for them, since they're made by H&N, which in my experience typically means higher quality and excellent accuracy.
Okay... My collection is made up primarily of variable pump pneumatics, my favorite type, with the remainder one single nitro piston (I don't like it, or any other gas- or spring- piston break barrel I've ever shot) and the rest powered by CO2. In target shooting since I went lead-free, I'd never noticed anything unusual until that day. This time, I'd been shooting with my Crosman P1377 'carbine' (pistol and shoulder stock) and Benjamin 397s (two of the three .177 pumper airguns with which I get the very best accuracy using open sights (the third being my Winchester 1977XS)), using my usual three or four pumps of power, when I decided to switch over to my all-but-equally accurate and oldest air rifle, the Daisy 880.
I'd been using the Olympia Match pellets for the most part that day, but when I picked up my 880, I switched over to my least-favorite H&N Field Target Green pellets to use up, which I've used before in nearly all of my disparate .177 pumpers, with the usual three or four pumps, without noticing anything weird. For some reason I don't remember, I put about seven pumps in for my next shot and even though I didn't do anything different while aiming, I totally missed (by a good one-half to three-quarters of an inch)! That was a surprise, as I was expecting another bulls-eye. Okay, I tried again, with my usual four pumps, and as expected, I'm right on, as are the rest of the three and four pump powered shots that follow. What the $%!? I remembered I'd used more pumps when I missed, so I increased the number of pumps again, and every other same-in-all-regards-but-the-number-of-pumps-used shot produced a hit that was off by about the same distance high (and maybe just a skosh left). Up to four pumps: just fine. Five pumps and above: high every time. Too strange! I VERY carefully examined the Daisy, thinking maybe there was some defect I'd not noticed before, and I tried all my other pellets again as well, all of which were roughly equally accurate, regardless of the power behind them. Switched back to the H&N FTG pellets, and with business as usual, everything was fine, but with more power than usual, they were off high (and maybe a skosh left)!
That's it, as far as I can remember. My Daisy 880 (the all black, 5880 version shipping with the Powerline 880 Kit) has no trouble with anything else I have or have had, excepting only that one remaining tin of H&N Field Target Green pellets and then only with power levels higher than four pumps. I guess it doesn't like the light weight (it is lighter than any of the others). That's my story and I'm sticking with it.
