Usually, (maybe always) it’s Gamo advertising these incredible speeds. It’s marketing and it sells guns to those that don’t know any better. And yes, I think they do obtain those speeds but with incredibly light pellets and it will be pure luck if you ever hit your target. Pellets start to lose their accuracy at about 900fps so when they start advertising 1100+ fps you really need to question their quality because they are selling you on fps and that’s pretty worthless in actual use. I’ve noticed some Gamo ads recently that are 1400 fps! Not only inaccurate but also very hard on the gun as the piston is slamming to a stop because the pellet isn’t heavy enough to slow it down properly. PCP’s are a different animal and avid air gunners won’t be bs’d with or sold on velocity.
I have light 7-8gr pellets that shoot really well in my FWB 124 Springer, maybe around 3/4” at 30 yards. Max velocity is about 800 fps. If I shoot the same pellets in my Benjamin Marauder (PCP), 30 yards groups will open up to 1.5” and this rifle is more accurate than the FWB. If I remember correctly, MV on these was over 900 fps which is just too fast for these light pellets. 10.34 gr JSB pellets work well in both guns.
I also have an RWS 48 springer but I haven’t found an suitable pellet for it yet. I have some coming tomorrow that are 11+ and 13+gr that I’m anxious to try in it. This is a very powerful springer and I’m hoping these heavy pellets will tame it down a little and give me the accuracy I think it’s capable of. This is a fixed barrel and it should shoot much better than it does. Of course I’m sacrificing velocity but it will be worth it.
One of the pellets I used to shoot all the time in my FWB 124 and it was always very accurate, the most accurate I’m thinking. Boxes didn’t have the weights on them and I never weighed them. They were pointed (cool) and accurate, that’s all I knew. They are probably more accurate because of the weight, weighing about 11.5 grains. I have two boxes of those coming, I’m certain they’ll shoot well and an extra box for nostalgia.
I still have a partial box of 6.1grain Prometheous pellets. These have a plastic skirt flared on both ends and a ballistic tip like insert that I‘m guessing is made out of zinc as it‘s quite hard. Supposed to be really fast hunting pellets. So… we hunted with them one night, shooting pigeons in a barn. I hit the first couple but wasn’t anchoring them. Then the misses started and we were shooting 30-60ft and couldn’t touch a pigeon. I looked through the barrel and I could hardly see through it, The plastic skirts were being shredded by the 12 groove rifling and I had a bad case of “plasticing“. Shot some lead pellets through it to clean it and went back to hitting the pigeons again and never used those pellets again. I need to post some pictures of these pellets and guns…