You'll have to see what happens but I suspect you will need to decrease the regulator but it is not very hard. My Bullshark in 22 prefers AEA 18.3 grain and sends them about 870 fps. It will also shoot Crossman domed accurately at about 925 fps, however. I could bring the velocity down with the hammer spring but it is not as accurate and the first shot at the start of the day would be much lower in velocity. They like to be tuned about 3% under the peak velocity. My P35-22 is very similar and prefers 21-22 grain pellets which it only gets up to about 820 fps and less in cold weather. But it's accurate - two 200s on the 30 yard challenge (Bullshark has 1).
If you are lucky you can access the regulator from the gauge end of the airtube. After degassing you remove the big nut the gauge is on with the thing that looks like a tube that will come with the gun. At the other end of the tube you will see the lock nut (12mm) and slot headed adjustment screw for the regulator. You need about a 18 inch screwdriver and extension for a socket. The luck part is whether the O-rings are set enough you can loosen the lock nut and then it moves pretty freely on the adjustment screw so it doesn't change the adjustment when you turn it to lock in your setting. To decrease you will want to turn clockwise, no more than 1/4 turn would be my suggestion. Once the screw is turned and secured you just put it back together and air it up. If you have to remove the regulator it is not that bad but you have to remove the air tube from the gun. If you loosen the two 3mm allen head screws that clamp the barrel to the air tube you can just unscrew the airtube from the action. The stock screws will need to be loosened a little but it's actually better to leave the action in the stock. One of the potential complications is getting the clamps mispositioned causing the gun to not cock or the safety to not work. It is not very hard to fix but leaving the gun largely still in the stock helps keep things in the right place. If the air tube is out you just unscrew the nut at the back of the airtube and the regulator may come with it. If not, you have to remove the other nut and push it out, a dowel is a good tool to use. I've started using digital calipers to measure the overall length of the regulator to help anticipate the setting. You can only do that if you remove the regulator.
I always relax the little coil spring on the trigger mechanism to lower the first and second stage pull weight of the trigger. You have to take the stock off but all you have to do is loosen a tiny grub screw to relax the spring. The stock screws are 4mm, the hammer adjustment is a 5mm allen head.
