Originally Posted by Akita
With my HFT ive found that its best to have 775fps the highest it will spit out the 8.44 pellets at the peak of the curve.
I wonder if the stock inletting on them is good as mine has little rough little spikes along the air tube section?
I've have worked on the inletting of both my HFT500 and my Ultimate Sporter. Both actions were very, very tight in the stock when I bought them. It took a lot of time and patience to rub them down. When I was happy with the results, I glued a thin strip of ribbed bicycle inner tube to the front and back of both stocks. Very happy with the results.
I agree that 775fps is the maximum for the HFT500. Mine shoots very consistently between 765 to 775, but starts to spray pellets like a shotgun at anything over that.