I ran into the cross over point a few time with a Winchester 7MM Mag with 140 grain bullets. I think we were using H450. I also have run into points with slow burning powder where velocities rise to a certain point then began to fall off. I had a 280 Remington at the time as well. I could acheive higher velocity with the 280 than I could the 7 mag with the same bullet. Sometimes things just don,t work. I will keep trying but the most important thing as someone above said Safty first this may just be one of those rare cases where I am stuck with one bullet bullet weight with that rifle. It is a 69.00 dollar rifle when I got it. I put another 100.00 in it in the form of a timney trigger and some machine work to change the bolt handle and drill and tap for scope. My cousin shot an elk and a moose with it and I have shot about 25 deer with it. All with the 140 grain Hornady bullet. The moose was shot with a hornady 160 grain round nose. I would have to find my old chronograph book to see what we had for velocity on that bullet I keep a close record of all loads chronograghed over the years and the data on the loads. Its a valuable reference book. I filled one book and retirted it but its still here somewhere. I have probably got readings on several hundred rifles and pistols. I used to go to the range every Saturday and everyone who had loads to test and didn,t have a chronograph would misteriously show up. My first one used those old paper screens which were not cheap or easy to get. The 17 remingtons used to shoot between the little lines on the screen and fail on one end or the other. Thanks.