I agree, not a fan of the lead sled. Loaned a $3500 custom 270 to a guy about 10 years ago and he took it home and put it in a lead sled to check the zero he said. This gun was a Remington 700 Custom Shop AWR built in the late 90's and shot 1/2 moa with factory ammo when I loaned it to him to try out. Had a leupold 30mm VX 3 with a German #1, very hard to find. Got it back from him and he said he could not make it shoot less than 2 inches. Got it home and took it to the range to shoot it and sure enough it would no longer group consistently. Took it apart and the stock was cracked just in front of the trigger guard. Called to ask him what happened and he said nothing that the only thing he did was strap it in his lead sled and shoot it. $650 and a month later it was fixed. I don't shoot nor do I allow any of my rifles to be shot from a lead sled. Be very careful if you do, as has already been said all that energy has to go somewhere! A good front rest or bag and an equally good rear bag and support with proper form (being aligned properly behind the rifle), good trigger control and breathing (no drive by shooting) and that rifle will shoot as good as it ever will.
Stories like this literally had me print the return label last night before the lead sled even delivered. I'm not putting my Remington 700 Sendero FS 7mm STW with Leupold Mark 5HD scope in a vise that is going to crack my stock and damage my scope and rings.