I have been working on a Spring compressor to sell and this is what it looks like so far.
It's .045 wall Aluminum tubing with 1 1/2 square red maple ends, the screw end is pinned on with 5/16 brass pins and the bottom fixture is also supported with 5/16 in brass pins. The tubes on this one are 24 inches long but I am going to make them a little longer to fit more rifles.
The screw is 7/16 in threaded rod that is tapped into the wood end.
And yes Ken it's plenty strong to do a 1250, I have a hydralic pressure gauge I use to test springs and I put over 250 lbs on it and it didn't break or strip out the threads in the wood.
In the other picture it has a beeman R-7 going back together, and was no problem, with the Nylaron bushing on the end of the screw the spring did not even want to spin as it does with a compressor made with a cut off "C" clamp.
I am still working on the center support for the rifle breach but I need to go to the lumber yard Monday and get a wider chunk of maple. It will have a plastic coated U clamp to hold the reciver from moving around.
I haven't figured out what it will sell for yet till I get costs for the material and machining time, it also will be a kit that you will have to assemble so to keep the cost down.