I also wanted to make a spring compressor and followed all of the links and watched all of the U-Tube videos and decided that a simple sash clamp would work just as well for me and it did not have to be expensive!

A cheap Silverline sash clamp was bought from Amazon to use as a spring compressor, and it works well on every type of spring air rifle I have stripped to date.

A piece of scrap soft wood (or ply) at each end prevents any risk of marking to the rifle barrel and end caps, and an old towel placed over the base rail of the clamp also prevents any marking of the barrels etc.

Not exactly a high tech solution, but it works very well and it did not cost a fortune or take any time to construct.

Free "next day" delivery and the fact that it can still be used for other jobs (as a sash clamp) made it a "no brainer" for me and has been one of the best buys I have made.

If (like me) you want to work on underlever air rifles, make sure you buy one that is long enough to work with the barrel still on the rifle. The adjustable end stop on the sash clamp makes it easy to shorten for work on break-barrel and shorter rifles too, and can even be adjusted to be short enough for use on spring powered air pistols such as a couple of Original Model 5's that needed some work recently.