Originally Posted by jfseaman
Is 'sticky bolt' caused when the pressures of the firing process cause some elastic stretch in the chamber such that the brass goes beyond chamber dimensions and when the chamber contracts the brass is captured?
Yes, this is true(beyond unfired chamber dimensions), and way overlooked by reloaders, and by those building custom guns lately. Brass changing beyond 1thou yields, and does not springback fully to original dimension, while a chamber certainly does return to original.
There a 3 ways to head it off from the git-go.
-Choose a modern or improved cartridge design.
-Provide sufficient barrel steel around your particular chamber & load.
-Measure brass in-hand before filling out a reamer print, and go no more than 1thou over webline(.200" forward of extraction groove). In fact, you can go 1thou over with every dimension with your reamer w/resp to new in-hand brass. Order the ~$100 reamer, and have your barrel and seating dies finished to match brass that you will produce with fireforming.
If you do these things, you will never need to FL size a piece of brass, because the brass will forever springback this amount. It won't need much in sizing, trimming, annealing, etc.
And, every time you read someone implying a 'requirement' to FL size, recognize that they did not address this issue that suddenly spewed from your brain. They made choices that put them where they are.