There has been so much confusion and misinformation regarding the use of Skip Shims with FL dies in one of the recent threads that I created this post to hopefully clear things up.
First, I do not have any financial interest in Skip Shims. I am not promoting their use exclusive of other methods. Yes, I've used them for many years because I found them to be the easiest, cheapest, most precise way for ME to make FL sizing die adjustments.
Second, they are not feeler gauges. The are designed specifically for reloading and fit under the lock ring of the die for use with conventional presses like RCBS Redding, Lyman, etc. (Visit Brownell or Sinclair's web sites for a description)
Thirdly, there are other methods for making sizing adjustments to the FL die that are used by others that work equally or better for them. For example, competition shell holders, Whidden Click FL Dies, or just manually adjusting the FL die to obtain the desire sizing. They all can work!
Fourth, if you set up your FL die properly with the shims, you can change the amount of bump simply by replacing the shim. There are different methods to set up the FL die with them. For me, setting up with the .010" work better for ME since it gives me a wide range of bump options by using one of the thinner shims in the set which range from .008 down to .003. Set up this way, the shell holder is always in contact with the die. You never have to change the lock ring of the die to make a sizing adjustment.
Fifth, in order to establish the appropriate shim to obtain the sizing you want, you must use a bump gauge and measure the fire case at the datum line and compare that measurement to that of the sized case datum line. This only works best if you have a group of cases dedicated to a specific rifle and rotate the use of the cases, so they receive the same number of firings and sizing's.
Sixth, as with any method, virgin cases should be first fire formed to the rifle chamber before pushing back the shoulder and then only if needed for adequate chambering. I have discovered, that with certain rifles / brand of cases, often a zero bump is all that is needed. I suspect this is due to the fact that the FL die also sizes the radial dimension of the case which is often the culprit in creating chambering difficulty.
Conclusion: Are they better than other methods? No - they are just another way to "skin the cat" but work best for me.
First, I do not have any financial interest in Skip Shims. I am not promoting their use exclusive of other methods. Yes, I've used them for many years because I found them to be the easiest, cheapest, most precise way for ME to make FL sizing die adjustments.
Second, they are not feeler gauges. The are designed specifically for reloading and fit under the lock ring of the die for use with conventional presses like RCBS Redding, Lyman, etc. (Visit Brownell or Sinclair's web sites for a description)
Thirdly, there are other methods for making sizing adjustments to the FL die that are used by others that work equally or better for them. For example, competition shell holders, Whidden Click FL Dies, or just manually adjusting the FL die to obtain the desire sizing. They all can work!
Fourth, if you set up your FL die properly with the shims, you can change the amount of bump simply by replacing the shim. There are different methods to set up the FL die with them. For me, setting up with the .010" work better for ME since it gives me a wide range of bump options by using one of the thinner shims in the set which range from .008 down to .003. Set up this way, the shell holder is always in contact with the die. You never have to change the lock ring of the die to make a sizing adjustment.
Fifth, in order to establish the appropriate shim to obtain the sizing you want, you must use a bump gauge and measure the fire case at the datum line and compare that measurement to that of the sized case datum line. This only works best if you have a group of cases dedicated to a specific rifle and rotate the use of the cases, so they receive the same number of firings and sizing's.
Sixth, as with any method, virgin cases should be first fire formed to the rifle chamber before pushing back the shoulder and then only if needed for adequate chambering. I have discovered, that with certain rifles / brand of cases, often a zero bump is all that is needed. I suspect this is due to the fact that the FL die also sizes the radial dimension of the case which is often the culprit in creating chambering difficulty.
Conclusion: Are they better than other methods? No - they are just another way to "skin the cat" but work best for me.
