I started doing this a couple weeks ago. I am using a feeler gauge to adjust my RCBS seating die. Now this is the regular die without the micrometer. So this is what I am doing.

I set a bullet about .010 shorter than my coal goal and tight the die nut allen screw to set the depth.

Depending on the bullet quality I will back out the die until I can insert a feeler gauge measuring a bit over the .010 difference. Now, some bullets you can just go .002 over the .010, some cheaper bullets you will have to seat longer. This is because the cheaper bullets ogive dimension is not going to be as close tolerance as the better quality bullets. That will give you different bullet seating numbers. You might have to play with that, find the average and note it down.

Now I start seating bullets taking measurement every now and then to make sure the bullets are seating whiting the tolerance I want or longer than what they are supposed to, it is easy to fix a bullet that is seated long as short seated bullets might present a problem as you will have to pull them out of the shell which probably make your bullets not be seating in the brass as tight as a bullet that have not been pull. If the bullet measures right I put it on the tray or box but if it is longer that the tolerance I want I put then in a chart. Once I am done seating all the bullets I check the ones I did not check previously and also either put them in the ok/ready tray/box or seat them on top of the chart according to the measurement. In this case I am looking for 2.700 +- .001

Measuring bullet:


Chart(ignore the decimal point, i now it is .00X but this is a multiuse chart) with the bullet that is .006" longer:


Once I have all the bullets measured I will start adjusting the die to get to the right size.
In my actual example I use .028 as the start gauge. since this bullet is .006 longer than my 2.700 I need to adjust for that difference.
.028 (initial seating gauge) - .006(difference between 2.706(actual coal) and 2.700(desired coal)) =.022, I always like to substract .001 from the result as it tend to give me a better average seating size... So I would end up using a .021" gauge

Gauge changed from .028 to .021. Keep the location of the gauge constant. I actually have it marked down with marker where is the gauges supposed to lay... Tight the die, not too hard, also be constant on that.


Now I have bullet seated to the desired coal of 2.700 +-.001.



In my case I use that same seating die to reload 4 types bullets so I have to find a happy medium when setting the die seating depth nut so that will work for all bullets. So far it is working for me...


Thanks for your time, if the Spanglish is too thick let me know, I will try to clean it up. Hope this helps someone.