Im sorry if I have mislead you but I dont use the 155 berrys only the 180rs berrys. I was pointing out that the col has an effect on the pressure. If the col listed for jacketed will cycle BY HAND with the berrys and if it were ME then I would start at 4.8 with that col (I did not cross check the charge you posted) just to be extra safe. If you have to go shorter than the listed col you may want to drop the charge a little more. After the initial function test you should have an idea about where to go from there. Dont rely on primers for pressure signs but measure the area at the case web for expansion. Also dont get in a hurry and make big changes in powder charge, just work the load up slowly until you get the desired reliability and point of aim/ point of impact relationship (this may not always be possiable for the combination you are using). And since you posted you are loading for a glock Im sure you have heard that if a reload even gets into the same room as a glock it will immediately blow up and as a result your truck will get poor gas mileage. That is not true but what it will at least blow up if you make poor decisions and are sloppy with your reloading. I am also sure you know about the glock bulge. My reloads dont get to the point that the case buldges and I have almost 100% reliability other than a few primers not seated fully. Let me know how it works out.