Most primers have about the same pressures. Cheddite, Win, Fiocchi and Rem. are all about the same, within a hundred or two for pressure. The Federal are usually quite a bit hotter. Crimp depth has a greater effect on pressure. Factory shells have about .050 to .060 and that is what is used for reloading data. Going down to .020 or up to .080 will change pressures by 1 to 2000psi. Paul

Tom Armbrust's tests show higher variation than 100 PSI
http://www.armbrust.acf2.org/primersubs.htm

My statement was too general. Tom has listed more primers than I knew about or generally see for sale. Looking at my IMR handbook, only the Fed 209A primer gives a much higher pressure than the Win 209 or Rem 209P. From the Claybuster wad guide the Cheddite is about the same as Win. I believe the Fiocchi is the same as Win. I couldn't find any load data for some of the primers Tom listed. So yes, there can be more variation and one should check first. Paul

have seen some loads listed bypeople who are very good at ballastic and pressure testing and some of the loads with same primers powder shot and wads hulls etc...would give pressures as much as 1000 difference in pressure..and these loads were loaded up at the same time with identical every thing.... charlie