Pressures with PPB's

[jpuke]

Are pressures any higher with ppb's?   My guess is that the pressures would be either equal to or only a slight bit higher than those in cast bullet loads of the same weight.  Has anyone else ever wondered about this?  I'm looking to load a 530 gr PPB in a Marlin 1895 (RCBS mould, says it casts 500 but it came out a bit heavier) around 1200-1300fps.

[JCP]

I haven't done any tests but I read somewhere that jacketed creates the highest pressure with lead coming second and paper patch  third. That doesn't include hard cast which can produce higher than jacketed I think. Some one here will know a lot more than I.

[JDL in NC]

I've found by testing using a "Pressure Trace" with a strain-gage installed on a Encore barrel that for a given load the pp bullet usually produces less pressure, probably due to less friction.  I also found that powders (IMR 3031) that burn clean with jacketed bullets leave residue (unburned granules) in the barrel, probably due again to the decrease in friction between barrel and bullet.  I found that H4895, H322 and H benchmark are cleaner burning in my 45/70's using a 395 gr pp bullet.

I think recoil will probably be the deciding factor as to a max load, using a bullet over 500 grs in a Marlin 1895.  I know the one I had, punished me pretty bad!!

JD