Large Psitol Primers vs. Magnum Pistol Primers

[Jack1951]

Does anyone have data on the difference in velocity when using large pistol primers and magnum pistol primers for the same powder, charge, bullet, crimp and COAL?

[GrumpyOne]

Typically, with small pistol and small pistol magnum primers, you gain about 10 fps with the magnum primers. I wouls expect similar results from large pistol and large pistol magnum...

[nwhpfan]

I got no difference between CCI 300 and 350 using 3.8 Clays and 230 coated bullets. Feel, chrono, etc. I wouldn't normally buy 350's, but somebody gave me 1k so I shot them up.

Edited March 28, 2016 by nwhpfan

[zzt]

It really depends on the powder used. I only use CCI 300 (std) and WLP (std/magnum).

For my bullseye load using N310 and 200 LSWC, I get a 29fps difference with WLP being faster.

Same load using e3 powder, the CCI is faster than the WLP by 20fps.

Clay Dot, the WLP is faster by 16fps.

For my Major loads using S1000, the WLP is faster than the CCI 300 by 4pfs.

There does not seem to any rhyme or reason to it.