Hi, the conjecture about which percussion cap make is best goes on and on. I did a little testing to determine if there was a dimes worth of difference between CCI and Remington. All my Pietta 1858 Remingtons have Wolff reduced power springs in them and reliably fire CCI #10 caps. However, I have found that reduced power springs in the 1851 and 1860 Colts problematic for reliable ignition using CCI #10 caps (I never before tried the Remington caps in these revolvers). Mike made a video where he also had problems with the 1851 using reduced power springs, see:
While Mike shows a few misfires on the first hit, emails from him show that the second hammer hit will then fire the cap, also my experience.
The marginal ignition of the 1851 Colt with reduced power hammer spring seemed a good test platform. I have both old and new CCI and Remington Caps to test using my Pietta 1851. Old and new are relative terms, old is ~20+yrs, new <1yr. These are my cap results (six caps loaded per test, no chamber powder):
New CCI #10
Bare primer mix.
Only 2 out of 6 caps fired on the first hammer strike.
The remaining 4 caps fired on the second hammer strike.
New Remington #10
Bare primer mix.
All 6 caps fired on the first hammer strike.
New Remington #11
Bare primer mix.
All 6 caps fired on the first hammer strike.
Caps had a tendency to fall off cones.
Old CCI #11
Bare primer mix.
All 6 caps fired on the first hammer strike.
Old Remington #11
Metal foil covers primer mix.
5 caps fired on the first hammer strike.
1 cap wouldn't fire even after many hammer strikes.
Something to note is that the new CCI when they fire are very intense, the cap fragments. The new Remington Caps are indeed hotter than the old Remington caps, but it's more like a burning instead of explosion. It's clear to me that #10 caps fit the Piettas much better than #11 caps.
This testing is personally useful to me in that I now know that if I use Remington #10 caps in my reduced power spring Colts with cap and ball, they will fire reliably. I hope you also find this cap testing useful.
Regards,
Richard