--.22 Pros--
- Accurate
- Reliable
- 10 shot magazine
- Quick reload via new mag
- Usually good sights
- Can remain in a "loaded" condition for years if necessary.
--.22 Cons--
- low relative power factor,,fatal to be sure but poor stopping even w/multiple hits. My half-fast guesstimate is 3 shots min/ 5 to 10 shots max per "target" YMMV but before you decide take a look at the energy figures.
- Small caliber means exacting placement of shots,,,"head shot" doesn't cut it,,,think in terms of occular or nasal cavity (people wonder why I shoot at pennies as targets,,,well,,there you have it,,a penny is about the size of the eyeball or the nostrils.)
--Derringer pro(s)-
- Large caliber
--Derringer cons--
- Too many to list,,,,just shoot one and you'll figure them out PDQ.
--Cap and Ball Pros--
- Excellent stopping power. Pretty much on the same power level as the .45acp.
- Mulitiple shots. (If the smoke is in your way, you're likley to be dead anyhow,,,,move to cover, move to cover, move to cover,,don't just stand there. Even at that, the smoke isn't quite as bad as is made out.)
- Smoke. Yes, it can obscure YOUR movements as you,,,move to cover, move to cover etc.
- Accpetable accuracy at HD ranges.
- COM shots are possible due to caliber/power level.
-- Cap and Ball Cons --
- Smoke. Yeah, it does smoke more than the others,,, and it can obscure the target.
- Prone to jamming from bits of the percussion cap falling into the works. Mine did that quite a bit.
- Prone to misfires from the grease used to seal the chamber mouths seeping into to chambers. Criso works fine at the range and in the field. It melts pretty easy into a liquid if you keep the thing too close to your body. Using round balls and a felt pad can eliminate the need to grease the chamber mouths, but you pay for it with a less effective bullet.(sumptin 'bout no free lunch)
- Slow to reload.
- Limited time for remaining loaded. BP and it's substitutes are hydroscopic. They'll pull moisture out of the air given half a chance. Keeping a cap and ball revolver loaded and ready to go is pretty much a short term affair....personally I don't think I'd keep them that way for more than a week.
(Last but not least)
- Price. A good quality BP revolver, like the Ruger is expensive. Ruger lists them for ~$500.00. The Italian made ones aren't made for long term use/abuse. *and yes, I own 2 of the Italian ones.
- Safety--- BP is nasty stuff. No, let me rephrase that,,,BP is REALLY nasty stuff. Most users of modern firearms and ammunition don't really understand how dangerous BP can be. The common ammunition/smokeless powder practices I see and read about both on-line and in the real world would be extremely iffy using BP.
Bottom line,,,I'd pick the .22 overall. As always, YMMV.