Originally Posted by delta13soultaker
For a .22 LR bullet to achieve clearly better terminal ballistics than a .38 Spl, the .22 bullet will need to be moving way faster, say another 600-1,000 fps, and then would need a better built bullet than anything in a .22 rimfire to hold its mass inside the tissues it must penetrate.
Delta, I'm going with purely comparative numbers and not converting to ft-lbs, but a .38 spl traveling at 850 fps with a weight of 125 gr. is going to produce only ~3% more energy than a 32 gr. .22 traveling at 1650 fps from a 20" barrel. For a 40 gr. .22 round traveling at 1250 fps. the energy difference is much more, at ~30% less energy for the .22. I get this by the formula that Energy is proportional to Mass times Velocity Squared (E=1/2 M*V^2).
You're absolutely right on that the .38 has more frontal area and will have more momentum for penetration and less fragmentation on impact which make it superior in most cases. I just thought it was really interesting how close the actual energies are for a high-quality hyper-velocity .22 round. I'm not trying to dispute your post because I believe you're still technically right.
I just think about how quickly I can follow-up on a .22 shot from a semi-auto vs. a .38 shot from a J-frame Airweight and I get right back at Josh's question about which would be realistically better for me?... Hmmm...
Easy answer though... If in the situation where one can wield a long gun, I take the 12 gauge with 00 buck. If in the situation where the .22 might be frowned upon by my side, the .38 would fit nicely in a waistband or pocket. In either case, the .22 loses...