Quote:
Originally Posted by red-beard
Interesting thought.
Using Ballistics by the inch, and comparing similar loads to my carry of regular FMJ (for .380, expanding ammo is pointless). I use Speer gold dots 124 gr in my BHP. I'd never run +P in the Colt 1908.
Assuming a 3" barrel for the 911 and 4" for the Colt 1908
.380 - 95 gr. FMJ, using Winchester 95 gr PDX1 as similar
9mm - 124 gr speed gold dot
.380 4" barrel = 966 fps at 195 ft-lbf energy
9mm 3" barrel = 1108 fps at 338 ft-lbf energy
For comparison, out of BHP, the gold dot will be:
9mm 5" barrel = 1259 fps @ 437 ft-lbf
So your point on the reduced performance is valid (3" vs 5" barrel), but the performance of the 9mm in a 3" barrel is still ~50% more energy than the .380
With the Colt Defender 3"
Federal Hydrashock 230gr = 787 fps @ 316 ft-lbf
Corbon 165gr +P = 1050 fps @ 404 ft-lbf
For comparison, Using a 5" 1911A1
Federal Hydrashock 230gr = 895 fps @ 409 ft-lbf
Corbon 165gr +P = 1238 fps @ 562 ft-lbf
Again, at the speed/energy levels, running expanding bullets out of the 3" Colt Defender might be problematic
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Again, you really need to chronograph the loads you are going to shoot out of the guns you will be using. Factory ballistics charts are all well and good, but you might be surprised just how far off they can be from the actual performance delivered in
your guns. I've seen some fall darn near 200 fps short of the manufacturer's published claims. Some use real guns in their testing, some use pressure barrels. Some actually test different barrel lengths, but most interpolate for the lengths they did not test. If I were ostensibly "betting my life" on something, I would sure want to check for myself. Especially since I have found such wild variation from published data through said testing.