We finally got some decent weather and I was able to get out today and chronograph a bunch of loads out of my rechambered 360J. For comparison I also used a S&W 637, a Taurus 905 (the Instant Backup model with a short, 9mm length cylinder), a Beretta 8000D Cougar, and a Rock Island Armory .38 Super. All of the results were enlightening, some surprising, and some a bit disappointing. I didn't get anywhere near the velocities out of the 360J that I thought I would but I was able to see the reason why, which I'll get to later. I was shocked by the velocities out of the 905, they were almost equal to the Beretta and easily surpassed the 360J. Also, it was clear to me that what I thought about ammo, based on what I've read, was incorrect. The advantages and disadvantages of barrel length, chamber dimensions, and pressures were obvious.
So, here's the numbers and I'll discuss my thoughts on the results below:
Now, what was clear to me while shooting all of these rounds is that the 9x23 chambering in these conversions is a compromise that doesn't fit anything well, including the 9x23. Since you're starting out with a chamber that is cut for the .38spl (a straight .379"diameter for the entire 1.096" depth) when you recut the chamber for 9x23 (.392" tapering down to .381", but only to a depth of about .870") you end up with gaps at different points in the chamber depending on what caliber you're loading it with. IMO, that is why I got the reduced velocities out of the 360J, I was losing pressure in the chambers and it was evidenced by the soot on the outside of the cartridge cases and some case bulging with some hotter rounds.
So, since I can't think of all of the questions that might be asked, I'll give you a couple of more of my thoughts and then answer or discuss any of your questions or observations:
a. Obviously the 9mm out of a properly chambered snubby is pretty hot compared to the .38spl (Taurus 905 velocities vs S&W 637). IMO, the difference in recoil between the two was negligible, the 9mm is nothing like a .357mag.
b. Given the loss of velocity with the converted cylinder it's a matter of personal opinion if the expense is worth the 150fps difference between the .38spl+P and the hottest 9mm load I had.
c. The current .38 Super loads aren't so super. In fact the velocities I got out of the 1911 weren't much more than you'd expect from the .38acp it was supposed to replace. It does make me want to check out the Corbon loads, though.
d. Barrel length makes a difference with hotter loads, more room for powder to burn = more pressure = more velocity, as evidenced by the Federal 9BPLE numbers out of the Beretta (3.6" barrel) and the HK (4.41" barrel).
e. The cylinder/barrel gap doesn't mean that much. In spite of being a revolver with a short 1.75" barrel, the Taurus 905 velocities were within about 3.5% of the Beretta which has an effective barrel length of approx 2.41" after you subtract the chamber and OAL of the 9mm round.
f. The 9x23 is wicked hot. WW claims 1450fps and it was right on the money out of my .38 Super 1911 (which chambered and fed it without any trouble, I guess that's pretty common). Surprisingly not much difference with felt recoil in the 1911, more noticeable in the 360J but still nowhere near my friend's M&P 340 with fullhouse .357mags. It does sound completely different out of the 1911, more of a crack than a boom, like a rifle. I must say that I am now a fan - a 124gr bullet going 1448fps out of a 1911 is nothing to sneeze at.
g. I'm thoroughly impressed with the velocities from the Taurus, obviously the tolerances are quite close to produce the same velocity from the Federal 9BPLE that I got from the 9x23 Winchester from the 360. I'd love to try these same 9mm loads in a 940 and compare the results.
In conclusion, if I knew then what I know now would I spend the money to convert my 360J..... hmmmm..... Yes, I think I would still do it. It is lightweight (13oz), has more than acceptable accuracy for it's intended use, and gives me close to 1000fps with my duty load (Federal 9BPLE) with similar recoil to a .38spl +P. Also, I can get .357mag velocities with the 9x23 Winchester with less recoil.
Where do I go from here? Good question, I'd like to try a blank cylinder cut to 9x23 from the start and see what kind of numbers I get but that would probably be cost prohibitive. So, I'll pobably stick with what I've got and be happy. My 360 is still what it was yesterday - light, accurate, reliable, versatile, and easy to handle - with more power than a .38spl, just not as much as I had hoped.
Now, let me know what you guys think!
So, here's the numbers and I'll discuss my thoughts on the results below:
Now, what was clear to me while shooting all of these rounds is that the 9x23 chambering in these conversions is a compromise that doesn't fit anything well, including the 9x23. Since you're starting out with a chamber that is cut for the .38spl (a straight .379"diameter for the entire 1.096" depth) when you recut the chamber for 9x23 (.392" tapering down to .381", but only to a depth of about .870") you end up with gaps at different points in the chamber depending on what caliber you're loading it with. IMO, that is why I got the reduced velocities out of the 360J, I was losing pressure in the chambers and it was evidenced by the soot on the outside of the cartridge cases and some case bulging with some hotter rounds.
So, since I can't think of all of the questions that might be asked, I'll give you a couple of more of my thoughts and then answer or discuss any of your questions or observations:
a. Obviously the 9mm out of a properly chambered snubby is pretty hot compared to the .38spl (Taurus 905 velocities vs S&W 637). IMO, the difference in recoil between the two was negligible, the 9mm is nothing like a .357mag.
b. Given the loss of velocity with the converted cylinder it's a matter of personal opinion if the expense is worth the 150fps difference between the .38spl+P and the hottest 9mm load I had.
c. The current .38 Super loads aren't so super. In fact the velocities I got out of the 1911 weren't much more than you'd expect from the .38acp it was supposed to replace. It does make me want to check out the Corbon loads, though.
d. Barrel length makes a difference with hotter loads, more room for powder to burn = more pressure = more velocity, as evidenced by the Federal 9BPLE numbers out of the Beretta (3.6" barrel) and the HK (4.41" barrel).
e. The cylinder/barrel gap doesn't mean that much. In spite of being a revolver with a short 1.75" barrel, the Taurus 905 velocities were within about 3.5% of the Beretta which has an effective barrel length of approx 2.41" after you subtract the chamber and OAL of the 9mm round.
f. The 9x23 is wicked hot. WW claims 1450fps and it was right on the money out of my .38 Super 1911 (which chambered and fed it without any trouble, I guess that's pretty common). Surprisingly not much difference with felt recoil in the 1911, more noticeable in the 360J but still nowhere near my friend's M&P 340 with fullhouse .357mags. It does sound completely different out of the 1911, more of a crack than a boom, like a rifle. I must say that I am now a fan - a 124gr bullet going 1448fps out of a 1911 is nothing to sneeze at.
g. I'm thoroughly impressed with the velocities from the Taurus, obviously the tolerances are quite close to produce the same velocity from the Federal 9BPLE that I got from the 9x23 Winchester from the 360. I'd love to try these same 9mm loads in a 940 and compare the results.
In conclusion, if I knew then what I know now would I spend the money to convert my 360J..... hmmmm..... Yes, I think I would still do it. It is lightweight (13oz), has more than acceptable accuracy for it's intended use, and gives me close to 1000fps with my duty load (Federal 9BPLE) with similar recoil to a .38spl +P. Also, I can get .357mag velocities with the 9x23 Winchester with less recoil.
Where do I go from here? Good question, I'd like to try a blank cylinder cut to 9x23 from the start and see what kind of numbers I get but that would probably be cost prohibitive. So, I'll pobably stick with what I've got and be happy. My 360 is still what it was yesterday - light, accurate, reliable, versatile, and easy to handle - with more power than a .38spl, just not as much as I had hoped.
Now, let me know what you guys think!
