Hey TxCajun, is it possible that we could have a sticky thread for chronograph results on the subbie?  The question comes up over and over and it's hard to keep up with former posts.

And these numbers were posted by a "lurker" named Awasos.  I saved them to a Word document for reference.  Again all .40S&W.  I know there's some 9mm data loaded too.  Post it guys!  
 
 
Remington 155 gr. JHP  
Sub 2k   1431 fps   energy 704 ftlbs  
Sig 229  1188 fps     485 ftlbs  
 
Winchester 165 gr FMJ  
Sub 2k   1212 fps      538 ftlbs  
Sig 229  1017 fps      379 ftlbs  
 
Speer 180 gr Gold Dot HP  
Sub 2k     1163 fps     540 ftlbs  
kahr p40    976 fps     380 ftlbs  
 
Federal Personal Defense 135 gr hydrashok  
sub 2k 1493 fps      667 ftlbs  
Kahr    1204 fps      434 ftlbs  
 
Hornady 180 gr XTP  
Sub 2k 1184 fps     560 ftlbs  
 
Remington 165 gr Golden Sabre  
Sub 2k 1324 fps     642 ftlbs  
 
Federal 180 gr Hydra shok  
Sub 2k  1205 fps    580 ftlbs  
 
Speer 155 gr FMJ  
Sub 2k  1157 fps    460 ftlbs  
 
Federal American Eagle 180 gr FMJ  
Sub 2k   1036 fps   429 ftlbs  
 
 

Quote from Liberty4Ever   on 12/02/06 at 07:00:20:

 
That IS interesting, because it's slower than what I saw the day I got another guy to chrono mine.  Could it be the higher cooler air where you were shooting compared to lower altitude high humidity summer conditions, distance from barrel, or simply variations in the chronos?  Here is the exact data as he printed it for me.  The printout wouldn't make a reliable scan, so I had to enter it by hand.  We moved the chrono about 15 feet away from the barrel after the 2nd or 3rd shot, because the muzzle blast was giving the sensor covers fits.  
 
WWB, .40S&W, 165gr, FMJ.
 
High:  1238.3 - FPS  #004
Low:   1194.8 - FPS  #002
 
SD:  13.3 FPS
CV:    1.1%
 
MAD:  10.8  FPS
 CV:      0.9%
 
AV:  1221.3 FPS
ES:      43.5 FPS
 
#001:  1226.8 FPS
#002:  1194.8 FPS
#003:  1223.2 FPS
#004:  1238.3 FPS
#005:  1234.1 FPS
#006:  1230.6 FPS
#007:  1210.0 FPS
#008:  1228.6 FPS
#009:  1213.1 FPS
#010:  1213.5 FPS
 
I see now that 3 of the last 4 showed a drop off in velocity.  Could this possibly be due to barrel heating?  The shooter was taking about 5 or 10 seconds between shots.  And could someone post the formula for figuring out kinetic energy?

Chrono data SHOULD include temperature and altitude, but I think these are very minor error terms in the muzzle velocity. The altitude was about 900' MSL, and the temperature was about 67 degrees F.
 
The velocity measurements should not vary much from one chronograph to another. They use crystal oscillators that are accurate to a few parts per million.
 
Distance to the chronograph could theoretically change the readings. Ten feet is often used. but 15 feet is now fairly standard and I should strive to do all my chronograph measurements at that distance. At the KKK, I set the chrono about 8-10 feet in front of the firing line. It's possible that hot smoky gas from the muzzle tripped the front sensor slightly before the bullet arrived and the bullet tripped the back sensor, causing the velocity readings to be a bit lower.
 
It also seems that my 9mm 115 gr WWB measurements through the SUB-2000 were lower than I remembered them being.
 
I wanted to post the data so we could start a comparison. With two different data points, it's difficult to know which is right. If there are ten sets of data and nine agree, then we can discard the bad data.
 
I'll be doing a lot more S2K chrono work in the near future, so I'll try to verify the 9mm data and report back.
 
 
Edited to add:
 
Kinetic energy in foot pounds is:
 
(bullet grains X velocity in fps X velocity in fps) / 450437

Quote from 3wbdriver   on 12/02/06 at 11:19:05:

I didn't think you were. Nor am I contesting what anyone else measured. In fact, I mentioned that my numbers seemed lower than I remembered and I only suggested a possible explanation for why my numbers might be low.
 
Quote:

Me too. I'm Dr. Science. Dr. Science doesn't like discrepancies in data.
 
Quote:

Hotter air is less dense than cooler air. If not, hot air balloons wouldn't work.
 
Surprisingly, at the same temperature, humid air is lighter than dry air. That's not intuitive, because water is a lot denser than air, right? The trick is, we need to compare water VAPOR to air. Water vapor is less dense than air. It's not quite as simple as comparing molecular weights because air is a fairly ideal gas and water vapor isn't, but it's still generally true. Water vapor is lighter than an equivalent volume of air.
 
But this air density comparison is more theoretical than practical for our discussion. The differences in air density would have a very minor effect on muzzle velocity measurements. 10-15 feet of air between the muzzle and the chronograph is not going to make a big difference. If we were concerned with first shot accuracy at 500 yards, air density could be significant, but I doubt there's much contribution to changes in muzzle velocity.
 
Quote:

He definitely got the better end of that deal. He's probably still smiling. It was probably a quasi-religious experience for him.
 
I gotta get a .40 SUB.
 
I'm off to reload some more experimental 9mmSUB loads with three new powders I picked up yesterday. My goal is to have the fastest SUB-2000 on the planet (and not blow myself up in the process). After the 9mmSUB tests are concluded, I'll start trying the same wonderful foolishness with a .40SUB load.

My data was most likely obtained during warm weather (I am at work and will check my notes for temperature when I get home).  I often find velocity differences in the same lot of ammo when fired at different temperatures.  Warm ammo (and therefore warm powder) will often have higher pressure (with higher velocity) than cold ammo.  Depends alot on the powder used and that powders temp sensitivity.  For example, Reloader 7 is very temp sensitive while H322 isn't.
 
Alot of other variables may play a part but I bet temperature sensitive powder could be the culprit.
 
John

1148 fps in adamky's .40 S&W SUB-2000 could be lower than 1212 fps for the same ammo in another SUB-2000 because adamky's SUB was fairly new. The SUB-2000s aren't known for highly polished barrels, and maybe adamky's SUB-2000 is still a bit rough and is still undergoing a process of fire polishing the bore?
 
64 fps difference between two SUB-2000s on average is probably a reasonable expectation if we stack the tolerances on several variables, with the more significant possibilities being:
 
Different lots of ammo, with different powder weights, bullet weights, and powder burn rates
 
Different ambient temperatures changing powder burn rate
 
New barrel vs fire polished bore

yeah......it just hasta be the Illudium !