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.
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.Liberty4Ever said:Note that we measured 165 gr WWB considerably slower than the Awasos data posted by 3wbdriver - 1148 fps vs. 1212 fps.
Good point. Chronograph posts should include ammo type, distance from muzzle, air temperature, altitude, and humidity if known.3wbdriver said: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?
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.3wbdriver said:I'm not disputing what you read at the Konvention.
Me too. I'm Dr. Science. Dr. Science doesn't like discrepancies in data.I'm just trying to figure out why there was such a variation....
Hotter air is less dense than cooler air. If not, hot air balloons wouldn't work.the temperature difference between your data and mine is 25 - 30 degrees, but if anything I would have thought the hotter, heavier air down here would have slowed mine down more.
He definitely got the better end of that deal. He's probably still smiling. It was probably a quasi-religious experience for him.I was blessed to have that guy do some readings for me, and he was stoked to try my Space ModulatOr!
Dude...........your DaMan....!Re: sticky for chronographs of the sub2k
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.
Me too. I'm Dr. Science. Dr. Science doesn't like discrepancies in data.
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.
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.
Well the subbie is still 200 fps faster than a Glock pistol with the same ammo so it's doing something right. ;DLiberty4Ever said:It also seems that my 9mm 115 gr WWB measurements through the SUB-2000 were lower than I remembered them being.
Awasos said:Turns out that I am entirely wrong. ??? My notes indicate that it was 13 degrees F when I shot the WWB 165 grain and the 155 gr Rem. 22 degrees for all the other ammo. Liberty's new bore theory sounds better.
Might be slow, but it would still make you say Ow!adamky said:My Subbie is sloooow