Colibri effectiveness

[redneck]

Measuring projectile velocity is done with a chronograph. Most major manufacturers will put the muzzle and hundred yard velocities either on their website or right on the box.
I used simple physics equations for projectile motion to get the 5000 yard calculation. If you add in the exponential decay of the velocity that number will shrink A LOT.
If I get bored enough later to do the hard math (doubtful, I'm on spring break ) I'll check out the CCI site and see if I can get some better calculations.

Oh yeah aimed at a 45 degree angle would give the farthest distance.
You basically look at it like a triangle. All velocity has a vertical and horizontal component.At 45 degrees the horizontal and vertical components are equal, so you have best ratio of air time as the bullet goes up to the top of its arc and then falls back down, to horizontal speed as it travels forard.
Its hard to beleive, but since gravity has the same effect on everything, if a bullet is fired perfectly horizontally at the same time a bullet is dropped from the same height, they hit the ground at the same time. Gives a whole new appreciation for how dog gone fast a bullet really travels.

 

[Stand_Watie]

I think most of what you just said to me went right over my head - now how's that for a gun related pun? Anyway I did a little testing with both the CCI and the Aguila colibri ammo this afternoon and here are my results - tell me if this means anything to you...

35 yards

Colibri ------- 4 inches low average
CCI --------right on the money


50 yards

Colibri --------18 inches low average
CCI --------2 inches low average

75 yards

Colibri --------36 inches low average
CCI --------11.5 inches low average

100 yards

Colibri -------- Unknown/off target completely
CCI ---------29 inches low average

 

[redneck]

I think I can figure out average velocites from the drop, and then get a half assed idea of how fast they lose velocity. Not tonight though, have to work in the morning.
Of course anything I come up with is just theoretical, and possibly not even close to true, I is just a redneck after all. It just worked out that physics related to shooting so I stayed awake for those classes



Now...back to your regularly scheduled yep's, dayum's , an I reckon's

 

[ivanthehunter]

It must have been a hard day at work!!!!!

Anyway-
AFAIK the Super Colibri seem to have a BC of 0.035 to fit the drop in the above post! This gives it a max range of 430yards with terminal energy of 0.7ft/lbs if fired at 29 deg. No more dangerous than a shot gun!

The CCI CB Longs (product code 0038) has a BC of 0.073 (acc to rimfirecentral data) and this would have a max range of 880yards with a terminal energy of 2.2ft/lbs if fired at 31 degs..... too far to chance..

Now-- i wonder how i might degrade the BC on the CCI CB Longs

Yep i know this is an old thread but it needed answering