Chrony F-2 / M-2 Chronograph (yellow)

[Leo R]

I bought a
Chrony F-2 / M-2 Chronograph (yellow) I don't know if i set it up right it clocked my 222 at 3749 avg.40 gr bullet on 5 shots 23.2 gr. 8208XBR seemed to fast to me

 

[the foot]

My chrony always gives me a believable number. That 3749 number seems pretty high, but maybe it is true. My question is .222 with that high muzzle velocity??

 

[rcmodel]

I don't think it is possible.

Hodgdon / IMR data says a .223 with a 24" barrel.
(Not a .222.)

Max compressed load of 26.7 grains.
40 grain Nosler.
Gives 3,659 FPS.

Your screens might be too close and measuring muzzle blast.

rc

 

[mokin]

I make sure the my F-1 is flat and set it up around 20 feet from the muzzle. I've found that closer than that and I occasionally get muzzle blast. Also, if it is even just a little not completely unfolded the speeds are very inconsistent. Usually toward the fast side.

 

[g.willikers]

That reading isn't all that much higher than the 40 grain .222 normally runs.
Every gun is different.
It's probably accurate to a reasonable degree.

 

[Hypnogator]

Individual units may vary.

I've had an F1 chrony for a couple of years, gave rather consistent results. Then I left it in AZ when I came back to IA for the summer, so I bought another one to leave at my summer home. The same loads were now chronographing 150-200 fps. faster than previously. Put some of that down to temperature changes, until my new F1 died suddenly and horribly when I shot at a lower target.

Found a used CED Millennium chrony on e-bay for a good price, so I bought it and set it up. Guess what? My velocities are now roughly the same as measured through the old F1 chrony, in the same temperature range as the new F1. I "calibrated" it by firing some LC52 .30 Carbine ammo through my M1 Carbine, and found it was measuring within a few fps. of the ammo's stated velocity. Bottom line is, the second F1 chrony I bought was measuring significantly faster than the other two. Since the CED gave results consistent with military specs, the second F1 chrony was apparently out of spec.

 

[Leo R]

got back to the range put my Chrony f2 out 20 ft worked alot better
velocity avg. 3336 thet what it shod be