POI M855??

[trunkmonkey]

Could someone please tell me in inches where the point of impact would be at 200 yards for a 10.5 inch barrel shooting M855 with a 25 yard bzo?

[Failure2Stop]

I am looking at 7.5 to 8 inches high if you zeroed POA/POI at 25 yd.
It is roughly equivalent to a 300 yard zero (due to low MV).

Would recommend either a 50 or 100 yard zero for CQBRs.
50 yard zero will be about 2 inches low at 200, and is a good overall use zero.
100 yard zero will be about 4 inches low at 200, but will be very flat in the most applicable ranges.

Here is the data I used-
BC- .304 (G1)
62 gr
.224 dia
Muzzle velocity- 2600 f/s- chronograph at 10 feet from muzzle (source data, not generated or verified by me)
Sight height- 2.6"
70 degrees F
29.92 in Hg
Alt- 2000 ft

[markm]

Would recommend either a 50 or 100 yard zero for CQBRs.

Yes. 25 yard zero is not the best route.... especially if you want to be shooting out to 200.

M855 out of a 10.5" barrel might not be the best combo either.

[trunkmonkey]

M855 isn't my choice for anything other than practice. However we don't always have the choice of what we use or have the distance to do the bzo we want.

In this case that barrel length with that round and that distance. And maybe you can alter that temperature to about 115F. Thanks for the info.

[markm]

M855 isn't my choice for anything other than practice. However we don't always have the choice of what we use or have the distance to do the bzo we want.

Gotcha!

[Failure2Stop]

And maybe you can alter that temperature to about 115F.

Nope, but you can.
Teach a man to fish and such. . . ;)
Ballistic Calculator (http://www.eskimo.com/~jbm/calculations/traj/traj.html)

I highly recommend getting solid velocity data from your actual ammo/gun. If you don't have access to a chronograph no big deal, but since ballistic calculators are scientific guesses, the more accurate you are with the input the less wobble you will have in the result.

Anyway, if you zero POI about 1" below POA at 25 yds you will have a rough 50 yd zero.

[trunkmonkey]

Thanks for the resource