acog + ammo question

[hossb7]

If I have my TA33-8 ACOG zeroed at 100m with M193, what will the differences on the BDC be when shooting M855?

Thanks!

[Failure2Stop]

Out to about 100 the difference will probably be negligable- probably.
You should rezero for a change in ammuniton type.
Exact POI change is impossible to forecast.

However- if you are simply asking what the drop difference between the two ammo types will be-
first, need to know MV, or at least barrel length
second- the ACOG BDC is a "guesstimate", based off of a 16" barrel shooting M855 (IIRC), though the TA33 may be calculated from different ammo.

here is some data I had laying around for a 20" barrel, just to show the drop difference-
Ammo___100 m___200 m____300 m____400 m____500 m____600 M
M855____0______-2.8______-12.5_____-31.1_____-61.2____-106.1
M193____0______-2.5______-12.1_____-31.3_____-63.7____-114.7
(70 degrees F, 2000' alt, 29.92" Hg, 2.7" sight height, chrono at 15', 0.243 G1 BC for M193 at 3200 fps, 0.304 G1 BC for M855 at 3050 fps.)

As you can see, there is not a terrible about of difference between the two as far as pure math goes. Of course what happens in the air means a lot more than what it looks like on paper, and I have seen where the two are in direct conflict with each other.

[MisterWilson]

Shoot it.

Let us know how it goes.


<-------TA33-R8 owner

[deercop]

I have my 16" LMT M4 1/7", with ACOG TA33-8, zeroed at 100 yds with M193. I am far from counter-sniper capable, and cannot notice a difference in my real world shooting out to 400 yds, which is the longest distance I've tried. The overlapping size of the groups make any difference in calibration negligible.

Perhaps someone more capable than myself could notice a difference.

[Battl3fr0nt]

I would say Zero it for 62gr then shoot the 55gr.. that is what I do.. it works out pretty well I can use the Cheveron just as good but the POI is a bit different but once you learn it you will be fine and its really not that far off at all maby 2"

[hossb7]

I would say Zero it for 62gr then shoot the 55gr.. that is what I do.. it works out pretty well I can use the Cheveron just as good but the POI is a bit different but once you learn it you will be fine and its really not that far off at all maby 2"

2" at what range? 100m?