Using 75gr while sighted in for 55gr

[OLM-Medic]

I keep my AR-15 sighted in with 55gr M193. This is my ammo choice, besides heavier bullets which I can not afford in large quantities. Since I can not afford much of them, I must keep my AR sighted in with 55gr M193.

I have a very limited amount of Hornady 75gr TAP and since it is known to be a very good antipersonnel round I would like to keep a mag or two for it.

I have my AR sighted for 50/200 yards. Tests show that at 25yards the TAP will shoot almost 2" higher than POA would be with 55gr. I don't think this is that big of a deal since I would mainly just have one magazine of TAP for CQB in my house.

I have no idea how different POA would be out to longer distances though. It is a shame too, since this should be very accurate ammo at longer ranges.

Anyone else have this dillema?

 

[Uncle Krunkle]

You have to buy enough of it to test it at long ranges and learn your holds with 75gr TAP with a 55gr M193 sighted gun. I reload 68gr and 75gr OTM for my AR's. I sight my guns in with my most common load: 68gr Varget: 24.7gr. But I have lots of older 68gr reloads with lower amounts of powders and that stuff has a different point of impact and bullet drop. And all my AR's have different barrel lengths and there's the POI shift to consider with the suppressor. It gets really confusing.

 

[Forest]

. Tests show that at 25yards the TAP will shoot almost 2" higher than POA would be with 55gr. I don't think this is that big of a deal since I would mainly just have one magazine of TAP for CQB in my house.

That has not been my experience at all - in fact when I switch from 55gr to 75gr OTM the shift in POI is neglibable at 50y - it's only at longer range where the difference really shines.

If you're getting a 2" difference at 25 yards, that's not a big ballistic difference between the two rounds (not enough difference in BC and MV) for that kind of shift.