TA01 vs TA01NSN question....

[Animal_Mother556]

I am a first-time ACOG owner. I bought a used TA01...not NSN.

Am I going to have some funky ballistics mounting this on a flattop with an ADM mount? I will be shooting 16 inch midlength gas.

[Animal_Mother556]

No one has any info on this?

[Rifleman_04]

The TA01 is for the 20" barrel with 55gr correct?

I have a TA31RCO-2 calibrated for the 855 from a 14.5" or 16" barrel and I switch it between a 16" M4 and a 20" A4 often.

It is close enough out to 375ish with M855 that I don't notice the change in poi on steel plates but when zeroed and running M193 I have to hold low to get hits where I want them with the marks on the reticle. I haven't pushed it any farther than that though.