Extreme POI difference with different ammo. Normal?

[baekacaek]

I'm still kind of new to the gun world so please excuse my newbie question. I zeroed in my scope with a particular ammo (PMC x-tac 5.56 55gr FMJ). Today, I tried a different ammo (wolf gold .223 55gr FMJ) and was surprised that my POI was off by a lot; the round was shooting 7MOA to the right and 6MOA up. I'd understand if it was off either up or down (due to difference in bullet velocity) by a small amount, but I don't understand how it can be off to the right by 7MOA with a same gun.

Is this normal? If it is, can someone explain what's going on here?

[baekacaek]

By the way, I'm shooting an AR15. 16Inch chrome lined barrel with 1:8 twist, in case that matters

[Soginator]

Even m855 can vary by 2-3 mao depending on the brand you are using, and they are supposed to be the same specs. Generally speaking wolf is regarded as plinking ammo. Pick an ammo you want to use, to calibrate your stuff, stick with that when you are trying to be accurate. Use the other stuff when you don't care.

[Ghostrider19]

Is your optic mount tight tight tight? Any chance your optic accidentally took a hit during transport?

[BLK RFL DIV]

25yrds? 100yds? (I assume 100) Did you try the PMC x-tac 5.56 today as well? As stated, maybe something is off with your optic, maybe it is the ammo, maybe something else is incorrect. As you are somewhat new to shooting, it could have possibly been your NPOA, but 7" is rather drastic.

I've documented drastic POA/POI variances with 7.62x39mm (Blog link). I try to zero with one ammo type and stick with it.

[Whiterabbit]

moa is moa at any range.

This is normal. I didn't expect the bullet weights to be so similar, but still. Normal. you should see the difference when shooting pistol.

[BLK RFL DIV]

FYI, when you mount your scope, your want to use a torque wrench and tighten to the correct in/lbs. Tightening as hard as you can is completely incorrect. Additionally, cheap mounts will lead you to your chasing groups = immense frustration.

[BLK RFL DIV]

moa is moa at any range.

This is normal. I didn't expect the bullet weights to be so similar, but still. Normal. you should see the difference when shooting pistol.

Fair enough, but as he is a relatively new shooter, I would still like to know at what range he was shooting at and if he is using the terminology correctly. Additionally, was he dealing with wind, 50yds shouldn't be an issue, but if he was poking paper at 300yds a full value wind will vastly affect POI.

[baekacaek]

Yea I was shooting at 100 yards. The round was shooting 7inches to the right, hence 7MOA.

I'll try shooting both ammo on the same day next time to see if the scope dials got dinged up or something. I doubt it though, as my scope dial has numbers on them, and the numbers haven't changed. I'm using Burris pepr scope mount.

[BLK RFL DIV]

Yea I was shooting at 100 yards. The round was shooting 7inches to the right, hence 7MOA.

I'll try shooting both ammo on the same day next time to see if the scope dials got dinged up or something. I doubt it though, as my scope dial has numbers on them, and the numbers haven't changed. I'm using Burris pepr scope mount.

Did you use a torque wrench?

POA/POI can definitely have a lot of variance with different ammo types, but definitely try shooting the PMC X-TAC next time. If you have the same POA/POI as when you zeroed it before, then you just stick to PMC X-TAC.

[baekacaek]

Did you use a torque wrench?

POA/POI can definitely have a lot of variance with different ammo types, but definitely try shooting the PMC X-TAC next time. If you have the same POA/POI as when you zeroed it before, then you just stick to PMC X-TAC.

Hmm, no I just tighten with a quarter until it's pretty tight.

I also tried shooting with my EOTech that has a QD mount (which I also zeroed using PMC ammo), and that also shot the wolf ammo 6-7 inches to the right and 6 inches up. So I'm pretty convinced that it's not the scope or mount

[BLK RFL DIV]

Hmm, no I just tighten with a quarter until it's pretty tight.

I also tried shooting with my EOTech that has a QD mount (which I also zeroed using PMC ammo), and that also shot the wolf ammo 6-7 inches to the right and 6 inches up. So I'm pretty convinced that it's not the scope or mount

I'm talking about the scope rings, not the cross bolts. Any time you set a scope into place you want to know the manufacturers recommendation and tighten accordingly.

And with that additional information, you confirmed what you saw, so yes, there is that amount of variance between Wolf Gold and PMC X-TAC on your rifle. Interested to know your results when you reconfirm with PMC X-TAC.

[MrPlink]

7 minutes of windage difference?
That sounds extreme to me.

I would make sure nothing got loose or incorrectly adjusted as well.

[vliberatore]

Sounds like it could be a parallax issue

[Mail Clerk]

you right!

I'm still kind of new to the gun world so please excuse my newbie question. I zeroed in my scope with a particular ammo (PMC x-tac 5.56 55gr FMJ). Today, I tried a different ammo (wolf gold .223 55gr FMJ) and was surprised that my POI was off by a lot; the round was shooting 7MOA to the right and 6MOA up. I'd understand if it was off either up or down (due to difference in bullet velocity) by a small amount, but I don't understand how it can be off to the right by 7MOA with a same gun.

Is this normal? If it is, can someone explain what's going on here?

baekacaek,

I exeprience the same thing when I shoot my AR's and different ammo. My problem is that I can't find a consistant brand that's always available like it use to be.

I too like PMC ammo but not the X-Tac version cuz I believe it's too much for my pocket book so I try to always get Bronze instead. Now a days even Bronze is pricey as well so my shooting secessions are shorter.

Anyway for sure your POI will vary a little to allot depending on the brand.
I have noticed European ammo varies allot when it comes to POI on paper.

Mail Clerk