Today, I (finally)....

[Pond, James Pond]

... hit the 300m target with my AR!!

I did do a little jig in the target pit when I finally saw if my hits had been true.

Those who have read my AR escapades will perhaps remember that I was having a devil of a time getting my zero on the AR to get hits on paper at that distance. In fact my AR shooting was horrid to begin with: about 5-6 MOA. It came down to about 4MOA at 100m with some practice and changes to my technique.

The lst outing I had zero'ed at 100M and today I used masking-tape to mark a big target shape at the top of a large piece of paper. I held my reticle on the top of the page, using the taped shape as alignment for my reticle bars.

I fired 15 shots then went down to the target. They were all on paper, about 3-4" right and about 20" down.

This seems like more drop than I would have expected from .223, 200m further on from the 100m zero but I may be wrong. According to an online tutorial it should have been more like about 10". Perhaps my Fiocchi 55gn .224 bullets have dreadful BC values...

Anyway, having measured the drop, I dialled in the appropriate values for elevation and fired again. This time the group of 10 was not so tight, but then I was shooting a bit quicker due to time. They were, however, all in the area of POA.

The first group of 15 shots measured 2.7MOA, which, given a 4x scope, I am pretty pleased. If I remove two very errant shots from the rest of the cluster, that drops to about 1.8MOA.
(I know it is not good practice but they really were way off from an otherwise fairly tight group, by my standards.)

Anyway, all that to say that I am very happy with my outing today. I had a feeling today was the day.

Now, I will shoot at close range to see exactly where my close zero is and I will set my iron sights to the same distance, meaning they should be on 300m also. I will then shoot at 50 and 100 to see where hits land to I can get a good picture of the trajectory for future competitions.

[marine6680]

Good deal.

If it was a nice clustered group, and it was to the right a bit, a couple clicks to bring it center is appropriate.

Slight errors in our zero will show up better at longer range. So get the hits centered well at 300, and they should be well centered at close ranges too.

Some quick number crunching says 15in of drop... So given the fact I used averages to get there, it's possible that 20in drop is normal for that ammo.

And did the group measure 2.7in at 300m? That's less than 1moa

[Pond, James Pond]

And did the group measure 2.7in at 300m? That's less than 1moa

Lord, no!! My typo... Should be MOA not "...

I'll edit the OP.

Good toknow that 20" drop is not a world away from the expected, but it does mean a LOOOT of "hold-under" at 100m.

Perhaps, after all that, I need to set the scope so they hit about 10" low at 300m?

That should give me a little less disparity between hits at 100m and 300m which are the two main longer distances for local IPSC matches.

[marine6680]

2.7 MOA at 300m with a standard AR and standard grade 55gr FMJ... that is something to be happy about. It isn't bad in the least.



If the purpose is competition, and the ranges are known...

You need to look at the strings of fire, the round counts, the ranges, and points.

Then look at your skill at shooting at those ranges. Try to take in account the effect adrenaline will have during actual scored runs.


Then, try to determine which of the shooting stages are your best, and therefor the ones you will get the most points.

Once you know that, you can then determine a zero that works for those stages best. Finding a zero that works with multiple ranges well can be difficult, narrowing the ranges down can help.

If you are accepting that there will be significant holdover on at least one or two distances you will be firing at, then it may be best to try to minimize the holdovers on your best ranges, as a holdover of 20in isn't much different that 15in... but if making that change eliminates holdover at a more important range, then its worth it.

[Pond, James Pond]

Finding a zero that works with multiple ranges well can be difficult, narrowing the ranges down can help.

"Hudson may be right!" (film quote trivia)


Indeed, I was very happy with getting hits at 300. It proves that I and the rifle can do it: not something I was so sure of when I first got it!!

However, yes, I need to consider those ranges. I had hoped that I could just hold a little low at 100 and be on target but 20" is quite a lot.

On the one hand, given my scope's power, having it hit dead on at the furthest range makes life easier as I can see closer targets more clearly and holdover estimations are easier.
By contrast, I will probably be shooting way more stages at 10, 20, 50 and 100m and with my current 300m zero the latter two will probably require holdover to be in the alpha zone.

Perhaps I can set my zero so it is about 10" low at 300m, thus making it about 10 high at 100m. That would just mean putting my crosshairs on the top or bottom of the COMSTOCK target, respectively.

[marine6680]

Whatever works... Works.

Practice will be the key.