62 grn round - .223 vs 5.56 - zeroing diff?

[Mossyoakglock]

I was able to shoot my newly built AR this past weekend and loved it. It shot like a dream. I fired both 55 and 62 grn and it seemed more accurate with the 62 grn round. It was .223 as well.

I am looking to stock up on ammo and want to stick with the 62 grn. I've found that the 5.56 is a little cheaper than the .223 too, at least in my area. My question is on the zeroing differences. If I sighted my scope in using .223 62 grn, will I have the same POI with 5.56? Between the 55 and 62 grn there were differences.

Since I sighted in with .223 62 grn, will there be any issues with 5.56 62 grn or will I need to rezero? With both rounds being the same weight I wouldn't think there would be any differences but wasn't sure. I did check and it looks like they both have the same velocities.

[MegademiC]

Always verify zero.

Don't expect green tip surplus ammo to have similar accuracy as a hunting load.

Details like what exact ammo you shot, group size, exact ammo you look to stockpile, and accuracy requirements would help us give you a better answer.

Generally, different weight ammo and velocity will have different poi, but how close is close enough for you?

[Mossyoakglock]

The 55grn was UMC and the 62 grn was Federal American Eagle. The 5.56 62 grn is also American eagle.

3 shot groups where probably within a half-dollar at 100 yards.

my question was more of a general question and looking to find out on average, is there much of a difference between 5.56 and .223 62 grn.

[Onyx Z]

First and foremost, every barrel/rifle shoots different. Each barrel has different harmonics, so there is no way to predict how a certain round will perform without shooting that particular round through that particular barrel/rifle.

5.56 is a higher pressure/velocity round, so they will typically impact higher than a 223 round. There is A LOT more than gravity and bullet weight in play in ballistics, so you may be 5" right, 2" high, or you could be lucky and they might have the exact same POI (point of impact). Ballistics is determined by MANY, MANY more things than bullet velocity and bullet weight.

Really the ONLY way to know is to shoot it.

[turnburglar]

always go out and verify zero, but i bet for practical use the difference will be minimal.

[_Stormin_]

my question was more of a general question and looking to find out on average, is there much of a difference between 5.56 and .223 62 grn.

There is. You're also going to see a difference between individual manufacturers 62 grain loads. American Eagle 62 gr .223 will probably not have the same point of impact as CBC 62 grain .223, or 5.56... Different powders, changes in temperature, so may factors impact where your rounds impact.

Should they all be "close" enough to not lose sleep over it? Probably, but always confirm zeros...

[dbain99]

I can't recommend stocking up in anything I haven't verified. It kinda sucks but I shoot several weights, brands and bullet types per rifle then stock up on the best round per price for the task I want my rifle to preform.
With .223 55gr I've seen as much as a 3" shift in POI among different brands and from 4"+ groups to 3/4" groups out of the same rifle on the same day.


Sent via telegraph with the same fingers I use to sip whiskey.

[cbx]

I'm going to echo what everyone else says. They all shoot different in different rifles.

Hell, I even had an afternoon last Fall that wolf steel case took less elevation than some ball ammo..... Figure that one out.......

Ballistics is usually pretty straight forward. Every once in a while you'll get a wtf moment.

Always verify. If your wanting real accuracy out of your rifle your going to have to try a bunch of loads.

If it was that easy there would only be a handful of factory loadings instead of umpteen zillion.

[Eurodriver]

First and foremost, every barrel/rifle shoots different. Each barrel has different harmonics, so there is no way to predict how a certain round will perform without shooting that particular round through that particular barrel/rifle.

5.56 is a higher pressure/velocity round, so they will typically impact higher than a 223 round. There is A LOT more than gravity and bullet weight in play in ballistics, so you may be 5" right, 2" high, or you could be lucky and they might have the exact same POI (point of impact). Ballistics is determined by MANY, MANY more things than bullet velocity and bullet weight.

Really the ONLY way to know is to shoot it.

In my 600yd thread in the precision semi auto, check out my post. I was surprised because I used your load with 77gr TMKs and BH 5.56 77gr was impacting 5" higher than your loads at 200 yards. What you're saying makes sense, I just thought the over-max loads would have had a higher velocity than "safe" 5.56?

[Mossyoakglock]

Thanks everybody.

I'm going to pick up some other brands and see how they shoot but so far I'm liking the American Eagle .223 62 grn. Going to pick up some 5.56 55 amd 62 grn and give that a try. Are there any brands to stay away from though?

[MegademiC]

Thanks everybody.

I'm going to pick up some other brands and see how they shoot but so far I'm liking the American Eagle .223 62 grn. Going to pick up some 5.56 55 amd 62 grn and give that a try. Are there any brands to stay away from though?

Independence and tula (the steel type). MIL surp is good for most, but if you want tight groups, you will likely find it lacking. Even lot to lot there is great variability.

[MajorLonghorn]

Independence and tula (the steel type). MIL surp is good for most, but if you want tight groups, you will likely find it lacking. Even lot to lot there is great variability.
I thought Independence was supposed to be decent stuff, comparable to Lake City, certainly better than Tula.

[_Stormin_]

There have been some HOT batches of Independence IIRC. I've got some that I've run through and not had an issue, but there have been some threads about it here.

[.46caliber]

There have been some HOT batches of Independence IIRC. I've got some that I've run through and not had an issue, but there have been some threads about it here.

Independence runs very hot. I think I have that thread saved. If memory serves, the lot I had some boxes from chrono'd at 3,000 fps out of my 16".

ETA

Here's the thread with a collection of data:

https://www.m4carbine.net/showthread.php?t=153680

[556BlackRifle]

Here's a crappy camera phone pic from two weeks ago that I took of a target. I was using a 4X scope with 50 yard zero set to -0.4 mrads. At 100 yards, I could not see the point of aim so I was pointing where I thought it should be based on the outline of the target. Also, the On Target software had a hard time with this because: 1_ it wasn't a scan, 2_ the camera angle was tilted and crooked - (so the grouping info is incorrect). Still, you should be able to get an idea of the differences between 55, 62 and 75 gr projectiles. Even though this is a 1/7 barrel, the lighter bullets seemed to do better. I hope this helps.

ETA: These are 5 shot groups and the squares are 1 MOA.

http://img.photobucket.com/albums/v313/Mike16610/02.24.2016_zpsw59pz5lk.jpg

[Pappabear]

Just about any variable can change POI. Even lot numbers of same AMMO. But for center mass home defense, your probably good. That being said, it's easy to verify. Then stock up.

[MegademiC]

Here's a crappy camera phone pic from two weeks ago that I took of a target. I was using a 4X scope with 50 yard zero set to -0.4 mrads. At 100 yards, I could not see the point of aim so I was pointing where I thought it should be based on the outline of the target. Also, the On Target software had a hard time with this because: 1_ it wasn't a scan, 2_ the camera angle was tilted and crooked - (so the grouping info is incorrect). Still, you should be able to get an idea of the differences between 55, 62 and 75 gr projectiles. Even though this is a 1/7 barrel, the lighter bullets seemed to do better. I hope this helps.

ETA: These are 5 shot groups and the squares are 1 MOA.

http://img.photobucket.com/albums/v313/Mike16610/02.24.2016_zpsw59pz5lk.jpg

That 75gr is crazy. I've shot a sub moa 5 shot group with that same ammo out of my 1/7. Possible data point to show each barrel is unique.

[556BlackRifle]

This wouldn't be a good accuracy evaluation through this barrel. My scope just isn't good enough. (at least not for my aging eyes.) It's capable of much greater accuracy than I shot on that day. I've had really good results with PPU ammo in the past so I was really surprised to see that spread.

[Kdubya]

I stumbled across a thread by BFOOSH006 that was very comprehensive. He did comparison tests on just about every mil-surp and common commercial loadings. It was largely focused on velocity, but he did single out really bad and really good ammo for accuracy. Of the FMJ, I believe PMC XTac and IMI in both 55 and 62gr were surprisingly accurate for him. The IMI is 5.56 and the PMC XTac is .223. Again, all barrels are different. But, it might be a good place to start. Use the velocities and try to find a 5.56 load that is close to the velocity of the .223 variant you've been liking. Should be similar in zero in theory. But, you do want to test before stockpiling. Just enjoy the reason to go shoot a new rifle!

https://www.m4carbine.net/showthread.php?158468-Updated-03-21-15-Chrono-Data-for-factory-ammo-from-16-quot-and-20-quot-barrels