Would accuracy be noticeably affected if...

[lexcruiser 14]

Would accuracy be noticeably affected if I sighted in a rifle using .223, then used it to shoot 5.56, and vice versa?

 

Noticeable difference at 50yds? 100? 200?

 

The scarcity of ammo is making think of how best to sight something in after installing some new optics..

 

My uneducated guess is there may be some difference, but maybe none too noticeable until 100+ yards out.

Interested to hear your thoughts...

[Teky0101 6]

One thing I noticed with AR's is that the point of impact drastically changes based upon the type of ammo and grain you shoot. I would assume since 5.56 is hotter is would carry better in the wind and at distance over a 223. I personally like to shoot a 62 grain bullet since it is better in the winds but it will drop off quicker at longer ranges. I hope this helps!

[lunker 274]

Would accuracy be noticeably affected if I sighted in a rifle using .223, then used it to shoot 5.56, and vice versa?

 

Noticeable difference at 50yds? 100? 200?

 

The scarcity of ammo is making think of how best to sight something in after installing some new optics..

 

My uneducated guess is there may be some difference, but maybe none too noticeable until 100+ yards out.

Interested to hear your thoughts...

 

Accuracy, not necessarily if they are both bullet weights optimized for your barrel twist.

Point of impact, yes. The PMC Bronze 223 I use is loaded light and has a lower impact than M93 of the same weight (although neither is optimal for my 1:7 twist Colt). You are right about it not mattering much until you start going past 100 yards though.

[raz-0 1,262]

It's about bullet weight and velocity.

 

I have some xm193 @ about 3300fps, 55gr JSP loads @ 3100 fps, 55gr fmj @3000-ish, 60gr ballistic tip @3016, 62 gr OTM, 60 grain bonded core (don't remember the muzzle velocities off hand for those, I'd have to look them up). ALl the hand loads are the same 24.3-24.5 grains of tac and loaded to mag length. POI between them all shifts less than 2" at 50 yards. It'd be less, but the otm and cheapie 55gr FMJ throw it off. The 193, 55gr jsp, and 60gr ballistic tip are actually REALLY close to the same poi at that distance because although the velocity for the jsp is lower, it's BC is higher, and it's a more accurate round. This means that although it's POI is probably lower, it's generally wholly contained within the area the 193 will impact. The 60gr ballistic tip is lower BC than both, and doesn't give up that much velocity. It's almost dead on with the xm193. Plugging it into my ballistic calculator has them within 0.1" out to about 250 yards. In reality, shooting with a red dot, they might as well shoot exactly the same out to 100. The cheapie bulk JSP hits about an inch lower, it might be less.

[pbkid6974 1]

it depends on what kind of accuracy you are looking for. shouldnt be a problem if you are looking to hit center mass on a man sized target. if you are looking one hole accuracy find what works best in your rifle and stick with that. i judge accuracy on poa/poi. if your poi hits the same place on the target with the same poa every time, you have a good rifle. adjust your sights to where you want them to line up. .223 and 5.56 are different and should be treated as such.

[lexcruiser 14]

Great info everyone..! Thanks for taking the time to respond. I think I'll stick with xm193 to sight in.. It works well for me and its what I shoot the most.

[phoenix_iii 0]

You're talking more vertical stringing vs. horizontal changes... usually... so not too bad depending on your accuracy demands.

[mipafox 438]

Any change in ammo can produce changes in point of impact. And usually not what you would expect based upon increased/decreased velocity increased/decreased projectile weight. The results are often unexpected. Unless you are loading your own with a specific projectile and simply altering velocities slightly and the rest optimum.