Bullet drop difference .223

[sterzenbach]

Hey guys im new to using commercial .223/556 ammo. I finally suckered into an ar, 16in bull barrel match trigger ect.
Ive been shooting American eagle 556 to sight in and play a bit these last few weeks. I got around to playing with loads, nosler 64gr bonded with cfe223 25.80 charge cci SRP. My load is spot on, real tight group at 100 yards, and just barely barely craters the primer. You really have to study it to see.

95% of my shooting over the years has been with my own loads, very little commercial. I did alot of .223 for my remington 700, and I load .308 all day for a variety of rifles.
My Issue is consistently my load is shooting center with the commercial ammo 556 62gr, but about 12in lower. Is this normal for the hotter 556 or what? Both give me tight groups just a different location on paper.
Any input would be greatly appreciated.

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[rick benjamin]

Chronograph
Amazon
Midway
Cabelas

 

[orygun]

Chronograph
Amazon
Midway
Cabelas

Good advice. Just because a load is reaching maximum pressure (or higher) does not mean it's fast...
Cratering primers, even slightly, is likely a sign of high pressures. So, unless your gun has a sloppy firing pin to bolt face fit, you're likely past where you want to be, pressure wise, in that gun.
My bubblegum-umption is that your handload isn't travelling as fast as the factory load, but only a chronograph will confirm.
Ballistics is a goofy science. One thing that can happen in a handgun, which isn't as likely with a rifle, is that a faster bullet can strike the target lower than a slower bullet. This is because of less barrel time of the faster bullet. The lighter bullet exits the barrel before the gun has recoiled as much it will with a bullet that takes longer to exit.
I remember thinking that my handloads were making a certain FPS because the manual said so. When I got a chronograph I learned how wrong I was...

 

[Member 5605]

When speed is unknown.....

 

[rick benjamin]

When speed is unknown.....

DRRC 9-10-2015 no serious injury
no stock remaining ahead of the grip
280 Remington Ackley Improved handloads
Berger VLD 180gr .284


No chronograph
Case separation
No primer cratering observed
Couldn't find a .280 bullet recipe for 280AI above 175 gr
For 175 gr, all these loads are 1+grains higher than maximum recommended.
and then there's the magnum primers.

 

[ChiefStealth]

12in difference in POI, at 100 yards? Wow! I've never seen THAT much difference. I've also shot some of that American Eagle XM193 stuff. Less than an inch vertical difference from my handloads with 55gn Xtreme bulk bullets. About 1 inch higher with Hornady 60gn V-Max.

 

[salmonriverjohn]

View attachment 257374


For 175 gr, all these loads are 1+grains higher than maximum recommended.
and then there's the magnum primers.

You betcha,,, folks sometimes don't stop and consider that when using a magnum primer the load pressure= a one grain increase.
Most of my best accuracy loads are no where near top end or compressed loads

 

[v0lcom13sn0w]

You betcha,,, folks sometimes don't stop and consider that when using a magnum primer the load pressure= a one grain increase.
Most of my best accuracy loads are no where near top end or compressed loads

ALL of my most accurate loads are well under max loads.

 

[jluck]

ALL of my most accurate loads are well under max loads.

99% percent of the time this is true. In my experience.

 

[Member 5605]

Almost smack dab in the middle for mine.

 

[v0lcom13sn0w]

so is slower more accurate or is it knowing theres less felt recoil that impacts how a guy shoots?

both?

 

[2506]

Maybe. Also, finding the most accurate load is one part trial-and-error, one part science, and the rest is alchemy. My 6mm groups get smaller with speed. My 300 WM likes 180gr bullets at 3100fps-- any other weight or speed and accuracy goes out the window. Like everything, there is no single causality.