Chrono Data - Federal XM223SP1 62gr Bonded

[Evil1969SS>LS6]

I'm sure many of you are familiar with the Speer Gold Dot 24448 and how it performs, well Doc's post in this thread made my decision to pick up the XM223SP1 since its so much cheaper...

https://www.m4carbine.net/showthread.php?t=73955

Yup...and that's the reason I've been stocking up on this round. Perfect for use through both my BCM 14.5 mid-lengths

[MistWolf]

Would it be correct to assume the 20" rifle the data was taken from has a 5.56 chamber?

[Ironman8]

Would it be correct to assume the 20" rifle the data was taken from has a 5.56 chamber?

Not really sure what difference that would make as the ammo is .223 pressure and not 5.56...am I missing something?

[DRT]

Would it be correct to assume the 20" rifle the data was taken from has a 5.56 chamber?

Yes, per my original post where I indicated it was a 5.56mm.

[MistWolf]

Not really sure what difference that would make as the ammo is .223 pressure and not 5.56...am I missing something?

223 ammunition would have lower pressures and velocities in a 5.56 chamber (as it has a longer leade) than it would in a 223 chamber. I don't know about all 5.56 ammunition, but the Federal 5.56 with the 55 gr bullet is loaded to a longer OAL than the Federal 223 with the same bullet

223 SAAMI pressures are not necessarily lower than 5.56 NATO pressures as they are measured differently

Yes, per my original post where I indicated it was a 5.56mm.

D'OH!! I missed that

[Ironman8]

223 ammunition would have lower pressures and velocities in a 5.56 chamber (as it has a longer leade) than it would in a 223 chamber. I don't know about all 5.56 ammunition, but the Federal 5.56 with the 55 gr bullet is loaded to a longer OAL than the Federal 223 with the same bullet

223 SAAMI pressures are not necessarily lower than 5.56 NATO pressures as they are measured differently



D'OH!! I missed that

Interesting...I didn't know that.

Thanks!

[MistWolf]

Upon further study of the difference between the Federal 223 & 5.56 ammunition, it's come to my attention a correction to my earlier post is in order-

It appears Federal either uses two different types of 55 gr bullets when loading the 223 & the 5.56 or uses the same bullet but with the cannular in a different location. The cannular of the 5.56 bullet is further back from the bullet's tip

[shootist~]

I chronographed lot number 49Q660X005 this morning in a 14.5" DD LW and a 16" Noveske N4 Light. Both are chrome lined barrels. From a velocity standpoint the 14.5" gun was surprisingly slow at < 2,500 FPS. Not sure if it's a slow barrel or if the powder does not perform well at this barrel length.

Temp: ~56*.
Altitude: 5,000'
PACT Chronograph at 10'.
Wind 10+ early. Worse later.


14.5 DD LW - 10 shot string:
(Cold/Dirty barrel.)

Avg - 2,469 fps
H - 2,564
L - 2,405

16" N4 Light - String 1; 11 shots:
(Cold/Clean barrel).

Avg - 2,583
H - 2,622
L - 2,518

[16" N4 Light - String 2; 10 shots:
(Cool/Dirty barrel).

Avg - 2,586
H - 2,629
L - 2,548

It's interesting that the 16" barrel ran over 100 fps faster. This makes a huge difference if shooting any distance at all.

With the 16" N4 and Aimpoint Micro, I got a rough 200M zero using +2" high on the 100 Yd gong. I was then able to get consistent hits by going to the top edge of an 18x18" gong at 300 Meters. Warm and fuzzy on this part.

Temp = 58F
Elevation = 1300'
prochrono @ 15'

Federal XM223SP1
62gr bonded .223
20" Colt 5.56mm 1x7", freefloated with 3x9 Nikon Scope
Lot # 49P659X005

2777
2743
2760
2751
2778
-------
2762 fps ave (relatively mild for a 20" barrel)

[Ironman8]

I'm really interested in seeing the velocity out of a 10.5".

I would think that the velocity would still be high enough to expand reliably, but hopefully I could get a good 100 yds out of it (ballistics wise)

[Tyrantresister]

What were your results, velocity and otherwise, from the 18" barrel, shootist?